C.8 Modality Specific Modules
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## C.8 Modality Specific Modules

### C.8.1 Computed Radiography Modules

This Section describes Computed Radiography Series and Image Modules. These Modules contain Attributes that are specific to Computed Radiography images. There is no Computed Radiography Equipment Module.

#### C.8.1.1 CR Series Module

Table C.8-1 contains IOD Attributes that describe a computed radiography series performed on the patient.

Table C.8-1. CR Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Body Part Examined | (0018,0015) | 2 | Text description of the part of the body examined. See Annex L “Correspondence of Anatomic Region Codes and Body Part Examined Defined Terms” in PS3.16 for Defined Terms
View Position | (0018,5101) | 2 | Radiographic view associated with Patient Position (0018,5100). For humans: Defined Terms: AP Anterior/Posterior PA Posterior/Anterior LL Left Lateral RL Right Lateral RLD Right Lateral Decubitus LLD Left Lateral Decubitus RLO Right Lateral Oblique LLO Left Lateral Oblique For animals, capitalized versions with hyphens replaced by underscores of the abbreviations defined in "Smallwood et al. A Nomenclature for Radiographic Projections Used In Veterinary Medicine" shall be used. See CID 7484 “DX View for Animals”, in which these abbreviations are listed. ### Note For example, the Defined Term "CD10DI_CRPRO" would be used for a "Cd10Di-CrPrO" or "caudal 10-degree distal-cranioproximal oblique". The Code String value representation for this attribute constrains the characters to uppercase, digits and underscore.
Filter Type | (0018,1160) | 3 | Label for the type of filter inserted into the x-ray beam
Collimator/grid Name | (0018,1180) | 3 | Label describing any grid inserted.
Focal Spot(s) | (0018,1190) | 3 | Size of the focal spot in mm. For devices with variable focal spot or multiple focal spots, small dimension followed by large dimension.
Plate Type | (0018,1260) | 3 | Label of the type of storage phosphor plates used in this series
Phosphor Type | (0018,1261) | 3 | Label of type of phosphor on the plates

#### C.8.1.2 CR Image Module

Table C.8-2 contains IOD Attributes that describe computed radiography images.

Table C.8-2. CR Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME1 MONOCHROME2
KVP | (0018,0060) | 3 | Peak kilo voltage output of the x-ray generator used
Plate ID | (0018,1004) | 3 | The ID or serial number of the sensing plate upon which the image was acquired
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to center of field of view. ### Note This value is traditionally referred to as Source Object Distance (SOD).
Exposure Time | (0018,1150) | 3 | Time of x-ray exposure in msec
X-Ray Tube Current | (0018,1151) | 3 | X-Ray Tube Current in mA.
Exposure | (0018,1152) | 3 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure in µAs | (0018,1153) | 3 | The exposure expressed in µAs, for example calculated from Exposure Time and X-Ray Tube Current.
Imager Pixel Spacing | (0018,1164) | 3 | Physical distance measured at the front plane of the Image Receptor housing between the center of each pixel. Specified by a numeric pair - row spacing value (delimiter) column spacing value - in mm. In the case of CR, the front plane is defined to be the external surface of the CR plate closest to the patient and radiation source.
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Generator Power | (0018,1170) | 3 | Power in kW to the x-ray generator.
Acquisition Device Processing Description | (0018,1400) | 3 | Describes device-specific processing associated with the image (e.g., Organ Description)
Acquisition Device Processing Code | (0018,1401) | 3 | Code representing the device-specific processing associated with the image (e.g., CR Organ Filtering code)
Cassette Orientation | (0018,1402) | 3 | Orientation of cassette, used to properly position the image for display. Enumerated Values: LANDSCAPE PORTRAIT
Cassette Size | (0018,1403) | 3 | Size of cassette. Defined Terms: 18CMX24CM 8INX10IN 24CMX30CM 10INX12IN 30CMX35CM 30CMX40CM 11INX14IN 35CMX35CM 14INX14IN 35CMX43CM 14INX17IN
Exposures on Plate | (0018,1404) | 3 | Total number of x-ray exposures that have been made on the plate identified in Plate ID (0018,1004)
Relative X-Ray Exposure | (0018,1405) | 3 | Relative x-ray exposure on the plate. Meaning of values is implementation specific. May be used to adjust the dynamic range of the plate digitizer (scanner). ### Note This value is manufacturer-specific. DICOM specifies standard Attributes in Table 10-23 “Exposure Index Macro Attributes”, which are recommended.
Sensitivity | (0018,6000) | 3 | Read out sensitivity. ### Note This value is manufacturer-specific. DICOM specifies standard Attributes in Table 10-23 'Exposure Index Macro', which are recommended.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | Defined CID for the Anatomic Region Sequence is 4009 for humans, and 7482 for animals.
Include Table 10-23 “Exposure Index Macro Attributes” |

### C.8.2 CT Modules

This Section describes the CT Image Module. This Module contains all Attributes that are specific to CT images.

#### C.8.2.1 CT Image Module

The table in this Section contains IOD Attributes that describe CT images.

Table C.8-3. CT Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.2.1.1.1 for specialization.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.8.2.1.1.2 for specialization.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.2.1.1.3 for specialization.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See Section C.8.2.1.1.4 for specialization.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See Section C.8.2.1.1.5 for specialization.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. See Section C.8.2.1.1.6 for specialization.
Rescale Intercept | (0028,1052) | 1 | The value b in relationship between stored values (SV) and the output units. Output units = m*SV+b If Image Type (0008,0008) Value 1 is ORIGINAL and Value 3 is not LOCALIZER, output units shall be Hounsfield Units (HU).
Rescale Slope | (0028,1053) | 1 | m in the equation specified in Rescale Intercept (0028,1052).
Rescale Type | (0028,1054) | 1C | Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). See Section C.11.1.1.2 for Defined Terms and further explanation. Required if the Rescale Type is not HU (Hounsfield Units). May be present otherwise.
KVP | (0018,0060) | 2 | Peak kilo voltage output of the x-ray generator used
Acquisition Number | (0020,0012) | 2 | A number identifying the single continuous gathering of data over a period of time that resulted in this image
Scan Options | (0018,0022) | 3 | Parameters of scanning sequence.
Data Collection Diameter | (0018,0090) | 3 | The diameter in mm of the region over which data were collected
Data Collection Center (Patient) | (0018,9313) | 3 | The x, y, and z coordinates (in the patient coordinate system) in mm of the center of the region in which data were collected. See Section C.8.15.3.6.1.
Reconstruction Diameter | (0018,1100) | 3 | Diameter in mm of the region from within which data were used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region.
Reconstruction Target Center (Patient) | (0018,9318) | 3 | The x, y, and z coordinates (in the patient coordinate system) of the reconstruction center target point as used for reconstruction in mm. See Section C.8.15.3.6.1. ### Note If the reconstructed image is not magnified or panned the value corresponds with the Data Collection Center (Patient) (0018,9313) attribute.
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to isocenter (center of field of view). ### Note This value is traditionally referred to as Source Object Distance (SOD).
Gantry/Detector Tilt | (0018,1120) | 3 | Nominal angle of tilt in degrees of the scanning gantry. Not intended for mathematical computations.
Table Height | (0018,1130) | 3 | The distance in mm of the top of the patient table to the center of rotation; below the center is positive.
Rotation Direction | (0018,1140) | 3 | Direction of rotation of the source when relevant, about nearest principal axis of equipment. Enumerated Values: CW clockwise CC counter clockwise
Exposure Time | (0018,1150) | 3 | Time of x-ray exposure in msec. If Acquisition Type (0018,9302) equals SPIRAL, the value of this attribute shall be Revolution Time (0018,9305) divided by the Spiral Pitch Factor (0018,9311). See Section C.8.15.3.8.1 and Section C.8.15.3.2.1.
X-Ray Tube Current | (0018,1151) | 3 | X-Ray Tube Current in mA.
Exposure | (0018,1152) | 3 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure in µAs | (0018,1153) | 3 | The exposure expressed in µAs, for example calculated from Exposure Time and X-Ray Tube Current.
Filter Type | (0018,1160) | 3 | Label for the type of filter inserted into the x-ray beam.
Generator Power | (0018,1170) | 3 | Power in kW to the x-ray generator.
Focal Spot(s) | (0018,1190) | 3 | Size of the focal spot in mm. For devices with variable focal spot or multiple focal spots, small dimension followed by large dimension.
Convolution Kernel | (0018,1210) | 3 | A label describing the convolution kernel or algorithm used to reconstruct the data
Revolution Time | (0018,9305) | 3 | The time in seconds of a complete revolution of the source around the gantry orbit.
Single Collimation Width | (0018,9306) | 3 | The width of a single row of acquired data (in mm). ### Note Adjacent physical detector rows may have been combined to form a single effective acquisition row.
Total Collimation Width | (0018,9307) | 3 | The width of the total collimation (in mm) over the area of active x-ray detection. ### Note This will be equal the number of effective detector rows multiplied by single collimation width.
Table Speed | (0018,9309) | 3 | The distance in mm that the table moves in one second during the gathering of data that resulted in this image.
Table Feed per Rotation | (0018,9310) | 3 | Motion of the table (in mm) during a complete revolution of the source around the gantry orbit.
Spiral Pitch Factor | (0018,9311) | 3 | Ratio of the Table Feed per Rotation (0018,9310) to the Total Collimation Width (0018,9307).
Exposure Modulation Type | (0018,9323) | 3 | A label describing the type of exposure modulation used for the purpose of limiting the dose. Defined Terms: NONE
Estimated Dose Saving | (0018,9324) | 3 | A percent value of dose saving due to the use of Exposure Modulation Type (0018,9323). A negative percent value of dose savings reflects an increase of exposure.
CTDIvol | (0018,9345) | 3 | Computed Tomography Dose Index (CTDIvol), in mGy according to IEC 60601-2-44, Ed.2.1 (Clause 29.1.103.4), The Volume CTDIvol. It describes the average dose for this image for the selected CT conditions of operation.
CTDI Phantom Type Code Sequence | (0018,9346) | 3 | The type of phantom used for CTDI measurement according to IEC 60601-2-44. Only a single Item is permitted in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4052 “Phantom Devices”.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | Defined CID for the Anatomic Region Sequence is CID 4030 “CT, MR and PET Anatomy Imaged”.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |
Calcium Scoring Mass Factor Patient | (0018,9351) | 3 | The calibration factor for the calcium mass score. These factors incorporate the effects of KV value of the CT image the patient size. machine specific corrections See Section C.8.2.1.1.7.
Calcium Scoring Mass Factor Device | (0018,9352) | 3 | The calibration factors for the calcium mass score of the device. These factors incorporate the effects of KV value of the CT image machine specific corrections This a multi-value attribute, the first value specifies the mass factor for a small patient size, the second value for a medium patient size and the third value for a large patient size. See Section C.8.2.1.1.7.
Energy Weighting Factor | (0018,9353) | 1C | The weighting factor of the data from the primary source in a multiple energy composition image. This factor incorporates the effects of the specific X-Ray source and kV value examination specific characteristics. Required if one Derivation Code Sequence (0008,9215) Item value is (113097, DCM, "Multi-energy proportional weighting"). May be present otherwise.
CT Additional X-Ray Source Sequence | (0018,9360) | 3 | Contains the attributes describing additional acquisition parameters beyond the primary source in a multiple X-Ray source system or a multi-energy acquisition. The primary X-Ray source is specified in other attributes of this module. One or more Items are permitted in this sequence.
>KVP | (0018,0060) | 1 | Peak kilo voltage output of the X-Ray generator used.
>X-Ray Tube Current in mA | (0018,9330) | 1 | Nominal X-Ray tube current in milliamperes.
>Data Collection Diameter | (0018,0090) | 1 | The diameter in mm of the region over which data were collected.
>Focal Spot(s) | (0018,1190) | 1 | Used nominal size of the focal spot in mm.
>Filter Type | (0018,1160) | 1 | Type of filter(s) inserted into the X-Ray beam.
>Filter Material | (0018,7050) | 1 | The X-Ray absorbing material used in the filter.
>Exposure in mAs | (0018,9332) | 3 | The exposure expressed in milliampere seconds, for example calculated from exposure time and X-Ray tube current.
>Energy Weighting Factor | (0018,9353) | 1C | The weighting factor of the data from this additional source in a multiple energy composition image. This factor incorporates the effects of the specific X-Ray source and kV value examination specific characteristics. Required if one Derivation Code Sequence (0008,9215) Item value is (113097, DCM, "Multi-energy proportional weighting"). May be present otherwise.
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.
Include Table 10-27 “RT Equipment Correlation Macro Attributes Description” |

##### C.8.2.1.1 CT Image Attribute Descriptions

###### C.8.2.1.1.1 Image Type

For CT Images, Image Type (0008,0008) is specified to be Type 1.

Defined Terms for Value 3:

AXIAL

  identifies a CT Axial Image

LOCALIZER

  dentifies a CT Localizer Image

### Note

Axial in this context means any cross-sectional image, and includes transverse, coronal, sagittal and oblique images.

###### C.8.2.1.1.2 Samples Per Pixel

Enumerated Values:

1

###### C.8.2.1.1.3 Photometric Interpretation

Enumerated Values:

MONOCHROME1

MONOCHROME2

See Section C.7.6.3.1.2 for definition of these terms.

###### C.8.2.1.1.4 Bits Allocated

Enumerated Values:

16

###### C.8.2.1.1.5 Bits Stored

Enumerated Values:

12

13

14

15

16

###### C.8.2.1.1.6 High Bit

For CT Images, High Bit (0028,0102) shall have be one less than the value sent in Bits Stored.

###### C.8.2.1.1.7 Calcium Scoring Mass Factor Patient and Device

The calibration factors for the Calcium Scoring Mass Factor Patient (0018,9351) and Calcium Scoring Mass Factor Device (0018,9352) attributes are defined by the International Consortium for Multi-Detector CT Evaluation of Coronary Calcium, see McCollough, C.H. "A multi-institutional, multi-manufacturer, international standard for the quantification of coronary artery calcium using cardiac CT".

### C.8.3 MR Modules

This Section describes the MR Image Module. This Module contains all Attributes that are specific to MR images.

#### C.8.3.1 MR Image Module

Table C.8-4 contains the Attributes that describe MR images.

Table C.8-4. MR Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.3.1.1.1 for specialization.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.8.3.1.1.2 for specialization.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.3.1.1.3 for specialization.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See Section C.8.3.1.1.4 for specialization.
Scanning Sequence | (0018,0020) | 1 | Description of the type of data taken. Enumerated Values: SE Spin Echo IR Inversion Recovery GR Gradient Recalled EP Echo Planar RM Research Mode ### Note Multi-valued, but not all combinations are valid (e.g., SE/GR, etc.).
Sequence Variant | (0018,0021) | 1 | Variant of the Scanning Sequence. Defined Terms: SK segmented k-space MTC magnetization transfer contrast SS steady state TRSS time reversed steady state SP spoiled MP MAG prepared OSP oversampling phase NONE no sequence variant
Scan Options | (0018,0022) | 2 | Parameters of scanning sequence. Defined Terms: PER Phase Encode Reordering RG Respiratory Gating CG Cardiac Gating PPG Peripheral Pulse Gating FC Flow Compensation PFF Partial Fourier - Frequency PFP Partial Fourier - Phase SP Spatial Presaturation FS Fat Saturation
MR Acquisition Type | (0018,0023) | 2 | Identification of data encoding scheme. Enumerated Values: 2D frequency x phase 3D frequency x phase x phase
Repetition Time | (0018,0080) | 2C | The period of time in msec between the beginning of a pulse sequence and the beginning of the succeeding (essentially identical) pulse sequence. Required except when Scanning Sequence (0018,0020) is EP and Sequence Variant (0018,0021) is not SK.
Echo Time | (0018,0081) | 2 | Time in ms between the middle of the excitation pulse and the peak of the echo produced (kx=0). In the case of segmented k-space, the TE(eff) is the time between the middle of the excitation pulse to the peak of the echo that is used to cover the center of k-space (i.e.,-kx=0, ky=0).
Echo Train Length | (0018,0091) | 2 | Number of lines in k-space acquired per excitation per image.
Inversion Time | (0018,0082) | 2C | Time in msec after the middle of inverting RF pulse to middle of excitation pulse to detect the amount of longitudinal magnetization. Required if Scanning Sequence (0018,0020) has values of IR.
Trigger Time | (0018,1060) | 2C | Time, in msec, between peak of the R wave and the peak of the echo produced. In the case of segmented k-space, the TE(eff) is the time between the peak of the echo that is used to cover the center of k-space. Required for Scan Options (0018,0022) that include heart gating (e.g., CG, PPG, etc.)
Sequence Name | (0018,0024) | 3 | User defined name for the combination of Scanning Sequence (0018,0020) and Sequence Variant (0018,0021).
Angio Flag | (0018,0025) | 3 | Angio Image Indicator. Primary image for Angio processing. Enumerated Values: Y Image is Angio N Image is not Angio
Number of Averages | (0018,0083) | 3 | Number of times a given pulse sequence is repeated before any parameter is changed
Imaging Frequency | (0018,0084) | 3 | Precession frequency in MHz of the nucleus being addressed
Imaged Nucleus | (0018,0085) | 3 | Nucleus that is resonant at the imaging frequency. Examples: 31P, 1H
Echo Number(s) | (0018,0086) | 3 | The echo number used in generating this image. In the case of segmented k-space, it is the effective Echo Number.
Magnetic Field Strength | (0018,0087) | 3 | Nominal field strength of MR magnet, in Tesla
Spacing Between Slices | (0018,0088) | 3 | Spacing between slices, in mm. The spacing is measured from the center-to-center of each slice.
Number of Phase Encoding Steps | (0018,0089) | 3 | Total number of lines in k-space in the 'y' direction collected during acquisition.
Percent Sampling | (0018,0093) | 3 | Fraction of acquisition matrix lines acquired, expressed as a percent.
Percent Phase Field of View | (0018,0094) | 3 | Ratio of field of view dimension in phase direction to field of view dimension in frequency direction, expressed as a percent.
Pixel Bandwidth | (0018,0095) | 3 | Reciprocal of the total sampling period, in hertz per pixel.
Nominal Interval | (0018,1062) | 3 | Average R-R interval used for the scans, in msec
Beat Rejection Flag | (0018,1080) | 3 | Beat length sorting has been applied. Enumerated Values: Y yes N no
Low R-R Value | (0018,1081) | 3 | R-R interval low limit for beat rejection, in msec
High R-R Value | (0018,1082) | 3 | R-R interval high limit for beat rejection, in msec
Intervals Acquired | (0018,1083) | 3 | Number of R-R intervals acquired.
Intervals Rejected | (0018,1084) | 3 | Number of R-R intervals rejected.
PVC Rejection | (0018,1085) | 3 | Description of type of PVC rejection criteria used.
Skip Beats | (0018,1086) | 3 | Number of beats skipped after a detected arrhythmia.
Heart Rate | (0018,1088) | 3 | Beats per minute.
Cardiac Number of Images | (0018,1090) | 3 | Number of images per cardiac cycle.
Trigger Window | (0018,1094) | 3 | Percent of R-R interval, based on Heart Rate (0018,1088), prescribed as a window for a valid/usable trigger.
Reconstruction Diameter | (0018,1100) | 3 | Diameter in mm. of the region from within which data were used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region.
Receive Coil Name | (0018,1250) | 3 | Receive coil used.
Transmit Coil Name | (0018,1251) | 3 | Transmit coil used.
Acquisition Matrix | (0018,1310) | 3 | Dimensions of the acquired frequency /phase data before reconstruction. Multi-valued: frequency rows\frequency columns\phase rows\phase columns.
In-plane Phase Encoding Direction | (0018,1312) | 3 | The axis of phase encoding with respect to the image. Enumerated Values: ROW phase encoded in rows. COL phase encoded in columns.
Flip Angle | (0018,1314) | 3 | Steady state angle in degrees to which the magnetic vector is flipped from the magnetic vector of the primary field.
SAR | (0018,1316) | 3 | Calculated whole body Specific Absorption Rate in watts/kilogram.
Variable Flip Angle Flag | (0018,1315) | 3 | Flip angle variation applied during image acquisition. Enumerated Values: Y yes N no
dB/dt | (0018,1318) | 3 | The rate of change of the gradient coil magnetic flux density with time (T/s).
Temporal Position Identifier | (0020,0100) | 3 | Temporal order of a dynamic or functional set of Images.
Number of Temporal Positions | (0020,0105) | 3 | Total number of temporal positions prescribed.
Temporal Resolution | (0020,0110) | 3 | Time delta between Images in a dynamic or functional set of Images.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | Defined CID for the Anatomic Region Sequence is 4030.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.

##### C.8.3.1.1 MR Image Attribute Descriptions

###### C.8.3.1.1.1 Image Type

For MR Images, Image Type (0008,0008) is specified to be Type 1.

Defined Terms for Value 3:

DENSITY MAP

DIFFUSION MAP

IMAGE ADDITION

MODULUS SUBTRACT

MPR

OTHER

PHASE MAP

PHASE SUBTRACT

PROJECTION IMAGE

T1 MAP

T2 MAP

VELOCITY MAP

###### C.8.3.1.1.2 Samples Per Pixel

Enumerated Values:

1

###### C.8.3.1.1.3 Photometric Interpretation

Enumerated Values:

MONOCHROME1

MONOCHROME2

See Section C.7.6.3.1.2 for definition of these terms.

###### C.8.3.1.1.4 Bits Allocated

Enumerated Values:

16

### C.8.4 Nuclear Medicine Modules

This Section describes Nuclear Medicine Series, Equipment, and Image Modules. These Modules contain Attributes that are specific to the NM Image IOD.

### Note

There are some cases where it may be necessary to use several SOP Instances to encode a single NM acquisition. For example, the matrix size must remain constant within a SOP instance. Multiple matrix sizes require multiple SOP instances. Similarly, multiple gated stress levels require separate SOP instances for each stress level. However, a receiving AE is not expected to recombine them.

#### C.8.4.1 NM Series Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.4.2 NM Equipment Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.4.3 NM Image Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.4.4 NM Spect Acquisition Image Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.4.5 NM Multi-gated Acquisition Image Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.4.6 NM/PET Patient Orientation Module

Table C.8-5 specifies the Attributes that describe the NM/PET Patient Orientation.

Table C.8-5. NM/PET Patient Orientation Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Patient Orientation Code Sequence | (0054,0410) | 2 | Sequence that describes the orientation of the patient with respect to gravity. See Section C.8.4.6.1.1 for further explanation. Zero or one item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 19 “Patient Orientation”. The Coding Scheme Designator (0008,0102) shall have an Enumerated Value of "99SDM" for historical reasons. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>Patient Orientation Modifier Code Sequence | (0054,0412) | 2C | Patient Orientation Modifier. Required if needed to fully specify the orientation of the patient with respect to gravity. See Section C.8.4.6.1.2 for further explanation. Zero or one item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 20 “Patient Orientation Modifier”. The Coding Scheme Designator (0008,0102) shall have an Enumerated Value of "99SDM" for historical reasons. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
Patient Gantry Relationship Code Sequence | (0054,0414) | 2 | Describes the orientation of the patient with respect to the gantry. See Section C.8.4.6.1.3 for further explanation. Zero or one item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 21 “Patient Equipment Relationship”. The Coding Scheme Designator (0008,0102) shall have an Enumerated Value of "99SDM" for historical reasons. Code Meaning (0008,0104) shall be Type 3 for historical reasons.

##### C.8.4.6.1 NM/PET Patient Orientation Attribute Descriptions

###### C.8.4.6.1.1 Patient Orientation Code Sequence

The Patient Orientation Code Sequence (0054,0410) is used to describe the orientation of the patient with respect to gravity, and is independent of the position in the gantry.

###### C.8.4.6.1.2 Patient Orientation Modifier Code Sequence

The Patient Orientation Modifier Code Sequence (0054,0412) is used to modify or enhance the orientation specified by Patient Orientation Code Sequence (0054,0410).

###### C.8.4.6.1.3 Patient Gantry Relationship Code Sequence

Patient Gantry Relationship Code Sequence (0054,0414) is used to describe the patient direction within the gantry, such as head-first or feet-first. When imaging the extremities, these directions are related to normal anatomic position.

Example: In normal anatomic position, the fingers point towards the feet.

#### C.8.4.7 NM Image Pixel Module

Table C.8-6 specifies the Attributes that describe the pixel data of a NM image.

Table C.8-6. NM Image Pixel Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Samples per Pixel | (0028,0002) | 1 | Number of samples (color planes) in this image. The value shall be 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.4.7.1.1 for further explanation.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. The value shall be the same as the value in Bits Allocated (0028,0100).
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Pixel Spacing | (0028,0030) | 2 | Physical distance in the patient between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing, in mm. See Section 10.7.1.3 for further explanation of the value order.

##### C.8.4.7.1 NM Image Pixel Attribute Descriptions

###### C.8.4.7.1.1 Photometric Interpretation

Enumerated Values:

MONOCHROME2

PALETTE COLOR

See Section C.7.6.3.1.2 for definition of these terms.

#### C.8.4.8 NM Multi-frame Module

Table C.8-7 specifies the Attributes of a NM Multi-frame Image. This module is always included in a NM SOP instance, even if there is only one frame in the image.

A NM Image object is always a multi-dimensional multi-frame image. The order and organization of the frames within each image is defined by the Frame Increment Pointer (0028,0009). The Frame Increment Pointer (0028,0009) references one or more indexing vectors. An indexing vector is a 1 dimensional array with exactly one element for each frame in the image. The value of the nth element in the indexing vector represents the index for the nth frame, in that dimension. Indices are always numbered starting from 1.

### Note

The scheme for encoding a multi-dimensional array of frames into a single image object is as follows. First, the definition of the data element called the Frame Increment Pointer is changed so that it can be multi-valued (i.e., its VM is now 1-n). Each value of Frame Increment Pointer represents one of the dimensions of the array, with the last value representing the most rapidly changing index. Each value of Frame Increment Pointer is the tag of a data element that is an indexing vector. An indexing vector is a 1 dimensional array with exactly one element for each frame in the image. The value of the nth element in the indexing vector represents the index for the nth frame, in that dimension. For example, suppose you are encoding a Dynamic image consisting of 2 phases (containing 5 and 2 frames, respectively), from each of two detectors, using one isotope, which gives a total of 14 frames in the image. For a Dynamic image, the Frame Increment Pointer is defined as:Frame Increment Pointer = Energy Window Vector (0054,0010) \ Detector Vector (0054,0020) \ Phase Vector (0054,0030) \ Time Slice Vector (0054,0100). Pixel Data (7FE0,0010) would contain the frames in the following order:

Frame | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14
Energy Window # | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
Detector # | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2
Phase # | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 2 | 2
Time Slice # | 1 | 2 | 3 | 4 | 5 | 1 | 2 | 1 | 2 | 3 | 4 | 5 | 1 | 2

and the four vectors would be defined as:

Energy Window Vector = 1,1,1,1,1,1,1,1,1,1,1,1,1,1

Detector Vector = 1,1,1,1,1,1,1,2,2,2,2,2,2,2

Phase Vector = 1,1,1,1,1,2,2,1,1,1,1,1,2,2

Time Slice Vector = 1,2,3,4,5,1,2,1,2,3,4,5,1,2

The receiver can tell the relationship of all the frames from these four vectors. For instance, looking at the 11th value in these four vectors tells you that the 11th frame in this multi-frame object is time slice 4 of phase 1 from detector 2 and isotope 1.

The Energy Window, Detector, Phase, Rotation, R-R Interval, and Time Slot Vectors have corresponding sequence elements that contain exactly one sequence item for each of the index values in the vector. The sequence item contains a set of data elements that are specific to that group of frames, but change from one group to the next. In the above example there would be a detector sequence element, an isotope sequence element and a phase sequence element (for dynamics, no frame sequence element is needed). The detector and phase sequence elements would contain two sequence items (because there were 2 detectors and 2 phases).

Table C.8-7. NM Multi-frame Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Increment Pointer | (0028,0009) | 1 | Contains the Data Element Tags of one or more frame index vectors. See Section C.8.4.8.1.1 for further specialization.
Energy Window Vector | (0054,0010) | 1C | An array that contains the energy window number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Energy Window Vector (0054,0010). See Section C.8.4.8.1.2 for specialization.
Number of Energy Windows | (0054,0011) | 1 | Number of energy window groupings. See Section C.8.4.8.1.2 for specialization.
Detector Vector | (0054,0020) | 1C | An array that contains the detector number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Detector Vector (0054,0020). See Section C.8.4.8.1.3 for specialization.
Number of Detectors | (0054,0021) | 1 | Number of detectors. See Section C.8.4.8.1.3 for specialization.
Phase Vector | (0054,0030) | 1C | An array that contains the phase number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Phase Vector (0054,0030). See Section C.8.4.8.1.4 for specialization.
Number of Phases | (0054,0031) | 1C | Number of phases. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Phase Vector (0054,0030). See Section C.8.4.8.1.4 for specialization.
Rotation Vector | (0054,0050) | 1C | An array that contains the rotation number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Rotation Vector (0054,0050). See Section C.8.4.8.1.5 for specialization.
Number of Rotations | (0054,0051) | 1C | Number of rotations. Required if Image Type (0008,0008), Value 3 is TOMO,GATED TOMO,RECON TOMO, or RECON GATED TOMO. See Section C.8.4.8.1.5 for specialization.
R-R Interval Vector | (0054,0060) | 1C | An array that contains the R-R interval number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for R-R Interval Vector (0054,0060). See Section C.8.4.8.1.6 for specialization.
Number of R-R Intervals | (0054,0061) | 1C | Number of R-R intervals. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for R-R Interval Vector (0054,0060). See Section C.8.4.8.1.6 for specialization.
Time Slot Vector | (0054,0070) | 1C | An array that contains the time slot number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Time Slot Vector (0054,0070). See Section C.8.4.8.1.7 for specialization.
Number of Time Slots | (0054,0071) | 1C | Number of time slots. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Time Slot Vector (0054,0070). See Section C.8.4.8.1.7 for specialization.
Slice Vector | (0054,0080) | 1C | An array that contains the spatial slice number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Slice Vector (0054,0080). See Section C.8.4.8.1.8 for specialization.
Number of Slices | (0054,0081) | 1C | Number of slices. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Slice Vector (0054,0080). See Section C.8.4.8.1.8 for specialization.
Angular View Vector | (0054,0090) | 1C | An array that contains the angular view number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Angular View Vector (0054,0090). See Section C.8.4.8.1.9 for specialization.
Time Slice Vector | (0054,0100) | 1C | An array that contains the time slice number for each frame. Required if the value of Frame Increment Pointer (0028,0009) includes the Tag for Time Slice Vector (0054,0100). See Section C.8.4.8.1.10 for specialization.

### Note

Per the rules in PS3.5, if a data element of Type 1C or 2C is not required, it shall not be included.

##### C.8.4.8.1 NM Multi-frame Attribute Descriptions

###### C.8.4.8.1.1 Frame Increment Pointer

By definition, NM Images are multi-dimensional Multi-frame Images. The value of Frame Increment Pointer (0028,0009) contains the Tag for one or more frame indexing vectors. This determines the number of dimensions of frame indices in the image, and the order in which these indices vary from one frame to the next, with the last Tag indicating the most rapidly changing index. The Enumerated Values for Frame Increment Pointer (0028,0009) are determined by Image Type (0008,0008) Value 3, as shown in Table C.8-8.

Table C.8-8. Enumerated Values for Frame Increment Pointer

Image Type (0008,0008) Value 3 | Frame Increment Pointer (0028,0009)
--- | ---
STATIC or WHOLE BODY | 0054H 0010H \ 0054H 0020H Sequencing is by Energy Window Vector (0054,0010), Detector Vector (0054,0020).
DYNAMIC | 0054H 0010H \ 0054H 0020H \ 0054H 0030H \ 0054H 0100H Sequencing is by Energy Window Vector (0054,0010), Detector Vector (0054,0020), Phase Vector (0054,0030), Time Slice Vector (0054,0100)
GATED | 0054H 0010H \ 0054H 0020H \ 0054H 0060H \ 0054H 0070H Sequencing is by Energy Window Vector (0054,0010), Detector Vector (0054,0020), R-R Interval Vector (0054,0060), Time Slot Vector (0054,0070)
TOMO | 0054H 0010H \ 0054H 0020H \ 0054H 0050H \ 0054H 0090H Sequencing is by Energy Window Vector (0054,0010), Detector Vector (0054,0020), Rotation Vector (0054,0050), Angular View Vector (0054,0090)
GATED TOMO | 0054H 0010H \ 0054H 0020H \ 0054H 0050H \ 0054H 0060H \ 0054H 0070H \ 0054H 0090H Sequencing is by Energy Window Vector (0054,0010), Detector Vector (0054,0020), Rotation Vector (0054,0050), R-R Interval Vector (0054,0060), Time Slot Vector (0054,0070), Angular View Vector (0054,0090).
RECON TOMO | 0054H 0080H Sequencing is by Slice Vector (0054,0080)
RECON GATED TOMO | 0054H 0060H \ 0054H 0070H \ 0054H 0080H Sequencing is by R-R Interval Vector (0054,0060), Time Slot Vector (0054,0070), Slice Vector (0054,0080)

###### C.8.4.8.1.2 Number of Energy Windows and Energy Window Vector

Number of Energy Windows (0054,0011) is the number of distinct energy window groupings acquired in this image. See Section C.8.4.10.1. When Image Type (0008,0008), Value 3, is RECON TOMO or RECON GATED TOMO, then the Number of Energy Windows (0054,0011) shall be 1.

Energy Window Vector (0054,0010) is an indexing vector. The value of the nth element of this vector is the energy window number for the nth frame in this image, and shall have a value from 1 to Number of Energy Windows (0054,0011).

###### C.8.4.8.1.3 Number of Detectors and Detector Vector

Number of Detectors (0054,0021) is the number of separate detectors that differentiate the frames in this image. When Image Type (0008,0008), Value 3, is RECON TOMO or RECON GATED TOMO, then the Number of Detectors (0054,0021) shall be 1.

### Note

Number of Detectors (0054,0021) does not necessarily represent the actual number of detectors used during data acquisition.

Example 1: In a TOMO acquisition in which frames from 2 or more detectors are interleaved to form one continuous set of frames, then no distinction is made between frames on the basis of which detector created them. In this case, the Number of Detectors (0054,0021) would be 1.

Example 2: In a WHOLE BODY acquisition in which a single detector acquires anterior and posterior views in two separate passes, the Number of Detectors (0054,0021) would be 2.

Detector Vector (0054,0020) is an indexing vector. The value of the nth element of this vector is the detector number of the nth frame in this image, and shall have a value from 1 to Number of Detectors (0054,0021).

###### C.8.4.8.1.4 Number of Phases and Phase Vector

Number of Phases (0054,0031) is the number of dynamic phases, independent of the number of Detectors and Isotopes. See Section C.8.4.14 for definition of a phase.

Phase Vector (0054,0030) is an indexing vector. The value of the nth element of this vector is the phase number of the nth frame in this image, and shall have a value from 1 to Number of Phases (0054,0031).

###### C.8.4.8.1.5 Number of Rotations and Rotation Vector

Number of Rotations (0054,0051) is the number of separate rotations. See Section C.8.4.12 for definition of a rotation. When Image Type (0008,0008), Value 3, is RECON TOMO, GATED TOMO or RECON GATED TOMO, then the Number of Rotations (0054,0051) shall be 1.

Rotation Vector (0054,0050) is an indexing vector. The value of the nth element of this vector is the rotation number of the nth frame in this image, and shall have a value from 1 to Number of Rotations (0054,0051).

###### C.8.4.8.1.6 Number of R-R Intervals and R-R Interval Vector

Number of R-R Intervals (0054,0061) is the number of ranges of heartbeat durations collected. A gated acquisition may employ one R-R Interval to collect data from normal beats, a second R-R Interval to collect data from ectopic beats, and possibly others. Each R-R Interval accepts beats whose duration is greater than its Low R-R Value (0018,1081) and shorter than its High R-R Value (0018,1082). Beats that do not fall within these ranges may be accepted by another R-R Interval, or may be rejected.

The Number of R-R Intervals (0054,0061) is the total number of such ranges.

R-R Interval Vector (0054,0060) is an indexing vector. The value of the nth element of this vector is the interval number of the nth frame in this image, and shall have a value from 1 to Number of R-R Intervals (0054,0061).

###### C.8.4.8.1.7 Number of Time Slots and Time Slot Vector

Number of Time Slots (0054,0071) is the number of frames into which each gating event is divided in a gated acquisition. For example, in a cardiac gated acquisition, data from a number of heartbeats are then combined by summing together the first frames from all beats into a summed first frame, all the second frames into a summed second frame, and so on. The result has the same number of frames as the Number of Time Slots in each beat.

Time Slot Vector (0054,0070) is an indexing vector. The value of the nth element of this vector is the time slot number of the nth frame in this image, and shall have a value from 1 to Number of Time Slots (0054,0071).

###### C.8.4.8.1.8 Number of Slices and Slice Vector

Number of Slices (0054,0081) is the number of slices in each separate volume.

### Note

For images with Image Type (0008,0008), Value 3, equal to RECON GATED TOMO this implies that Number of Slices (0054,0081) is the same for all R-R Intervals and Time Slots.

Slice Vector (0054,0080) is an indexing vector. The value of the nth element of this vector is the slice number of the nth frame in this image, and shall have a value from 1 to Number of Slices (0054,0081).

###### C.8.4.8.1.9 Angular View Vector

Angular View Vector (0054,0090) is an indexing vector. The value of the nth element of this vector is the angular view number of the nth frame in this image. If Image Type (0008,0008), Value 3, is TOMO or GATED TOMO, then the value shall be from 1 to Number of Frames in Rotation (0054,0053).

###### C.8.4.8.1.10 Time Slice Vector

Time Slice Vector (0054,0100) is an indexing vector. The value of the nth element of this vector is the time slice number of the nth frame in this image, and shall have a value from 1 to Number of Frames in Phase (0054,0033).

#### C.8.4.9 NM Image Module

Table C.8-9 contains the Attributes that describe Nuclear Medicine Images.

Table C.8-9. NM Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.4.9.1.1 for specialization.
Image ID | (0054,0400) | 3 | User or equipment generated Image identifier.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5 Required if Lossy Compression has been performed on the Image. May be present otherwise.
Counts Accumulated | (0018,0070) | 2 | Sum of all gamma events for all frames in the image. See Section C.8.4.9.1.2 for specialization.
Acquisition Termination Condition | (0018,0071) | 3 | Description of how the data collection was stopped. Defined Terms: CNTS counts DENS density MANU manual OVFL data overflow TIME time TRIG physiological trigger See Section C.8.4.9.1.3 for specialization.
Table Height | (0018,1130) | 3 | The height of the patient table in mm. The range and values of this element are determined by the manufacturer. Should not be included if Image Type (0008,0008), Value 3, is TOMO,GATED TOMO,RECON TOMO or RECON GATED TOMO.
Table Traverse | (0018,1131) | 3 | Location of the patient table (or gantry relative to the table) in mm. The range and values of this element are determined by the manufacturer. Should not be included if Image Type (0008,0008), Value 3, is TOMO,GATED TOMO,RECON TOMO or RECON GATED TOMO.
Actual Frame Duration | (0018,1242) | 1C | Elapsed time for data acquisition in msec. Required if Image Type (0008,0008) Value 3 is: WHOLE BODY or STATIC. See Section C.8.4.9.1.4 for specialization.
Count Rate | (0018,1243) | 3 | Maximum count rate achieved during the acquisition in counts/sec.
Processing Function | (0018,5020) | 3 | Code or description of processing functions applied to the data.
Corrected Image | (0028,0051) | 3 | One or more values that indicate which, if any, corrections have been applied to the image. Corrections are applied to all frames in the image. Defined Terms: UNIF flood corrected COR center of rotation corrected NCO non-circular orbit corrected DECY decay corrected ATTN attenuation corrected SCAT scatter corrected DTIM dead time corrected NRGY energy corrected LIN linearity corrected MOTN motion corrected CLN count loss normalization; Any type of normalization applied to correct for count loss in Time Slots.
Whole Body Technique | (0018,1301) | 3 | The type of scan performed. Used only if Image Type (0008,0008), Value 3, contains the value WHOLE BODY. Enumerated Values: 1PS one pass 2PS two pass PCN patient contour following employed MSP multiple static frames collected into a whole body frame
Scan Velocity | (0018,1300) | 2C | The speed of the camera motion over the body in mm/sec. Required if Image Type (0008,0008) Value 3 contains the value WHOLE BODY.
Scan Length | (0018,1302) | 2C | Size of the imaged area in the direction of scanning motion, in mm. Required if Image Type (0008,0008) Value 3 contains the value WHOLE BODY.
Trigger Source or Type | (0018,1061) | 3 | Text indicating trigger source. Defined Terms: EKG
Include Table 10-7 “General Anatomy Optional Macro Attributes” | No Context ID for the Anatomic Region Sequence is defined.
Real World Value Mapping Sequence | (0040,9096) | 3 | The mapping of stored values to associated real world values. One or more Items are permitted in this sequence.
>Include Table C.7.6.16-12b “Real World Value Mapping Item Macro Attributes” | Defined CID for Measurement Units Code Sequence is 84 "PET Units for Real World Value Mapping".
Scan Progression Direction | (0054,0501) | 3 | The anatomical order in which the slices were acquired. Enumerated Values: FEET_TO_HEAD Slices closest to the patient's feet were acquired first. HEAD_TO_FEET Slices closest to the patient's head were acquired first.

### Note

1. Content Date (0008,0023) and Content Time (0008,0033) are included in the General Image Module, Table C.7-7, whenever the images are temporally related. For this purpose, all NM Images are considered temporally related, so that these elements are included in an NM Image.

2. Referenced Overlay Sequence (0008,1130) and Referenced Curve Sequence (0008,1145) were previously included in this Module as optional Attributes but have been retired. See PS3.3-2004. Referenced Image Real World Value Mapping Sequence (0040,9094) was previously used in this Module to enclose the Real World Value Mapping Sequence (0040,9096) but has been retired. See PS3.3-2011.

##### C.8.4.9.1 NM Image Module Attribute Descriptions

###### C.8.4.9.1.1 Image Type

For NM images, Image Type (0008,0008) Value 3 is specified to be Type 1.

Enumerated Values for Value 3:

STATIC

DYNAMIC

GATED

WHOLE BODY

TOMO

GATED TOMO

RECON TOMO

RECON GATED TOMO

Enumerated Values for Value 4:

EMISSION

TRANSMISSION

### Note

For NM images, Image Type (0008,0008) Value 1 will be ORIGINAL for all raw data and reconstructed images. DERIVED may be appropriate for some other results images.

For NM images, Image Type (0008,0008) Value 2 will be PRIMARY.

###### C.8.4.9.1.2 Counts Accumulated

Counts Accumulated (0018,0070) is the total of all gamma events accumulated in all frames of this Image. This attribute applies to acquisition data, and often does not apply to processed images (DERIVED, SECONDARY).

###### C.8.4.9.1.3 Acquisition Termination Condition

Acquisition Termination Condition (0018,0071) is the method of acquisition termination that was actually applied to the data collection.

Defined Terms:

CNTS

  preset count limit was reached

DENS

  preset count density was reached

MANU

  acquisition was terminated manually

OVFL

  acquisition was terminated automatically by pixel data overflow condition

TIME

  preset time limit was reached

TRIG

  preset number of physiological triggers was reached

###### C.8.4.9.1.4 Actual Frame Duration

Actual Frame Duration (0018,1242) is defined as the elapsed time in msec for a single frame of an acquisition. For some types of multi-frame images, Actual Frame Duration (0018,1242) may have a more specialized meaning as defined in the appropriate IOD Module.

#### C.8.4.10 NM Isotope Module

Table C.8-10 contains Attributes that describe the isotope administered for the acquisition.

Table C.8-10. NM Isotope Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Energy Window Information Sequence | (0054,0012) | 2 | Sequence of Items that describe the energy window groups used. Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of Energy Windows (0054,0011). The first item corresponds to frames with value of 1 in the Energy Window Vector (0054,0010), the second item with value 2, etc.
>Energy Window Name | (0054,0018) | 3 | A user defined name that describes this Energy Window.
>Energy Window Range Sequence | (0054,0013) | 3 | Sequence of Items that describes this energy window group. One or more Items are permitted in this Sequence.
>>Energy Window Lower Limit | (0054,0014) | 3 | The lower limit of the energy window in KeV. See Section C.8.4.10.1.1 for further explanation.
>>Energy Window Upper Limit | (0054,0015) | 3 | The upper limit of the energy window in KeV. See Section C.8.4.10.1.2 for further explanation.
Radiopharmaceutical Information Sequence | (0054,0016) | 2 | Sequence of Items that describe isotope information. Zero or more Items shall be included in this sequence.
>Radionuclide Code Sequence | (0054,0300) | 2 | Sequence that identifies the radionuclide. Zero or one item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 18 “Isotopes in Radiopharmaceuticals”. The Coding Scheme Designator (0008,0102) shall have an Enumerated Value of "99SDM" for historical reasons. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>Radiopharmaceutical Route | (0018,1070) | 3 | Route of injection.
>Administration Route Code Sequence | (0054,0302) | 3 | Sequence that identifies the administration route for the radiopharmaceutical. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 11 “Route of Administration”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>Radiopharmaceutical Volume | (0018,1071) | 3 | Volume of injection in cubic cm.
>Radiopharmaceutical Start Time | (0018,1072) | 3 | Time of start of injection. See Section C.8.4.10.1.5 for further explanation.
>Radiopharmaceutical Stop Time | (0018,1073) | 3 | Time of end of injection. See Section C.8.4.10.1.6 for further explanation.
>Radionuclide Total Dose | (0018,1074) | 3 | Total amount of radionuclide injected. See Section C.8.4.10.1.7 for further explanation.
>Radiopharmaceutical Administration Event UID | (0008,3012) | 3 | Unique identification of the administration of the radiopharmaceutical to the patient. ### Note The UID is the same Radiopharmaceutical Administration Event UID that is in the Radiopharmaceutical Radiation Dose Report.
>Calibration Data Sequence | (0054,0306) | 3 | Sequence that contains calibration data. One or more Items are permitted in this Sequence.
>>Energy Window Number | (0054,0308) | 1 | The Item number in the Energy Window Information Sequence to which the following calibration data relates. The Items are numbered starting from 1.
>>Syringe Counts | (0018,1045) | 3 | Pre-injection syringe count rate in counts/sec. See Section C.8.4.10.1.8 for further explanation.
>>Residual Syringe Counts | (0054,0017) | 3 | Post-injection residue syringe count rate in counts/sec. See Section C.8.4.10.1.9 for further explanation.
>Radiopharmaceutical | (0018,0031) | 3 | Name of the radiopharmaceutical.
>Radiopharmaceutical Code Sequence | (0054,0304) | 3 | Sequence that identifies the radiopharmaceutical. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 25 “Radiopharmaceuticals”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
Intervention Drug Information Sequence | (0018,0026) | 3 | Sequence of Items that describes the intervention drugs used. One or more Items are permitted in this sequence.
>Intervention Drug Name | (0018,0034) | 3 | Name of intervention drug.
>Intervention Drug Code Sequence | (0018,0029) | 3 | Sequence that identifies the intervention drug name. Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 10 “Interventional Drug”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>Administration Route Code Sequence | (0054,0302) | 3 | Sequence that identifies the administration route for the intervention drug. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 11 “Route of Administration”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>Intervention Drug Start Time | (0018,0035) | 3 | Time of administration of the intervention drug, using the same time base as for Acquisition Time (0008,0032).
>Intervention Drug Stop Time | (0018,0027) | 3 | Time of completion of administration of the intervention drug, using the same time base as for Acquisition Time (0008,0032).
>Intervention Drug Dose | (0018,0028) | 3 | Intervention drug dose, in mg.

##### C.8.4.10.1 NM Isotope Module Attribute Descriptions

###### C.8.4.10.1.1 Energy Window Lower Limit

Energy Window Lower Limit (0054,0014) is the acquisition energy window lower limit in KeV for acceptance of scintillation events into this Isotope.

###### C.8.4.10.1.2 Energy Window Upper Limit

Energy Window Upper Limit (0054,0015) is the acquisition energy window upper limit in KeV for acceptance of scintillation events into this Isotope.

###### C.8.4.10.1.3 (Retired)

###### C.8.4.10.1.4 (Retired)

###### C.8.4.10.1.5 Radiopharmaceutical Start Time

Radiopharmaceutical Start Time (0018,1072) is the actual time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as for Acquisition Time (0008,0032).

###### C.8.4.10.1.6 Radiopharmaceutical Stop Time

Radiopharmaceutical Stop Time (0018,1073) is the actual ending time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as for Acquisition Time (0008,0032).

###### C.8.4.10.1.7 Radionuclide Total Dose

Radionuclide Total Dose (0018,1074) is the radiopharmaceutical dose administered to the patient measured in MegaBecquerels (Mbq) at the Radiopharmaceutical Start Time.

###### C.8.4.10.1.8 Syringe Counts

Syringe Counts (0018,1045) is the pre-injection syringe acquisition count rate measured in counts/sec, corrected to Acquisition Time (0008,0032) if necessary.

###### C.8.4.10.1.9 Residual Syringe Counts

Residual Syringe Counts (0054,0017) is the syringe acquisition count rate following patient injection, measured in counts/sec, corrected to Acquisition Time (0008,0032) if necessary.

###### C.8.4.10.1.10 (Retired)

###### C.8.4.10.1.11 (Retired)

#### C.8.4.11 NM Detector Module

Table C.8-11 contains IOD Attributes that describe Nuclear Medicine Detectors used to produce an image.

Table C.8-11. NM Detector Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Detector Information Sequence | (0054,0022) | 2 | Sequence of Items that describe the detectors used. Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of Detectors (0054,0021). The first item corresponds to frames with value of 1 in Detector Vector (0054,0020), the second item with value 2, etc.
>Collimator/Grid Name | (0018,1180) | 3 | Label describing the collimator used (LEAP, hires, etc.)
>Collimator Type | (0018,1181) | 2 | Collimator type. Defined Terms: PARA Parallel (default) PINH Pinhole FANB Fan-beam CONE Cone-beam SLNT Slant hole ASTG Astigmatic DIVG Diverging NONE No collimator UNKN Unknown
>Field of View Shape | (0018,1147) | 3 | Shape of the field of view of the Nuclear Medicine detector. Defined Terms: RECTANGLE ROUND HEXAGONAL
>Field of View Dimension(s) | (0018,1149) | 3 | Dimensions of the field of view, in mm. If Field of View Shape (0018,1147) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of a circumscribed circle.
>Focal Distance | (0018,1182) | 2 | Focal distance, in mm. A value of 0 means infinite distance for parallel collimation. See Section C.8.4.11.1.1 for further specialization.
>X Focus Center | (0018,1183) | 3 | Center of focus along a row. See Section C.8.4.11.1.2 for further explanation.
>Y Focus Center | (0018,1184) | 3 | Center of focus along a column. See Section C.8.4.11.1.2 for further explanation.
>Zoom Center | (0028,0032) | 3 | The amount of offset from (0,0) applied to each pixel in the image before application of the zoom factor, specified by a numeric pair: row value (delimiter) column value (in mm). See Section C.8.4.11.1.3 for further explanation.
>Zoom Factor | (0028,0031) | 3 | The amount of magnification applied to each pixel in the image, specified by a numeric pair: row value (delimiter) column value. See Section C.8.4.11.1.4 for further explanation.
>Center of Rotation Offset | (0018,1145) | 3 | Average center of rotation offset of Nuclear Medicine detector in mm. See Section C.8.4.11.1.5 for further explanation.
>Gantry/Detector Tilt | (0018,1120) | 3 | Angle of tilt in degrees of the detector. See Section C.8.4.11.1.6 for further explanation.
>Distance Source to Detector | (0018,1110) | 2C | Distance in mm from transmission source to the detector face. Required if Image Type (0008,0008) Value 4 is TRANSMISSION and Value 3 is not any of TOMO,GATED TOMO,RECON TOMO or RECON GATED TOMO.
>Start Angle | (0054,0200) | 3 | Position of the detector about the patient for the start of the acquisition, in degrees. Zero degrees is referenced to the origin at the patient's back. Viewing from the patient's feet, angle increases in a counter-clockwise direction (detector normal rotating from the patient's back towards the patient's left side). Should not be included if Image Type (0008,0008) Value 3 is TOMO, GATED TOMO, RECON TOMO or RECON GATED TOMO.
>Radial Position | (0018,1142) | 3 | Radial distance of the detector from the center of rotation, in mm. Should not be included if Image Type (0008,0008) Value 3 is TOMO, GATED TOMO, RECON TOMO or RECON GATED TOMO.
>Image Orientation (Patient) | (0020,0037) | 2 | The direction cosines of the first row and the first column with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
>Image Position (Patient) | (0020,0032) | 2 | The x, y, and z coordinates of the upper left hand corner (center of the first voxel transmitted) of the image, in mm. See Section C.7.6.2.1.1 for further explanation.
>View Code Sequence | (0054,0220) | 3 | Sequence that describes the projection of the anatomic region of interest on the image receptor. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 26 “Nuclear Medicine Projections”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.
>>View Modifier Code Sequence | (0054,0222) | 2C | View Modifier. Required if needed to fully specify the View. Zero or one Item shall be included in this sequence.
>>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 23 “Cranio-Caudad Angulation”. Code Meaning (0008,0104) shall be Type 3 for historical reasons.

##### C.8.4.11.1 NM Detector Attribute Descriptions

###### C.8.4.11.1.1 Focal Distance

Focal Distance (0018,1182) for NM Image data is the focal distance, in mm for converging or diverging collimators, measured from the front face of the detector to the focus. Positive values indicate converging and negative values indicate diverging collimators. A value of 0 means infinite distance for parallel collimation.

###### C.8.4.11.1.2 Focus Center

X Focus Center (0018,1183) and Y Focus Center (0018,1184) for NM Image data is used to define the projection of the focus for a converging or diverging collimator within the un-zoomed Field of View. It is defined in mm for row and column relative to the center of the un-zoomed Field of View.

###### C.8.4.11.1.3 Zoom Center

Zoom Center (0028,0032) is the offset between the un-zoomed camera field of view and field of view, measured from the center of the un-zoomed camera field of view to the center the of the zoomed field of view. The offset is measured in mm in the un-zoomed camera FOV dimensions. Positive values are to the right and down from the un-zoomed center, as viewed from the image plane. When this attribute is not given, the Zoom Center is assumed to be 0\0.

###### C.8.4.11.1.4 Zoom Factor

Zoom Factor (0028,0031) is the magnification factor that was used during the acquisition. When this attribute is not given, it is assumed to be 1.0\1.0.

### Note

Zoom Factor (0028,0031) is informational only. Pixel Spacing (0028,0030) already takes account of this and any other changes to pixel size.

###### C.8.4.11.1.5 Center of Rotation Offset

Center of Rotation Offset (0018,1145) is the average amount of offset in mm between the Detector Field of View center and the physical center of rotation of the gantry for circular orbital scans. Positive values indicate the physical center is to the right of the image plane center.

If:

1. Image Type (0008,0008) Value 3 is TOMO or GATED TOMO, and

2. Corrected Image (0028,0051) does not include the value "COR", and

3. Center of Rotation Offset (0018,1145) is non-zero,

then the receiver should assume that Center of Rotation correction has not already been done.

If the Center of Rotation Offset is zero, no correction shall be applied.

###### C.8.4.11.1.6 Gantry/Detector Tilt

Gantry/Detector Tilt (0018,1120) for NM Image data is the angle in degrees of the detector face relative to the patient's major (Head to Feet) axis (or the table supporting the patient). Positive tilt is towards the patient's feet.

#### C.8.4.12 NM Tomo Acquisition Module

This Module applies to a TOMO Multi-frame Image. This module is present when Image Type (0008,0008) Value 3, is equal to TOMO, GATED TOMO, RECON TOMO, or RECON GATED TOMO. The elements found in this module describe the acquisition of the Image.

Table C.8-12. NM Tomo Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Rotation Information Sequence | (0054,0052) | 2 | Sequence of Items that describe TOMO rotational groups. A new rotation is defined whenever the direction of the detector motion changes, or Table Traverse (0018,1131) changes. Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of Rotations (0054,0051). If Rotation Vector (0054,0050) is present, the first item corresponds to frames with value of 1 in Rotation Vector (0054,0050), the second item with value 2, etc.
>Start Angle | (0054,0200) | 1 | Position of the detector about the patient for the start of this rotation, in degrees. Zero degrees is referenced to the origin at the patient's back. Viewing from the patient's feet, angle increases in a counter-clockwise direction (detector normal rotating from the patient's back towards the patient's left side).
>Angular Step | (0018,1144) | 1 | The angular scan arc step between views of the TOMO acquisition, in degrees. See Section C.8.4.12.1.1 for further explanation.
>Rotation Direction | (0018,1140) | 1 | Direction of rotation of the detector about the patient. See Start Angle (0054,0200) for further explanation of direction. Enumerated Values: CW clockwise (decreasing angle) CC counter-clockwise (increasing angle).
>Scan Arc | (0018,1143) | 1 | The effective angular range of the scan data in degrees. The value shall be positive.
>Actual Frame Duration | (0018,1242) | 1 | Nominal acquisition time per angular position, in msec.
>Radial Position | (0018,1142) | 3 | Radial distance of the detector from the center of rotation, in mm. It shall have a single value that is an average value for this rotation, or it shall have one value per angular view.
>Distance Source to Detector | (0018,1110) | 2C | Distance in mm from transmission source to the detector face. Required if Image Type (0008,0008) Value 4 is TRANSMISSION.
>Number of Frames in Rotation | (0054,0053) | 1 | Number of angular views in this rotation.
>Table Traverse | (0018,1131) | 3 | Location of the patient table (or gantry relative to the table) in mm. The range and values of this element are determined by the manufacturer.
>Table Height | (0018,1130) | 3 | The distance in mm of the top of the patient table to the center of rotation. Table height below the center of rotation has a positive value.
Type of Detector Motion | (0054,0202) | 3 | Describes the detector motion during acquisition. Enumerated Values: STEP AND SHOOT Interrupted motion, acquire only while stationary CONTINUOUS Gantry motion and acquisition are simultaneous and continuous ACQ DURING STEP Interrupted motion, acquisition is continuous

##### C.8.4.12.1 NM Tomo Acquisition Attribute Descriptions

###### C.8.4.12.1.1 Angular Step

Angular Step (0018,1144) is the nominal frame-to-frame incremental angle for TOMO and GATED TOMO acquisition images, defined in degrees. Angular Step (0018,1144) shall be a positive number. Summation of Angular Step values is not defined to give accurate Angular Position or Scan Arc values. The Angular Step is the effective angular spacing between resultant frames of the Multi-framed planar image data.

#### C.8.4.13 NM Multi-gated Acquisition Module

Table C.8-13 contains Attributes that describe a multi-gated acquisition image performed on the patient. This refers to frames acquired while the patient is connected to a gating device.

Table C.8-13. NM Multi-Gated Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Beat Rejection Flag | (0018,1080) | 3 | Heart beat duration sorting has been applied. Enumerated Values: Y yes N no
PVC Rejection | (0018,1085) | 3 | Description of type of arrhythmic beat rejection criteria used.
Skip Beats | (0018,1086) | 3 | Number of beats skipped after a detected arrhythmia
Heart Rate | (0018,1088) | 3 | Average number of heart beats per minute for the collection period for these frames. This shall include all accepted beats as well as rejected beats.
Gated Information Sequence | (0054,0062) | 2C | Sequence of Items that describe R-R intervals. Each gated interval is defined by an upper and lower range of heart beat durations. Required if the Frame Increment Pointer (0028,0009) contains the Tag for R-R Interval Vector (0054,0060). Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of R-R Intervals (0054,0061). The first item corresponds to frames with value of 1 in the R-R Interval Vector (0054,0060), the second item with value 2, etc.
>Trigger Time | (0018,1060) | 3 | Time interval measured in msec from the start of the R-wave to the beginning of the data taking.
>Cardiac Framing Type | (0018,1064) | 3 | Description of type of framing performed. See Section C.7.6.18.1.1.1 for description and Defined Terms.
>Data Information Sequence | (0054,0063) | 2 | Sequence of Items that describe gating criteria. Zero or more Items shall be included in this sequence. See Section C.8.4.13.1.1.
>>Frame Time | (0018,1063) | 1 | Nominal time per individual frame in msec.
>>Nominal Interval | (0018,1062) | 3 | Average duration of accepted beats, in msec.
>>Low R-R Value | (0018,1081) | 3 | R-R interval lower limit for beat rejection, in msec
>>High R-R Value | (0018,1082) | 3 | R-R interval upper limit for beat rejection, in msec
>>Intervals Acquired | (0018,1083) | 3 | Number of heartbeats that fall within Low R-R Value (0018,1081) and High R-R Value (0018,1082), and were therefore accepted and contribute gamma events to this R-R Interval.
>>Intervals Rejected | (0018,1084) | 3 | Number of heartbeats that fall outside Low R-R (0018,1081) and High R-R Value (0018,1082), and do not contribute gamma events to this R-R Interval. However, they may contribute gamma events to other R-R Intervals.
>>Time Slot Information Sequence | (0054,0072) | 2C | Sequence of Items that describe Time Slot Information. Required if the Frame Increment Pointer (0028,0009) contains the Tag for Time Slot Vector (0054,0070). Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of Time Slots (0054,0071). The first item corresponds to frames with value of 1 in the Time Slot Vector (0054,0070), the second item with value 2, etc.
>>>Time Slot Time | (0054,0073) | 3 | The total amount of time, in msec, that the acquisition accumulates gamma events into this frame. See Section C.8.4.13.1.2.

##### C.8.4.13.1 NM Multi-gated Acquisition Attribute Descriptions

###### C.8.4.13.1.1 Data Information Sequence

Data Information Sequence (0054,0063) shall contain a single sequence item that applies to the sum of all angular views, except when Image Type (0008,0008) Value 3 is GATED TOMO. In this case it shall have either a single item that applies to the sum of all angular views, or it shall have one item for each angular view.

###### C.8.4.13.1.2 Time Slot Time

The Time Slot Time (0054,0073) records the effective imaging time of each Time Slot. For example, if some of the accepted beats are shorter than others then the last frames may not receive a contribution from the shorter beats. The Time Slot Time for a Time Slot is the total acquisition time for that Time Slot. It is approximately equal to Frame Time (0018,1063) multiplied by the number of accepted beats contributing to the Time Slot.

#### C.8.4.14 NM Phase Module

Table C.8-14 contains Attributes that describe dynamic phases of a dynamic acquisition image performed on the patient. This module is present only when Image Type (0008,0008), Value 3, is equal to DYNAMIC. A phase is defined as a collection of frames in which the acquisition time per frame and the time delay between frames remains constant. A new phase shall be defined whenever there is a change in the time between frames, the acquisition time per frame, or the position of the patient relative to the detector.

Table C.8-14. NM Phase Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Phase Information Sequence | (0054,0032) | 2C | Sequence of Items that describes each dynamic phase. Required if the Frame Increment Pointer (0028,0009) contains the Tag for Phase Vector (0054,0030). Zero or more Items shall be included in this sequence. The number of items shall be equal to Number of Phases (0054,0031). The first item corresponds to frames with value of 1 in Phase Vector (0054,0030), the second item with value 2, etc.
>Phase Delay | (0054,0036) | 1 | Time paused between the last frame of the previous phase and the first frame of this phase, in msec.
>Actual Frame Duration | (0018,1242) | 1 | Nominal time of acquisition per individual frame, in msec.
>Pause Between Frames | (0054,0038) | 1 | Time paused between each frame of this phase (in msec).
>Number of Frames in Phase | (0054,0033) | 1 | Number of frames in this phase.
>Trigger Vector | (0054,0210) | 3 | An array of trigger times when gating information is acquired simultaneously with the dynamic image data. See Section C.8.4.14.1.1 for further explanation.
>Number of Triggers in Phase | (0054,0211) | 1C | The number of entries in Trigger Vector (0054,0210) for this phase. Required if Trigger Vector (0054,0210) is present.
>Phase Description | (0054,0039) | 3 | Description of this phase of the Dynamic image. Enumerated Values: FLOW WASHOUT UPTAKE EMPTYING EXCRETION

##### C.8.4.14.1 NM Phase Module Attributes Description

###### C.8.4.14.1.1 Trigger Vector

Trigger Vector (0054,0210) is an array containing a list of the inter-trigger interval times in milliseconds in the order in which they were acquired, with the first being measured from the start time of the first frame of the image data in the Phase. If this element is used, the start times are required to be the same so that a mathematical correlation can be made between trigger times and frame start times.

#### C.8.4.15 NM Reconstruction Module

Table C.8-15 contains Attributes that describe Nuclear Medicine reconstructed volumes. Reconstructed volumes are created by applying a transformation (reconstruction) process to the acquired TOMO frames. This module is present only when Image Type (0008,0008) Value 3 is equal to RECON TOMO or RECON GATED TOMO.

Table C.8-15. NM Reconstruction Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Spacing Between Slices | (0018,0088) | 2 | Spacing between slices, in mm, measured from center-to-center of each slice along the normal to the first image. The sign of the Spacing Between Slices (0018,0088) determines the direction of stacking. The normal is determined by the cross product of the direction cosines of the first row and first column of the first frame, such that a positive spacing indicates slices are stacked behind the first slice and a negative spacing indicates slices are stacked in front of the first slice. See Image Orientation (0020,0037) in the NM Detector module.
Reconstruction Diameter | (0018,1100) | 3 | Diameter, in mm, of the region from within which the data was used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region.
Convolution Kernel | (0018,1210) | 3 | A label describing the convolution kernel or algorithm used to reconstruct the data.
Slice Thickness | (0018,0050) | 2 | Nominal slice thickness, in mm.
Slice Location | (0020,1041) | 3 | Relative position of the image plane expressed in mm. See Section C.7.6.2.1.2 for further explanation.
Slice Progression Direction | (0054,0500) | 3 | Describes the anatomical direction that slices are progressing as the slices are considered in order (as defined by Slice Vector (0054,0080)). Meaningful only for cardiac images. When View Code Sequence (0054,0220) indicates a short axis view, then the Enumerated Values are: Enumerated Values: APEX_TO_BASE BASE_TO_APEX

### C.8.5 Ultrasound Modules

This Section describes Ultrasound Frame of Reference and Image Modules. These Modules contain Attributes that are specific to Ultrasound images.

#### C.8.5.1 US Frame of Reference Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.5.2 US Region Calibration (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.5.3 US Image Module (Retired)

This Section was defined in a previous version of the DICOM Standard. The Section is now retired.

#### C.8.5.4 US Frame of Reference Module

This Section was defined in a previous version of the DICOM Standard. The Section is now retired. See PS3.3-2003.

#### C.8.5.5 US Region Calibration Module

The US Region Calibration Module has been introduced into the ultrasound IOD to provide access to the full range of data that may be present in a single US image. US images often contain multiple regions that have independent data regions, e.g., quad screen loops that may have different calibration information. The data presented in the various regions of a US image can represent a multiplicity of physical parameters, e.g., spatial distance, blood velocity, time, volume, etc., and these are often contained in the value of the pixel itself. It is therefore imperative that physical information be available for the various regions of a single region independent of each other.

Table C.8-17 contains IOD Attributes that describe an ultrasound region calibration.

Table C.8-17. US Region Calibration Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Sequence of Ultrasound Regions | (0018,6011) | 1 | Defines a sequence of Ultrasound Regions. One or more Items shall be included in this Sequence.
>Region Location Min x0 | (0018,6018) | 1 | The bounds of a rectangle specifying the location of the region, x0,y0,x1,y1. See Section C.8.5.5.1.14 for further explanation.
>Region Location Min y0 | (0018,601A) | 1 | The bounds of a rectangle specifying the location of the region, x0,y0,x1,y1. See Section C.8.5.5.1.14 for further explanation.
>Region Location Max x1 | (0018,601C) | 1 | The bounds of a rectangle specifying the location of the region, x0,y0,x1,y1. See Section C.8.5.5.1.14 for further explanation.
>Region Location Max y1 | (0018,601E) | 1 | The bounds of a rectangle specifying the location of the region, x0,y0,x1,y1. See Section C.8.5.5.1.14 for further explanation.
>Physical Units X Direction | (0018,6024) | 1 | The physical units of the dimensions of the region. See Section C.8.5.5.1.15 for Enumerated Values.
>Physical Units Y Direction | (0018,6026) | 1 | The physical units of the dimensions of the region. See Section C.8.5.5.1.15 for Enumerated Values.
>Physical Delta X | (0018,602C) | 1 | The physical value increments per positive X pixel increment. The units are as specified in the Physical Units X Direction (0018,6024). See Section C.8.5.5.1.17 for further explanation.
>Physical Delta Y | (0018,602E) | 1 | The physical value increments per positive Y pixel increment. The units are as specified in the Physical Units Y Direction (0018,6026). See Section C.8.5.5.1.17 for further explanation.
>Reference Pixel x0 | (0018,6020) | 3 | This coordinate pair, x0,y0, defines the location of a virtual "reference" pixel. See Section C.8.5.5.1.16 for further explanation.
>Reference Pixel y0 | (0018,6022) | 3 | This coordinate pair, x0,y0, defines the location of a virtual "reference" pixel. See Section C.8.5.5.1.16 for further explanation.
>Reference Pixel Physical Value X | (0018,6028) | 3 | The Physical Value at the reference pixel x location. The units are specified in the Physical Units field.
>Reference Pixel Physical Value Y | (0018,602A) | 3 | The Physical Value at the reference pixel y location. The units are specified in the Physical Units field.
>Region Spatial Format | (0018,6012) | 1 | The spatial organization of the data within the region. See Section C.8.5.5.1.1 for Enumerated Values.
>Region Data Type | (0018,6014) | 1 | The type of data within the region. See Section C.8.5.5.1.2 for Enumerated Values.
>Region Flags | (0018,6016) | 1 | Flags used for special handling of the region. See Section C.8.5.5.1.3 for Enumerated Values and further explanation.
>Pixel Component Organization | (0018,6044) | 1C | Describes how the components of a pixel can be described. Required if pixel component calibration exists for this region. See Section C.8.5.5.1.4 for Enumerated Values and further explanation.
>Pixel Component Mask | (0018,6046) | 1C | This value is ANDed with the composite pixel code for each pixel within the region, then shifted right by the number of contiguous least significant zeros in the mask to obtain what will be referred to as the "Shifted Masked Composite Pixel Code" (SMCPC). Required if Pixel Component Organization = Bit aligned. See Section C.8.5.5.1.5 for further explanation.
>Pixel Component Range Start | (0018,6048) | 1C | Defines the start of the numeric range of values within the composite pixel where calibration is to be defined by the "pixel physical calibration table". To be used only when ranges are used to describe the portion of the composite pixel. Required if Pixel Component Organization = Ranges.
>Pixel Component Range Stop | (0018,604A) | 1C | Defines the stop of the numeric range of values within the composite pixel where calibration is to be defined by the "pixel physical calibration table". To be used only when ranges are used to describe the portion of the composite pixel. Required if Pixel Component Organization = Ranges.
>Pixel Component Physical Units | (0018,604C) | 1C | The physical units to be applied to the pixel component. Required if Pixel Component Organization exists. See Section C.8.5.5.1.6 for further explanation.
>Pixel Component Data Type | (0018,604E) | 1C | The type of data for the pixel component. Required if Pixel Component Organization exists. See Section C.8.5.5.1.7 for further explanation.
>Number of Table Break Points | (0018,6050) | 1C | The number of break point coordinate pairs used to describe a piece wise linear curve. Required if Pixel Component Organization equals 0 or 1. Otherwise not used. See Section C.8.5.5.1.8 for further explanation.
>Table of X Break Points | (0018,6052) | 1C | An array of X values used to create the piece wise linear curve. Required if Pixel Component Organization equals 0 or 1. Otherwise not used. See Section C.8.5.5.1.9 for further explanation.
>Table of Y Break Points | (0018,6054) | 1C | An array of Y values used to create the piece wise linear curve. Required if Pixel Component Organization equals 0 or 1. Otherwise not used. See Section C.8.5.5.1.9 for further explanation.
>Number of Table Entries | (0018,6056) | 1C | The number of entries in the Table of Pixel Values. Required if the value of Pixel Component Organization (0018,6044) is 2 or 3. Otherwise not used. See Section C.8.5.5.1.11 for further explanation.
>Table of Pixel Values | (0018,6058) | 1C | A table of Pixel Values used in conjunction with the Table of Parameter Values (0018,605A) or Pixel Value Mapping Code Sequence (0040,9098) to provide a mapping from Pixel Value to a real world value. Required if the Pixel Component Organization equals 2. Otherwise not used. See Section C.8.5.5.1.12 for further explanation.
>Table of Parameter Values | (0018,605A) | 1C | A table of Parameter Values used in conjunction with the Table of Pixel Values (0018,6058) to provide a mapping from Pixel Value to Parameter Value. Required if the value of Pixel Component Organization (0018,6044) is 2. Otherwise not used. See Section C.8.5.5.1.13 for further explanation
>Pixel Value Mapping Code Sequence | (0040,9098) | 1C | Sequence that, in conjunction with the Table of Pixel Values (0018,6058), provides a mapping from a Pixel Value to an associated Coded Concept. One or more Items shall included in this sequence. The number of Items shall be equal to the value of Number of Table Entries (0018,6056). Required if the value of Pixel Component Organization (0018,6044) is 3 (Code Sequence look up). See Section C.8.5.5.1.18 for further explanation.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | For IVUS Baseline CID 3497 “IVUS Arterial Morphology”; no Baseline CID is defined otherwise.
>Transducer Frequency | (0018,6030) | 3 | The manufacturer defined description of center frequency of the interrogating ultrasound energy. The units are kilohertz.
>Pulse Repetition Frequency | (0018,6032) | 3 | The ultrasound pulse repetition frequency, as defined by the manufacturer, used to collect data in the region. The units are in hertz.
>Doppler Correction Angle | (0018,6034) | 3 | The Doppler correction angle. The units are degrees.
>Steering Angle | (0018,6036) | 3 | The steering angle, as defined by the manufacturer, used for a steered 2D image. The units are degrees.
>Doppler Sample Volume X Position | (0018,6039) | 3 | The x displacement, in pixels, from the Reference pixel to the center of the Doppler sample volume.
>Doppler Sample Volume Y Position | (0018,603B) | 3 | The y displacement, in pixels, from the Reference pixel to the center of the Doppler sample volume.
>TM-Line Position x0 | (0018,603D) | 3 | The starting and ending coordinates pairs of the m-line. Where the X0,Y0are the starting point and X1,Y1are the end point of the tm-line. See Section C.8.5.5.1.10 for further explanation.
>TM-Line Position y0 | (0018,603F) | 3 | The starting and ending coordinates pairs of the m-line. Where the X0,Y0are the starting point and X1,Y1are the end point of the tm-line. See Section C.8.5.5.1.10 for further explanation.
>TM-Line Position x1 | (0018,6041) | 3 | The starting and ending coordinates pairs of the m-line. Where the X0,Y0are the starting point and X1,Y1are the end point of the tm-line. See Section C.8.5.5.1.10 for further explanation.
>TM-Line Position y1 | (0018,6043) | 3 | The starting and ending coordinates pairs of the m-line. Where the X0,Y0are the starting point and X1,Y1are the end point of the tm-line. See Section C.8.5.5.1.10 for further explanation.

##### C.8.5.5.1 US Region Calibration Attribute Descriptions

###### C.8.5.5.1.1 Region Spatial Format

Values for Region Spatial Format (0018,6012) indicate the spatial organization of the data within the region.

Enumerated Values:

0000H

  None or not applicable

0001H

  2D (tissue or flow)

0002H

  M-Mode (tissue or flow)

0003H

  Spectral (CW or PW Doppler)

0004H

  Wave form (physiological traces, Doppler traces,…)

0005H

  Graphics

###### C.8.5.5.1.2 Region Data Type

Values for Region Data Type (0018,6014) indicate the type of data within the region.

Enumerated Values:

0000H

  None or not applicable

0001H

  Tissue

0002H

  Color Flow

0003H

  PW Spectral Doppler

0004H

  CW Spectral Doppler

0005H

  Doppler Mean Trace

0006H

  Doppler Mode Trace

0007H

  Doppler Max Trace

0008H

  Volume Trace

000AH

  ECG Trace

000BH

  Pulse Trace

000CH

  Phonocardiogram Trace

000DH

  Gray bar

000EH

  Color bar

000FH

  Integrated Backscatter

0010H

  Area Trace

0011H

  d(area)/dt

0012H

  Other Physiological (Amplitude vs. Time) input

###### C.8.5.5.1.3 Region Flags

Region Flags (0018,6016) specify characteristics of US Regions.

Bit 0 of the Region Flags specifies the relative priority of the pixel component calibration specified by an US Region in the case where the US Region intersects with other US Regions. The calibration supplied by one or more of the regions may not be valid in the area that they intersect.

Enumerated Values for Bit 0 (lsb):

1

  Region pixels are low priority

0

  Region pixels are high priority

A high priority region overwrites data of a low priority region when they overlap, thus invalidating any pixel component calibration specified for a low priority region. pixel component calibration of overlapping regions of the same priority is indeterminate where they overlap. Figure C.8-6 shows an example of intersecting regions.

Figure C.8-6. Intersecting Spatial Format Regions and Overlapping Measurement

In this example, Region B is Color Flow while Region A is Tissue Echo. If Region B Color Flow values share the same bit planes as Region A Tissue Echo values, then it is indeterminate whether a pixel in this region is a Color Flow pixel or a Tissue Echo pixel. Since the pixels of the Color Flow region overwrite those of the Tissue Echo region, the Region Flag of the Tissue Echo region is assigned low priority and the Region Flag of the color region is assigned high priority. This means that if both the Tissue Echo and Color Flow regions define pixel component calibration that only the calibration specified by the Color Flow region can be applied to the pixel data value at Point X.

The measurement in Figure C.8-6 is a line between Point Y and Point Z. Both points are in Region A so the distance between them can be calculated using the Region A scaling (assuming that Region A defines both the Physical Units X Direction and Y Direction as being cm). If the points are in Region B, and hence also in Region A, it is still possible to calculate the distance because the region scaling is identical in both regions. The lower priority of Region B only applies to its pixel component calibration, not its X and Y direction scaling.

Enumerated Values for Bit 1 Scaling Protection:

1

  Protected

0

  Not Protected

Ultrasound systems should set this to 1 if the image is scaled automatically by the ultrasound system. If the image is frame-grabbed and scaling is not available then it should be set to 0. If the region is protected, the region can not be manually rescaled. That is the data defined by the region calibration Module can not be overridden by a reader of that image.

Enumerated Values for Bit 2 Doppler Scale Type:

1

  Frequency

0

  Velocity

Valid for PW and CW regions only. Indicates which type of Doppler scale is used.

Enumerated Values for Bit 3-4 Scrolling Region:

00

  Unspecified

01

  Scrolling

10

  Sweeping

11

  Sweeping then Scrolling

Bit 5-31 Reserved for future use, shall be set to zero.

###### C.8.5.5.1.4 Pixel Component Organization

Pixel Component Organization (0018,6044) provides an Enumerated Value describing how the components of a pixel can be described. The absence of this data element means that pixel component calibration does not exist for this region.

Enumerated Values:

0

  Bit aligned positions

1

  Ranges

2

  Table look up

3

  Code Sequence look up

Other values reserved for future use.

Pixel Component Organization defines the way in which the composite pixel values are mapped into real world values with physical units, as illustrated in Figure C.8-7.

Figure C.8-7. Pixel Component Calibration

An example of Component Calibration for an ultrasound image is shown in Figure C.8-8.

Figure C.8-8. Pixel Component Calibration Example

In this example, some pixels lie within two Regions. One Region specifies pixel component calibration for Doppler velocity values. The second Region specifies pixel component calibration for Doppler magnitude. A particular Pixel Data (7FE0,0010) value will thus map to a displayed value, a Doppler velocity and magnitude value.

The example has a Palette Color Photometric Interpretation with 16 Bits Allocated and Bits Stored per sample. The Palette Color Lookup Tables also have 16 bits for each entry. The fact that the example has just one sample per pixel means that each composite pixel value is identical to the single Pixel Data value. An example Pixel Data value is shown in brackets along with the output values resulting from each step where it is processed.

The Pixel Data value is mapped to red, green, and blue values from the supplied Palette Color Lookup Tables before being displayed. The display device supports 8 bits per sample and thus requires the scaling of the output values from the 16 bit per entry LUTs.

The Doppler Velocity Region maps each pixel value in the Region to the Doppler velocity. The Pixel Component Organization (0018,6044) has a value of zero, indicating bit aligned positions with a bit mask. The Pixel Component Mask (0018,6046) specifies that the least significant 4 bits of the most significant byte convey the Doppler velocity of each pixel. The Pixel Component Physical Units (0018,604C) are cm/sec, and the Pixel Component Data Type (0018,604E) indicates color flow velocity. The Table of X Break Points (0018,6052) and Table of Y Break Points (0018,6054) map each masked composite pixel value to a Doppler velocity value in cm/sec.

The Doppler Magnitude Region maps each pixel value in the Region to the Doppler magnitude. The Pixel Component Organization (0018,6044) has a value of zero, indicating bit aligned positions with a bit mask. The Pixel Component Mask (0018,6046) specifies that the most significant 4 bits of the most significant byte convey the Doppler magnitude of each pixel. The Pixel Component Physical Units (0018,604C) is set to dB, and the Pixel Component Data Type (0018,604E) indicates color flow magnitude. The Table of X Break Points (0018,6052) and Table of Y Break Points (0018,6054) map each masked composite pixel value to a Doppler magnitude value in dB.

###### C.8.5.5.1.5 Pixel Component Mask

Pixel Component Mask (0018,6046) is ANDed with the Composite Pixel Code (see Section C.7.6.3.1.1) for each pixel within the region, then shifted right by the number of contiguous least significant zeros in the mask to obtain what will be referred to as the "Shifted Masked Composite Pixel Code".

The mask will most likely (but not necessarily) contain a block of contiguous ones, surrounded by leading and trailing zeros. The purpose of this mask is to keep only those bits within the composite pixel code that pertain to the region. It is to be used only when Pixel Organization is bit aligned positions.

###### C.8.5.5.1.6 Pixel Component Physical Units

Enumerated Values:

0000H

  None or not applicable

0001H

  Percent

0002H

  dB

0003H

  cm

0004H

  seconds

0005H

  hertz(seconds-1)

0006H

  dB/seconds

0007H

  cm/sec

0008H

  cm2

0009H

  cm2/sec

000AH

  cm3

000BH

  cm3/sec

000CH

  degrees

###### C.8.5.5.1.7 Pixel Component Data Type

Enumerated Values:

0000H

  None or not applicable

0001H

  Tissue

0002H

  Spectral Doppler

0003H

  Color Flow Velocity

0004H

  Color Flow Variance

0005H

  Color Flow Intensity

0006H

  Gray bar

0007H

  Color bar

0008H

  Integrated Backscatter

0009H

  Computed Border

000AH

  Tissue Classification

###### C.8.5.5.1.8 Number of Table Break Points

The Number of Table Break Points (0018,6050) gives the number of entries in each of two tables: the Table of X Break Points (0018,6052) and Table of Y Break Points (0018,6054). These tables are used to designate a curve mapping the value of a pixel component to its actual physical value, as described in Section C.8.5.5.1.9.

###### C.8.5.5.1.9 Table of X Break Points and Table of Y Break Points

Table of X Break Points (0018,6052) and Table of Y Break Points (0018,6054) are individual arrays of coordinates that interpreted together are used to create a piecewise linear curve. Each X value from the Table of X Break Points is matched with the corresponding Y value from the Table of Y Break Points yielding an (X,Y) coordinate. The set of (X,Y) coordinates describes a piecewise linear curve mapping the value of a pixel component to its actual physical value (in units defined in Pixel Component Physical Units data element (0018,604C)).

The X direction on the curve has no units, and represents actual pixel component values. If the Pixel Component Organization (0018,6044) is "Bit aligned positions", and the width of the Pixel Component Mask is n bits then the X coordinates are in the range 0 through 2n-1. If the Pixel Component Organization is Ranges, then the X coordinates are in the range 0 through 2 number of bits in the composite pixel- 1.

### Note

The X value is NOT relative to the Pixel Component Range Start (0018,6048). Not all possible X values in the range need be covered by the curve.

For any pixel component value in the range of the curve described by this table, the corresponding Y value is the actual physical value for that pixel, in units specified in Pixel Component Physical Units (0018,604C). If the pixel component value is NOT within the range of specified X values for the curve, then no pixel calibration is defined by this region. It may be possible for pixel calibration to be defined by other spatial regions intersecting this one.

###### C.8.5.5.1.10 TM-line Position X0, Y0, X1 and Y1

The TM-Line Position X0 (0018,603D) and TM-Line Position Y0 (0018,603F) are the coordinates of the starting point and TM-Line Position X1 (0018,6041), TM-Line Position Y1 (0018,6043) are the coordinates of the end point of the TM-line. The coordinate is defined as the displacement, in pixels, from the Reference pixel. Typically used for M-mode line and CW Doppler.

###### C.8.5.5.1.11 Number of Table Entries

The Number of Table Entries (0018,6056) gives the number of entries in the Table of Pixel Values, the number of entries in the Table of Parameter Values (0018,605A), if present, and the number of items in the Pixel Value Mapping Code Sequence (0040,9098), if present.

###### C.8.5.5.1.12 Table of Pixel Values

The Table of Pixel Values (0018,6058) specifies the pixel values that are mapped to real world parameter values or coded concepts (tissue characterizations). The number of entries in the table is given by Number of Table Entries (0018,6056).

A pixel is calibrated (mapped to a real-world value) by finding an entry in the Table of Pixel Values that matches its Composite Pixel Code (see Section C.7.6.3.1.1). The offset index of this entry is used as an index into the Parameter Value Table (0018,605A) or as a sequence item number in the Pixel Value Mapping Code Sequence (0040,9098) to select the real world value. The first Table of Pixel Values entry corresponds to sequence item 1.

### Note

If a Composite Pixel Code has no matching value in the Pixel Value Table then there is no unambiguous way to determine the corresponding Parameter Value. A method may exist to determine a valid Parameter Value but the specification of such a method is outside the scope of the DICOM standard. No assumption should be made that linear interpolation will produce a valid result.

###### C.8.5.5.1.13 Table of Parameter Values

The Table of Parameter Values (0018,605A) provides the real world values for pixel values identified in the Table of Pixel Values (0018,6058). The number of table entries is given by Number of Table Entries (0018,6056) and the physical units are given by Pixel Component Physical Units (0018,604C). Values may repeat when a parameter value is associated with more than one Composite Pixel Code value.

###### C.8.5.5.1.14 Region Location Min X0, Min Y0, Max X1 and Max Y1

These attributes specify the location of the region, Region Location Min X0 (0018,6018), Region Location Min Y0 (0018,601A), Region Location Max X1 (0018,601C), Region Location Max Y1 (0018,601E) expressed as offsets to the pixel coordinates. The upper left corner of the entire image is x=0,y=0 and the lower right corner is x=image width - 1, and y=image length - 1. Thus, a region will be specified as within these bounds. Where x0,y0 is the coordinate of the upper left corner of the region and x1,y1 is the coordinate of the lower right corner of the region.

###### C.8.5.5.1.15 Physical Units X Direction and Physical Units Y Direction

Physical Units X Direction (0018,6024) and Physical Units Y Direction (0018,6026) indicate the physical units of the dimensions of the region.

Enumerated Values:

0000H

  None or not applicable

0001H

  Percent

0002H

  dB

0003H

  cm

0004H

  seconds

0005H

  hertz(seconds-1)

0006H

  dB/seconds

0007H

  cm/sec

0008H

  cm2

0009H

  cm2/sec

000AH

  cm3

000BH

  cm3/sec

000CH

  degrees

###### C.8.5.5.1.16 Reference Pixel X0 and Reference Pixel Y0

This coordinate pair, Reference Pixel X0 (0018,6020), Reference Pixel Y0 (0018,6022) defines the location of a virtual "reference" pixel. This reference pixel location is used to tie the image's pixel coordinate system to the physical coordinate system. For example, the reference pixel could be defined where a depth of zero centimeters occurs in the 2D image, or it could define where the baseline (i.e.,: zero frequency) resides in a spectral display. The reference pixel location is the relative offset from the Region Location Min X0 (0018,6018) and Region Location Min Y0 (0018,601A), not the image origin. The location is not required to be within the region or even within the image boundary. For this reason, the Reference Pixel X0 and Reference Pixel Y0 values can be positive or negative.

The reference pixel location varies depending on the type and spatial organization of the data within the region.

###### C.8.5.5.1.16.1 2D - Tissue or Color Flow

Tissue data is tissue echo intensity displayed as grayscale. The Region Data Type (0018,6014) value is 0001H (Tissue). Color flow is Doppler signal displayed as color and encoded as some function of Doppler magnitude and velocity of blood flow or tissue motion. The Region Data Type value is 0002H (Color flow). For 2D, the Region Spatial Format (0018,6012) is 0001H (2D), meaning that the region is a tomographic image. For such 2D regions the reference pixel location is typically at the center of the transducer face on the tissue-transducer interface (skin line).

Figure C.8-1 shows 2D attribute values of reference pixel location along with Region Location Min and Region Location Max. for 2D-Tissue and 2D-Color Flow Regions:

Figure C.8-1. 2D Regions with Reference Pixel

Both the 2D regions-Tissue and Color Flow-share the same physical location at the skin line but the reference pixel location values (Reference Pixel X0 and Reference Pixel Y0) are relative to their respective region origins at the skin line.

###### C.8.5.5.1.16.2 Spectral - CW or PW Doppler or Doppler Trace

Spectral Doppler is the time varying magnitude of Doppler signal as function of frequency. Region Data Type (0018,6014) value is 0003H (pulsed wave Doppler) or 0004H (continuous wave Doppler). Spectral Doppler regions display the magnitude of Doppler signal with frequency or velocity as the vertical dimension and time as the horizontal dimension. Spectral Doppler regions have a Region Spatial Format (0018,6012) of 0003H (Spectral). The time dimension for the Region Spatial Format displays horizontally with data scrolling toward the left or sweeping toward the right. The reference pixel location is the pixel in the frame where:

- the time is the time of frame capture (i.e., the time origin for the frame)

- and on the Doppler Baseline (i.e., where the velocity and frequency are zero).

Figure C.8-2 shows an example of reference pixel locations in an image with both a Tissue and a scrolling Spectral (CW or PW Doppler) Region. The user adjusts the depth and position of the Doppler sample volume. The system annotates the sample volume position on the 2D region and specifies the location in Doppler Sample Volume X Position (0018,6039) and Doppler Sample Volume Y Position (0018,603B).

Figure C.8-2. 2D & Doppler Regions with Reference Pixel

The scrolling Spectral Region reference pixel location specifies the horizontal location at the time of the current image frame. Data to the left of this location in the Spectral Region was acquired in the past. Because time increases to the right, the Physical Delta X (0018,602C) for this Region is positive. To specify the location of the most recent data the Reference Pixel x0specifies the time of acquisition, and the Reference Pixel Physical Value X (0018,6028) specifies the reference time to be zero. The Physical Units X Direction (0018,6024) is seconds. For an explanation of how to handle sweeping regions refer to Section C.8.5.5.1.16.7 Treatment of Sweeping Regions.

The Reference Pixel Physical Value Y (0018,602A) value specifies the baseline where velocity or frequency are zero. Typically spectral Doppler regions display positive velocity (cm/Sec) or frequency shift (Hz) above the baseline. This indicates flow toward the transducer face. Negative velocity or frequency information is displayed below the baseline. This indicates flow away from the transducer face. The Physical Delta Y (0018,602E) value is therefore negative because vertical coordinates increment downward.

###### C.8.5.5.1.16.3 M-Mode - Tissue or Color Flow

M-Mode is tissue or color flow with a Region Spatial Format (0018,6012) of 0002H (M-mode). The vertical reference pixel location is the transducer face.

The horizontal reference pixel location is the pixel in the frame where:

- the time is the time of frame capture (i.e., the time origin for the frame)

- and zero depth from the transducer face

Figure C.8-3 shows an example of reference pixel locations for 2D Tissue and M-Mode Regions within the same image frame. The system annotates the sample line position on the 2D tissue region and specifies its position with the TM-Line Position attributes (0018,603D), (0018,603F), (0018,6041) and (0018,6043).

Figure C.8-3. 2D & M-Mode Regions with Reference Pixel Example

The physical length of the TM-Line corresponds directly to the physical height of the M-Mode Region. The M-Mode region's Reference Pixel y0 can be used to calculate the depth of the M-Mode region and facilitate depth measurements. In this example the M-Mode Region Reference Pixel y0 has a negative value corresponding to the distance between the face of the ultrasound probe and the TM-Line starting point. Note that the negative offset in pixel units is determined using the pixel height-width scaling of the M-Mode - Tissue Region as this could differ from the scaling of the 2D - Tissue Region (as it does in this example).

###### C.8.5.5.1.16.4 Waveform - ECG, Phonocardiogram and Pulse Traces

Waveforms are traces with a Region Spatial Format (0018,6012) value of 0004H (Waveform). The Reference Pixel x0 (0018,6020) specifies the time origin as the time of frame capture. There is typically no baseline position for ECG traces; the Reference Pixel y0 (0018,6022) is arbitrary.

Figure C.8-4 shows an example of reference pixel location for 2D Tissue, M-Mode, and ECG Waveform Regions within the same image frame:

Figure C.8-4. 2D, M-Mode, & Waveform Regions with Reference Pixel

###### C.8.5.5.1.16.5 Waveform - Doppler Mode, Mean and Max Trace

Doppler Traces have a Region Spatial Format (0018,6012) value of 0004H (Waveform) and a Region Data Type value of 0005H (Doppler Mean Trace), 0006H (Doppler Mode Trace) or 0007H (Doppler Max Trace). The Reference Pixel x0 (0018,6020) specifies the time origin as the time of frame capture. The Reference Pixel y0 (0018,6022) is the Doppler Baseline position (zero velocity / frequency position).

###### C.8.5.5.1.16.6 Graphics Spatial Formats

For regions with Region Spatial Format (0018,6012) value of 0005H (Graphics) the reference pixel location has no meaning.

###### C.8.5.5.1.16.7 Treatment of Sweeping Regions

Time-based display of data may scroll the acquired data from a fixed horizontal location to the left. Alternatively, sweep-based display increments the horizontal location of the acquired data, overwriting previously acquired data to the right. When the horizontal location corresponding to zero time has completely swept over the older data, writing wraps from the left of the region. Thus, sweep-based displays have a time discontinuity. The measurement of time intervals across the discontinuity requires special treatment. The time interval between two points across the discontinuity is equal to the region's time width minus the point separation. The sweeping area can be treated as a single region. The Reference Pixel x0 should indicate the time origin for the multi-frame image, which will be the location of the sweeping region's discontinuity line for the first frame of the multi-frame image. In order to specify that this is actually the location of the discontinuity line, the Reference Pixel Physical Value X (0018,6028) must be set to 0 seconds. This indicates that this location corresponds to the time at which the first frame was acquired.

It is useful to be able to calculate the location of the discontinuity line for subsequent frames of a multi-frame image. This is necessary if one is to determine whether two points are on opposite sides of the discontinuity line and also to correctly calculate the difference in time between such points. The x-axis location of the discontinuity line, x, for a given frame number, y, can be calculated from the Reference Pixel x0, x0, the Reference Pixel x1, x1, the time offset for frame y, t, (determined from the Frame Time Vector (0018,1065) or Frame Time (0018,1063)) and the Physical Delta X (0018,602C), px, as follows:

x = x0 + modulus((t / px) / (x1 - x0))

Alternatively, two regions can be used, one on each side of the time discontinuity. Figure C.8-5 shows the use of two regions. Note that the two region approach is not valid for multi-frame images, as the same region scaling must apply to all the frames.

Figure C.8-5. Sweep Example Using Two Regions

The two region approach may also be used in Doppler or physiological sweeping regions.

Time-based display of data may also be a combination of sweeping and scrolling. Sweep-based display is used at the start of acquisition, incrementing the horizontal location of the acquired data from left to right. After the horizontal location corresponding to zero time has completely swept to the right hand limit of the region, writing scrolls to the left from the right hand limit rather than wrapping from the left. A single region should be specified when this combination of behavior is used. The x-axis (zero time) location, x, for a given frame number, y, can be calculated from the Reference Pixel x0, x0, the Reference Pixel x1, x1, the time offset for frame y, t, (determined from the Frame Time Vector (0018,1065) or Frame Time (0018,1063)) and the Physical Delta X, px, as follows:

X = Min (x0 + (t / px), x1)

###### C.8.5.5.1.17 Physical Delta X and Physical Delta Y

The Physical Delta X (0018,602C) is the physical value increment per positive X pixel increment, which is left to right. The Physical Delta Y (0018,602E) is the physical value increment per positive Y pixel increment, which is top to bottom.

### Note

When displaying Doppler data, ultrasound applications typically display the Doppler strip horizontally, with data sweeping (moving time origin) from left (oldest) to right (newest) or scrolling (static time origin) from right to left. The default display of positive velocity values normally indicates flow toward the transducer; negative velocity values indicate flow away from the transducer. In this case a negative Physical Delta Y is required to specify that the direction of positive velocities or frequencies is upward.

###### C.8.5.5.1.18 Pixel Value Mapping Code Sequence

The Pixel Value Mapping Code Sequence (0040,9098) provides the real world values for pixel values identified in the Table of Pixel Values (0018,6058). The number of items in the sequence is given by Number of Table Entries (0018,6056).

### Note

Pixel Component Physical Units (0018,604C) does not apply to Sequence of Pixel Value Codes and should be set to 0000H (none or not applicable).

#### C.8.5.6 US Image Module

Table C.8-18 specifies the Attributes that describe ultrasound images.

Table C.8-18. US Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Samples Per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.8.5.6.1.12 for specialization
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.5.6.1.2 for specialization.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. See Section C.8.5.6.1.13 for specialization.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. See Section C.8.5.6.1.14 for specialization.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. See Section C.8.5.6.1.15 for specialization.
Planar Configuration | (0028,0006) | 1C | Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See Section C.8.5.6.1.16 for specialization.
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. See Section C.8.5.6.1.3 for specialization.
Frame Increment Pointer | (0028,0009) | 1C | Contains the Data Element Tag of the attribute that is used as the frame increment in Multi-frame pixel data (see Section C.7.6.6). Required if Number of Frames is sent. See Section C.8.5.6.1.4 for specialization.
Image Type | (0008,0008) | 2 | Image identification characteristics. See Section C.8.5.6.1.1 for specialization.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5 Required if Lossy Compression has been performed on the Image. May be present otherwise.
Number of Stages | (0008,2124) | 2C | Number of Stages in this protocol. Required if image was acquired in a Staged protocol.
Number of Views in Stage | (0008,212A) | 2C | Number of views in this Stage. Required if image was acquired in a Staged protocol.
R Wave Time Vector | (0018,6060) | 3 | The time offset(s) of the reported R Wave peaks, each relative to the time of the start of the acquisition of the first frame in msec. Multi-valued, with one value per reported R Wave.
Ultrasound Color Data Present | (0028,0014) | 3 | This element indicates if any ultrasound color data is present in an image. Enumerated Values: 00 Ultrasound color data not present in image 01 Ultrasound color data is present in image. See Section C.8.5.6.1.10
Stage Name | (0008,2120) | 3 | A Stage is a particular time slice of a protocol in which a set of images are collected. The names can be free form text. Recommended text for Stress Echo stage names: PRE-EXERCISE POST-EXERCISE PEAK-EXERCISE RECOVERY BASELINE LOW DOSE PEAK DOSE
Stage Code Sequence | (0040,000A) | 3 | Sequence of items describing the performed Ultrasound Protocol Stage(s). One or more Items are permitted in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 12002 “Ultrasound Protocol Stage Types”.
Stage Number | (0008,2122) | 3 | A number that identifies the Stage. Stage Number starts at one.
View Name | (0008,2127) | 3 | A View is a particular combination of the position and orientation when a set of images are acquired. Images are acquired at the same View in different Stages for the purpose of comparison.
View Number | (0008,2128) | 3 | A number that identifies the View. View Number starts at one.
Number of Event Timers | (0008,2129) | 3 | The number of event timers used at the time of acquisition of a Multi-frame image.
Event Elapsed Time(s) | (0008,2130) | 3 | An array of values associated with each event timer. Units in milliseconds.
Event Timer Name(s) | (0008,2132) | 3 | Name that identifies the event timer.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | For intravascular ultrasound, Defined CID 3010 “Cardiovascular Anatomic Locations” and Defined CID 3015 “Coronary Arteries” are specified for the Anatomic Region Sequence and Defined CID 3019 “Cardiovascular Anatomic Location Modifiers” is specified for the Anatomic Region Modifier Sequence. No other Context IDs are specified.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” | See Section C.8.5.6.1.19 for Context Group IDs.
Acquisition DateTime | (0008,002A) | 1C | The date and time that the acquisition of data that resulted in this image started. Required if Modality (0008,0060) = IVUS May be present otherwise. ### Note The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Trigger Time | (0018,1060) | 3 | Time interval measured in msec from the start of the R-wave to the beginning of data taking
Nominal Interval | (0018,1062) | 3 | Average R-R interval used for these data, in msec
Beat Rejection Flag | (0018,1080) | 3 | Beat length sorting has been applied. Enumerated Values: Y yes N no
Low R-R Value | (0018,1081) | 3 | R-R interval low limit for beat rejection, in msec
High R-R Value | (0018,1082) | 3 | R-R interval high limit for beat rejection, in msec
Heart Rate | (0018,1088) | 3 | Beats per minute.
IVUS Acquisition | (0018,3100) | 1C | Defined Terms: MOTOR_PULLBACK MANUAL_PULLBACK SELECTIVE GATED_PULLBACK See Section C.8.5.6.1.21 Required if Modality (0008,0060) = IVUS
IVUS Pullback Rate | (0018,3101) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK. Specified in units of mm/sec. See Section C.8.5.6.1.22
IVUS Gated Rate | (0018,3102) | 1C | Required if IVUS Acquisition (0018,3100) value is GATED_PULLBACK. Specified in units of mm/beat. See Section C.8.5.6.1.23
IVUS Pullback Start Frame Number | (0018,3103) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See Section C.8.5.6.1.24
IVUS Pullback Stop Frame Number | (0018,3104) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See Section C.8.5.6.1.25
Lesion Number | (0018,3105) | 3 | Identifier(s) of the lesion(s) of interest imaged within the current SOP Instance. Each lesion shall have a unique numeric integer identifier within the study. See Section C.8.5.6.1.26.
Output Power | (0018,5000) | 3 | Manufacturer defined character string description of ultrasound output level(s) used in generating a given image. Data may be expressed in dB, %, W/cm2, etc.
Transducer Data | (0018,5010) | 3 | Manufacturer defined code or description of ultrasound transducer used.
Transducer Type | (0018,6031) | 3 | Defined Terms: SECTOR_PHASED SECTOR_MECH SECTOR_ANNULAR LINEAR CURVED LINEAR SINGLE CRYSTAL SPLIT XTAL CWD IV_PHASED IV_ROT XTAL IV_ROT MIRROR ENDOCAV_PA ENDOCAV_MECH ENDOCAV_CLA ENDOCAV_AA ENDOCAV_LINEAR VECTOR_PHASED
Focus Depth | (0018,5012) | 3 | The depth, from the transducer face, of the manufacturer defined beam focus used for the image, in cm.
Processing Function | (0018,5020) | 3 | Manufacturer defined description of processing of echo information. Data may include code or description of gain (initial, overall, TGC, dynamic range, etc.), preprocessing, postprocessing, Doppler processing parameters, e.g., cutoff filters, etc., as used in generating a given image.
Mechanical Index | (0018,5022) | 3 | See Section C.8.5.6.1.8 for Description.
Bone Thermal Index | (0018,5024) | 3 | See Section C.8.5.6.1.8 for Description.
Cranial Thermal Index | (0018,5026) | 3 | See Section C.8.5.6.1.8 for Description.
Soft Tissue Thermal Index | (0018,5027) | 3 | See Section C.8.5.6.1.8 for Description.
Soft Tissue-focus Thermal Index | (0018,5028) | 3 | See Section C.8.5.6.1.8 for Description.
Soft Tissue-surface Thermal Index | (0018,5029) | 3 | See Section C.8.5.6.1.8 for Description.
Depth of Scan Field | (0018,5050) | 3 | The depth, in mm, from the transducer face to the deepest point included in the displayed image- the field of view.
Overlay Subtype | (60xx,0045) | 3 | Defined Term that identifies the intended purpose of the ROI Overlay Type. See Section C.8.5.6.1.11 for specialization.

### Note

Referenced Overlay Sequence (0008,1130) and Referenced Curve Sequence (0008,1145) were previously included in this Module as optional Attributes but have been retired. See PS3.3-2004.

##### C.8.5.6.1 US Image Attribute Descriptions

###### C.8.5.6.1.1 Image Type

For US Images, Image Type (0008,0008) is specified to be Type 2.

Defined Terms for Value 3:

ABDOMINAL

BREAST

CHEST

ENDOCAVITARY

ENDORECTAL

ENDOVAGINAL

EPICARDIAL

FETAL HEART

GYNECOLOGY

INTRACARDIAC

INTRAOPERATIVE

INTRAVASCULAR

MUSCULOSKELETAL

NEONATAL HEAD

OBSTETRICAL

OPHTHALMIC

PEDIATRIC

PELVIC

RETROPERITONEAL

SCROTAL

SMALL PARTS

TEE

THYROID

TRANSCRANIAL

TTE

US BIOPSY

VASCULAR

Value 4 is constructed as a modality bit map to allow for a description of multi-modality displays. In using this bit map, the sum of the values of the various modalities will unambiguously determine the constituent modalities.

Bit Map Values for Value 4:

0001

  2D Imaging

0002

  M-Mode

0004

  CW Doppler

0008

  PW Doppler

0010

  Color Doppler

0020

  Color M-Mode

0040

  3D Rendering

0100

  Color Power Mode

0200

  Tissue Characterization

0400

  Spatially-related frames

### Note

1. All Values are hexadecimal encoded as a CS. See PS3.5.

2. For example, Color Flow with CW spectral Doppler would have a value 4 = 0015. Note that no assumption should be made in Color Doppler or Color M-Mode regarding underlying B or M-Mode, respectively.

3. See Section A.59.1 for the relationship between a 3D volume set and the 3D Rendering, 3D MPR View, and Spatially-related frames image types. In the case of "3D Rendering", Derivation Code Sequence (0008,9215) should be used to describe the specific type of 3D rendering (volume rendering, surface rendering, multiplanar reformatting, etc.).

###### C.8.5.6.1.2 Photometric Interpretation

Defined Terms:

MONOCHROME2

PALETTE COLOR

RGB

ARGB

  (retired)

YBR_FULL

YBR_FULL_422

YBR_PARTIAL_422

YBR_RCT

YBR_ICT

YBR_PARTIAL_420

### Note

It is recommended that future implementations should not use ARGB photometric interpretation.

See PS3.5 for restrictions imposed by compressed Transfer Syntaxes.

###### C.8.5.6.1.3 Pixel Representation

For US Images, Pixel Representation (0028,0103) is specified to use the following.

Enumerated Values:

0000H

  unsigned integer

###### C.8.5.6.1.4 Frame Increment Pointer

For US Multi-frame images, the Attribute Frame Increment Pointer (0028,0009) of the Multi-frame Module (see Section C.7.6.6) is specified by the following.

Defined Terms:

00181063

  sequencing by Frame Time (0018,1063)

00181065

  sequencing by Frame Time Vector (0018,1065)

###### C.8.5.6.1.5 (Retired)

###### C.8.5.6.1.6 (Retired)

###### C.8.5.6.1.7 (Retired)

###### C.8.5.6.1.8 Mechanical Index, Bone Thermal Index, Cranial Thermal Index, Soft Tissue Thermal Index

The thermal and/or mechanical indices, when made available by a manufacturer, are defined according to the Standard for Real-Time Display of Thermal and Mechanical Acoustic Output Indices on Diagnostic Ultrasound Equipment, a voluntary performance standard jointly published by AIUM and NEMA.

###### C.8.5.6.1.9 Image Transformation Matrix and Image Translation Vector

This section was defined in a previous version of the DICOM Standard. The Section is now retired. See PS3.3-2003.

###### C.8.5.6.1.10 Ultrasound Color Data Present

### Note

This data element can be used to indicate if an image contains any Ultrasound color data.

For example: Some Ultrasound images may have a Photometric Interpretation equal to RGB but the image will have no color information if R=G=B for all pixels.

For consistency within a particular implementation Monochrome Ultrasound images may be coded using a color photometric interpretation. In that case inclusion of this data element can significantly speed up processing. Since all components are known to be equal only one need be handled. The enhancements can be significant when compressed Transfer Syntaxes are used.

###### C.8.5.6.1.11 Overlay Subtype

Defined Terms:

ACTIVE 2D/BMODE IMAGE AREA

  identification of the active area of a 2D/B-mode image

###### C.8.5.6.1.12 Samples Per Pixel

For US Images, Samples Per Pixel (0028,0002) is specified to use the following values for specific Photometric Interpretations:

Table C.8-19. US Samples Per Pixel

Photometric Interpretation | Samples Per Pixel Value
--- | ---
MONOCHROME2 | 1
RGB | 3
YBR_FULL | 3
YBR_FULL_422 | 3
YBR_PARTIAL_422 | 3
YBR_RCT | 3
YBR_ICT | 3
YBR_PARTIAL_420 | 3
PALETTE COLOR | 1

###### C.8.5.6.1.13 Bits Allocated

For US Images, Bits Allocated (0028,0100) is specified to use the following values for specific Photometric Interpretations:

Table C.8-20. US Bits Allocated

Photometric Interpretation | Bits Allocated Value
--- | ---
MONOCHROME2 | 8
RGB | 8
YBR_FULL | 8
YBR_FULL_422 | 8
YBR_PARTIAL_422 | 8
YBR_RCT | 8
YBR_ICT | 8
YBR_PARTIAL_420 | 8
PALETTE COLOR | 8 - 8 bit palette, or 16 - 16 bit palette

###### C.8.5.6.1.14 Bits Stored

For US Images, Bits Stored (0028,0101) is specified to use the following values for specific Photometric Interpretations:

Table C.8-21. US Bits Stored

Photometric Interpretation | Bits Stored Value
--- | ---
MONOCHROME2 | 8
RGB | 8
YBR_FULL | 8
YBR_FULL_422 | 8
YBR_PARTIAL_422 | 8
YBR_RCT | 8
YBR_ICT | 8
YBR_PARTIAL_420 | 8
PALETTE COLOR | 8 - 8 bit palette, or 16 - 16 bit palette

###### C.8.5.6.1.15 High Bit

For US Images, High Bit (0028,0102) is specified to use the following values for specific Photometric Interpretations:

Table C.8-22. US High Bit

Photometric Interpretation | High Bit Value
--- | ---
MONOCHROME2 | 7
RGB | 7
YBR_FULL | 7
YBR_FULL_422 | 7
YBR_PARTIAL_422 | 7
YBR_RCT | 7
YBR_ICT | 7
YBR_PARTIAL_420 | 7
PALETTE COLOR | 7 - 8 bit palette, or 15 - 16 bit palette

###### C.8.5.6.1.16 Planar Configuration

For US Images, Planar Configuration (0028,0006) is specified to use the following values for specific Photometric Interpretations:

Table C.8-23. US Planar Configuration

Photometric Interpretation | Planar Configuration Value
--- | ---
RGB | 0 - color-by-pixel, or 1 - color-by-plane
YBR_FULL | 1
YBR_FULL_422 | 0
YBR_PARTIAL_422 | 0
YBR_RCT | 0
YBR_ICT | 0
YBR_PARTIAL_420 | 0

###### C.8.5.6.1.19 View Code Sequence

The view of the patient anatomy may be described using coded terminology in the View Code Sequence (0054,0220). The view is typically specified by transducer position relative to the patient anatomy and/or transducer orientation,

The view may be described by a single Code Sequence Item, or by combination of post-coordinated Code Sequence Items. The principal coded item is specified in View Code Sequence, and modifier terms in the View Modifier Code Sequence (0054,0222). The Baseline CIDs for post-coordinated encoding of view are:

- CID 4 “Anatomic Region” (typically used for the primary coded item)

- CID 5 “Transducer Approach”

- CID 6 “Transducer Orientation”

- CID 7 “Ultrasound Beam Path”

Any of these Context Groups may be used in either the View Code Sequence or the View Modifier Code Sequence.

For cardiac imaging, a Baseline CID with pre-coordinated view codes is specified:

- CID 12226 “Echocardiography Image View”

### Note

Transducer Position Sequence (0008,2240) and Transducer Orientation Sequence (0008,2244), defined in this module in an earlier edition of the Standard (see PS3.3-2004), are retired.

###### C.8.5.6.1.20 (Retired)

###### C.8.5.6.1.21 IVUS Acquisition

Defined Terms:

MOTOR_PULLBACK

  The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is attached to a motorized mechanism capable of withdrawing the catheter through the vessel at a constant velocity specified by the attribute IVUS Pullback Rate (0018,3101) from the defined IVUS Pullback Start Frame Number (0018,3103) (see Section C.8.5.6.1.24) to the IVUS Pullback Stop Frame Number (0018,3104) (see Section C.8.5.6.1.25).

MANUAL_PULLBACK

  The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is manually withdrawn through the vessel region of interest.

SELECTIVE

  The IVUS imaging catheter is positioned in the blood vessel under examination near the anatomical structures to be examined. Then the catheter is manually withdrawn or advanced through the vessel region of interest.

GATED_PULLBACK

  The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is attached to a motorized mechanism capable of withdrawing the catheter through the vessel at a rate specified by the attribute IVUS Gated Rate (0018,3102), once per heart cycle, from the defined IVUS Pullback Start Frame Number (0018,3103) (see Section C.8.5.6.1.24) to the IVUS Pullback Stop Frame Number (0018,3104) (see Section C.8.5.6.1.25).

###### C.8.5.6.1.22 IVUS Pullback Rate

The attribute IVUS Pullback Rate (0018,3101) is required when IVUS Acquisition (0018,3100) is MOTOR_PULLBACK and it specifies the velocity of withdrawal of the IVUS imaging catheter in millimeters per second.

###### C.8.5.6.1.23 IVUS Gated Rate

The attribute IVUS Gated Rate (0018,3102) is required when IVUS Acquisition (0018,3100) is GATED_PULLBACK and it specifies the velocity of withdrawal of the IVUS imaging catheter in millimeters per beat.

###### C.8.5.6.1.24 IVUS Pullback Start Frame Number

The IVUS Pullback Start Frame Number (0018,3103) specifies the frame number of a IVUS multi-frame acquisition upon which motorized or gated pullback begins.

###### C.8.5.6.1.25 IVUS Pullback Stop Frame Number

The IVUS Pullback Stop Frame Number (0018,3104) specifies the frame number of a IVUS multi-frame acquisition upon which motorized or gated pullback ends.

###### C.8.5.6.1.26 Lesion Number

Attribute Lesion Number identifies the lesion(s) of interest imaged within the current SOP Instance. Each lesion shall have a unique numeric integer identifier within the study. If during a study the same lesion is imaged more than once, the same Lesion Number should be used for both SOP Instances.

### Note

1. Lesion Number is not a DICOM UID.

2. An IVUS pullback may contain multiple values in Lesion Number.

### C.8.6 Secondary Capture Modules

#### C.8.6.1 SC Equipment Module

This Module describes equipment used to convert images into a DICOM format.

Table C.8-24. SC Equipment Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Conversion Type | (0008,0064) | 1 | Describes the kind of image conversion. Defined Terms: DV Digitized Video DI Digital Interface DF Digitized Film WSD Workstation SD Scanned Document SI Scanned Image DRW Drawing SYN Synthetic Image
Modality | (0008,0060) | 3 | Source equipment for the image. This type definition shall override the definition in the General Series Module. See Section C.7.3.1.1.1 for Defined Terms.
Secondary Capture Device ID | (0018,1010) | 3 | User defined identification of the device that converted the image
Secondary Capture Device Manufacturer | (0018,1016) | 3 | Manufacturer of the Secondary Capture Device
Secondary Capture Device Manufacturer's Model Name | (0018,1018) | 3 | Manufacturer's model number of the Secondary Capture Device
Secondary Capture Device Software Versions | (0018,1019) | 3 | Manufacturer's designation of software version of the Secondary Capture Device
Video Image Format Acquired | (0018,1022) | 3 | Original format of the captured video image (e.g., NTSC, PAL, Videomed-H)
Digital Image Format Acquired | (0018,1023) | 3 | Additional information about digital interface used to acquire the image

### Note

1. The Attributes specified in the General Equipment Module (see Table C.7-6) describe the equipment that created the image being captured. The Attributes of the SC Equipment Module define the equipment that captured the image. The following table illustrates typical scenarios for different conversion types:

   Conversion Type (0008,0064) | General Equipment | Secondary Capture Equipment
   --- | --- | ---
   Digitized Video (DV) | The equipment generating the video signal. | The equipment digitizing the video signal.
   Digital Interface (DI) | The equipment on the sending side of the digital interface. | The equipment on the receiving side of the digital interface.
   Digitized Film (DF) | The equipment that created the film. | The equipment digitizing the film.
   Workstation (WSD) | Application dependent, but often the equipment that placed the image on the workstation screen, or created the modified image. | The equipment that captured the image from the screen, or placed the modified image into a DICOM SOP Instance.
   Scanned Document (SD) | The equipment that created the document. | The equipment digitizing the document.
   Scanned Image (SI) | The equipment that created the image that was digitized. | The equipment digitizing the image.
   Drawing (DRW) | The equipment that created the drawing. | The equipment digitizing (or rasterizing) the drawing.
   Synthetic Image (SYN) | The equipment creating the original images from which the synthetic image was derived. | The equipment creating the synthetic image.

2. Modality (0008,0060) specified in the General Series Module (see Table C.7-5a) has been specialized by this Module and is defined as a Type 3 Attribute.

#### C.8.6.2 SC Image Module

Table C.8-25 contains IOD Attributes that describe Secondary Capture Images.

Table C.8-25. SC Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Date of Secondary Capture | (0018,1012) | 3 | The date the Secondary Capture Image was captured.
Time of Secondary Capture | (0018,1014) | 3 | The time the Secondary Capture Image was captured.
Nominal Scanned Pixel Spacing | (0018,2010) | 3 | Physical distance on the media being digitized or scanned between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order. Shall be consistent with Pixel Aspect Ratio (0028,0034), if present.
Document Class Code Sequence | (0040,E008) | 3 | Classifications of a scanned document, e.g., for Modality (0008,0060) DOC. Equivalent to HL7 v2.x TXA-2. One or more items are permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined.
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |

### Note

The Attributes specified in the General Image Module (see Table C.7-7) describe this image (i.e., the secondary capture image). For example, Instance Number (0020,0013) is the image number of the secondary capture image. Source Image Sequence (0008,2112) may reference the DICOM image from which this image was generated.

#### C.8.6.3 SC Multi-frame Image Module

Table C.8-25b contains IOD Attributes that describe SC Multi-frame images.

Table C.8-25b. SC Multi-frame Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: YES NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Presentation LUT Shape | (2050,0020) | 1C | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY Output is in P-Values. Required if Photometric Interpretation (0028,0004) is MONOCHROME2, and Bits Stored (0028,0101) is greater than 1. ### Note If the VOI LUT Module is required by the IOD but no VOI LUT Sequence (0028,3010) or Window Center (0028,1050) is present, then the VOI LUT stage is an identity transformation.
Illumination | (2010,015E) | 3 | Luminance of a hypothetical viewing device illuminating a piece of monochrome transmissive film, or for the case of reflective media, luminance obtainable from diffuse reflection of the illumination present. Expressed as L0, in candelas per square meter (cd/m2). ### Note May be used together with Reflected Ambient Light (2010,0160) to recover Optical Density information from P-Values. See Section C.8.6.3.1.
Reflected Ambient Light | (2010,0160) | 3 | For scanned monochrome transmissive film viewed on a hypothetical viewing device, the luminance contribution due to reflected ambient light. Expressed as La, in candelas per square meter (cd/m2). ### Note May be used together with Illumination (2010,015E) to recover Optical Density information from P-Values. See Section C.8.6.3.1.
Rescale Intercept | (0028,1052) | 1C | The value b in the relationship between stored values (SV) in Pixel Data (7FE0,0010) and the output units specified in Rescale Type (0028,1054). Output units = m*SV + b. Required if Photometric Interpretation (0028,0004) is MONOCHROME2, and Bits Stored (0028,0101) is greater than 1. ### Note This specifies an identity Modality LUT transformation.
Rescale Slope | (0028,1053) | 1C | m in the equation specified by Rescale Intercept (0028,1052). Required if Photometric Interpretation (0028,0004) is MONOCHROME2, and Bits Stored (0028,0101) is greater than 1. ### Note This specifies an identity Modality LUT transformation.
Rescale Type | (0028,1054) | 1C | Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). Defined Terms: US Unspecified Required if Photometric Interpretation (0028,0004) is MONOCHROME2, and Bits Stored (0028,0101) is greater than 1. ### Note This specifies an identity Modality LUT transformation.
Frame Increment Pointer | (0028,0009) | 1C | Contains the Data Element Tag of the attribute that is used as the frame increment in Multi-frame pixel data. See Section C.7.6.6.1.2 for further explanation. Shall be present if Number of Frames is greater than 1, overriding (specializing) the Type 1 requirement on this attribute in the Multi-frame Module.
Nominal Scanned Pixel Spacing | (0018,2010) | 1C | Physical distance on the media being digitized or scanned between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order. Required if Conversion Type (0008,0064) is DF (Digitized Film). May also be present if Conversion Type (0008,0064) is SD (Scanned Document) or SI (Scanned Image). Shall be consistent with Pixel Aspect Ratio (0028,0034), if present.
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Digitizing Device Transport Direction | (0018,2020) | 3 | Enumerated Values: ROW COLUMN
Rotation of Scanned Film | (0018,2030) | 3 | Angle of the edge of the film relative to the transport direction in degrees greater than or equal to -45 and less than or equal to +45.

##### C.8.6.3.1 Scanned Film, Optical Density and P-Values

Illumination (2010,015E) and Reflected Ambient Light (2010,0160) may be used to recover Optical Density information from P-Values.

Monochrome media that is being digitized is often measured in Optical Density values. These values need to be converted to P-Values for storage and display. The P-Values used in an image correspond to the perception of a human observer viewing the film on a hypothetical viewing device (such as a light box), using the specified values of Illumination (2010,015E) and Reflected Ambient Light (2010,0160).

The Grayscale Standard Display Function defined in PS3.14 is used to convert Luminance to P-Values. In the case of scanned film, the Luminance is derived from Optical Density using the specified values of Illumination (2010,015E) and Reflected Ambient Light (2010,0160). An example of this derivation, as well as typical "default" values for these parameters, is specified in PS3.14.

#### C.8.6.4 SC Multi-frame Vector Module

Table C.8-25c contains IOD Attributes that may be the target of the Frame Increment Pointer (0028,0009) for SC Multi-frame images.

Table C.8-25c. SC Multi-frame Vector Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Time Vector | (0018,1065) | 1C | An array that contains the real time increments (in msec) between frames for a Multi-frame image. See Section C.7.6.5.1.2 for further explanation. Required if Frame Increment Pointer (0028,0009) points to Frame Time Vector (0018,1065). ### Note Frame Time Vector arrays may not be properly encoded if Explicit VR transfer syntax is used and the VL of this attribute exceeds 65534 bytes.
Page Number Vector | (0018,2001) | 1C | An array that contains, for each of the image frames, the corresponding page numbers of the original document. Required if Frame Increment Pointer (0028,0009) points to Page Number Vector (0018,2001).
Frame Label Vector | (0018,2002) | 1C | An array that contains, for each of the image frames, a descriptive label. Required if Frame Increment Pointer (0028,0009) points to Frame Label Vector (0018,2002).
Frame Primary Angle Vector | (0018,2003) | 1C | An array that contains, for each of the image frames, the primary angle of rotation about an undefined axis, in degrees. May be used for annotative purposes for "cine loops" of 3D reprojected images Required if Frame Increment Pointer (0028,0009) points to Frame Primary Angle Vector (0018,2003).
Frame Secondary Angle Vector | (0018,2004) | 1C | An array that contains, for each of the image frames, the secondary angle of rotation about an undefined axis that is orthogonal to that used for Frame Primary Angle Vector (0018,2003), in degrees. May be used for annotative purposes for "cine loops" of 3D reprojected images Required if Frame Increment Pointer (0028,0009) points to Frame Secondary Angle Vector (0018,2004).
Slice Location Vector | (0018,2005) | 1C | An array that contains, for each of the image frames, the relative position of the image plane expressed in mm, as defined for Slice Location (0020,1041). See Section C.7.6.2.1.2 for further explanation. Required if Frame Increment Pointer (0028,0009) points to Slice Location Vector (0018,2005).
Display Window Label Vector | (0018,2006) | 1C | An array that contains, for each of the image frames, a label or number of the display window of a graphical user interface from which the frame was captured. Required if Frame Increment Pointer (0028,0009) points to Display Window Label Vector (0018,2006).

### C.8.7 X-Ray Modules

This Section describes Modules used in one or more X-Ray IODs. These Modules contain Attributes that are specific to X-Ray images.

#### C.8.7.1 X-Ray Image Module

Table C.8-26. X-Ray Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Increment Pointer | (0028,0009) | 1C | Required if Multi-frame Image. Contains the Data Element Tag of the attribute that is used as the Frame increment in Multi-frame image pixel data (see Section C.7.6.6). Enumerated Values: 00181063H Frame Time (0018,1063) 00181065H Frame Time Vector (0018,1065)
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5 Required if Lossy Compression has been performed on the Image. May be present otherwise.
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.7.1.1.1 for specialization.
Pixel Intensity Relationship | (0028,1040) | 1 | The relationship between the Pixel sample values and the X-Ray beam intensity. See Section C.8.7.1.1.2.
Samples per Pixel | (0028,0002) | 1 | Number of samples (color planes) in this image shall have a value of 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Only MONOCHROME2 may be used.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. See Section C.8.7.1.1.6.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. See Section C.8.7.1.1.7.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. See Section C.8.7.1.1.8.
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Shall have the value: 0000H = Unsigned Integer.
Scan Options | (0018,0022) | 3 | Parameters of scanning sequence. See Section C.8.7.1.1.4.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | No Context ID for the Anatomic Region Sequence is defined.
R Wave Pointer | (0028,6040) | 3 | Marks the location(s) of the R Wave in the cardiac cycles by referencing frame numbers; frame numbers begin with 1.
Referenced Image Sequence | (0008,1140) | 1C | Other images significantly related to this image. Shall be present if Image Type (0008,0008) Value 3 is BIPLANE A or BIPLANE B. May be present otherwise. One or more items shall be included in this sequence. See Section C.8.7.1.1.13.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 3 | Describes the purpose for which the reference is made. Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7201 “Referenced Image Purposes of Reference”.
Derivation Description | (0008,2111) | 3 | A text description of how this image was derived. See Section C.8.7.1.1.5 for further explanation.
Acquisition Device Processing Description | (0018,1400) | 3 | Indicates any visual processing performed on the images prior to exchange. See Section C.8.7.1.1.3.
Frame Label Vector | (0018,2002) | 3 | A multi-valued attribute that contains a descriptive label for each of the image frames. The number of values shall equal the number of frames.
Frame Dimension Pointer | (0028,000A) | 3 | Contains the Data Element Tags of one or more attributes that vary or increment for the frames of a multi-frame image. See Section C.8.7.1.1.12. Shall not be present if it would contain only one value and that value would be Frame Time (0018,1063) or Frame Time Vector (0018,1065).
Calibration Image | (0050,0004) | 3 | Indicates whether a reference object (phantom) of known size is present in the image and was used for calibration. Enumerated Values: YES NO Device is identified using the Device module. See Section C.7.6.12.

##### C.8.7.1.1 X-Ray Image Attribute Descriptions

###### C.8.7.1.1.1 Image Type

The Image Type attribute identifies important image characteristics in a multiple valued data element. For X-Ray, Image Type is specialized as follows:

- Value 1 shall identify the Pixel Data Characteristics in accordance with Section C.7.6.1.1.2

  Enumerated Values:

  ORIGINAL

  DERIVED

  ### Note

  X-Ray images generally use PRIMARY value for images captured from patient exposure.

- Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2

  Enumerated Values:

  PRIMARY

  SECONDARY

- Value 3 shall identify the image set in terms of the imaging planes.

  Enumerated Values:

  SINGLE PLANE

    Image is a single plane acquisition

  BIPLANE A

    Image is the first plane (e.g., Frontal) of a Bi-plane acquisition

  BIPLANE B

    Image is the second plane (e.g., Lateral) of a Bi-plane acquisition

- Other Values are implementation specific (optional).

###### C.8.7.1.1.2 Pixel Intensity Relationship

Pixel Intensity Relationship (0028,1040) shall identify the relationship of the pixel values to the X-Ray beam intensity.

Defined Terms:

LIN

  Approximately proportional to X-Ray beam intensity;

LOG

  Non-linear "Log Function"; A Modality LUT shall be included with the image to allow it to be scaled back to its proportional value to X-Ray beam intensity;

DISP

  Ready to be displayed; A Modality LUT may be included with the image to allow it to be scaled back to its proportional value to X-Ray beam intensity. The Attribute Acquisition Device Processing Description may be used to provide some indication on the pre-processing performed to create the ready to be displayed image.

###### C.8.7.1.1.3 Acquisition Device Processing Description

Acquisition Device Processing Description (0018,1400) provides some indication in human readable text of the digital processing on the images before exchange. Examples of this processing are: edge enhanced, subtracted, time filtered, gamma corrected, convolved (spatially filtered).

###### C.8.7.1.1.4 Scan Options

The Scan Options attribute identifies any acquisition technique that was used during the acquisition of the image.

Defined Terms:

EKG

  EKG Event Trigger

PHY

  Physiological Event Trigger

TOMO

  Tomography

CHASE

  Bolus Chasing

ROTA

  Rotation

###### C.8.7.1.1.5 Derivation Description

If an Image is identified to be a Derived image (see Section C.8.7.1.1.1), Derivation Description (0008,2111) is an optional and implementation specific text description of the way the image was derived from an original image. As applied to X-Ray images, it may be used to describe derivation operations such as edge enhancement, temporal filtering, digital subtraction, or other linear and non-linear transformations.

###### C.8.7.1.1.6 Bits Allocated

Enumerated Values:

8

16

###### C.8.7.1.1.7 Bits Stored

Enumerated Values:

8

10

12

16

###### C.8.7.1.1.8 High Bit

For X-Ray Images, High Bit (0028,0102) shall be one less than the value in Bit Stored.

###### C.8.7.1.1.9 Synchronization of Frame and Waveform Times

The synchronization of a multi-frame X-Ray image with a waveform (e.g., ECG, pressure, or respiration) encoded in a different SOP Instance is managed through the attributes of the Synchronization Module (see Section C.7.4.2) of the Frame of Reference IE.

### Note

The use of a Curve IE within the X-Ray IODs was previously defined in DICOM (see PS3.3-2004). That use has been retired in favor of encoding waveform data in a separate IOD.

###### C.8.7.1.1.12 Frame Dimension Pointer

Frame Dimension Pointer (0028,000A) identifies attributes that vary or increment with each frame, and are clinically significant for viewing or processing the image. This is intended for SOP Instances whose preferred clinical presentation is dependent on frame relationships other than simply time.

Defined Terms for multi-frame cine from the Cine Module (see Section C.7.6.5) are:

00181063H

  Frame Time (0018,1063)

00181065H

  Frame Time Vector (0018,1065)

Defined Terms for rotational acquisition from the XA Positioner Module (see Section C.8.7.5) are:

00181520H

  Positioner Primary Angle Increment (0018,1520)

00181521H

  Positioner Secondary Angle Increment (0018,1521)

Defined Terms for stepped acquisition from the X-Ray Table Module (see Section C.8.7.4) are:

00181135H

  Table Vertical Increment (0018,1135)

00181137H

  Table Longitudinal Increment (0018,1137)

00181136H

  Table Lateral Increment (0018,1136)

Defined Terms for an arbitrary labeled increment:

00182002H

  Frame Label Vector (0018,2002)

### Note

1. Previous editions of the standard did not include the optional Frame Dimension Pointer (0028,000A), but instead depended entirely on the mandatory Frame Increment Pointer (0028,0009), and envisaged that only time and no other dimension would relate frames. Image creators that add the Frame Dimension Pointer (0028,000A) must anticipate that many implementations will ignore or discard this attribute when displaying or storing images and continue to assume that frames are temporally related.

2. Frame Time (0018,1063) or Frame Time Vector (0018,1065) will also be present and will contain appropriate values consistent with the times of acquisition of the frames.

###### C.8.7.1.1.13 Referenced Image Sequence

When Image Type (0008,0008) Value 3 is BIPLANE A or BIPLANE B, Referenced Image Sequence (0008,1140) shall be used to identify the corresponding SOP Instance of the Biplane acquisition. In this case, either:

- only a single item shall be present, or

- multiple items may be present, each with the Purpose of Reference Code Sequence (0040,A170) present, and only the first item having the Purpose of Reference value (121314, DCM, "Other image of biplane pair").

The Referenced Frame Number (0008,1160) attribute shall not be present in the Item that references the corresponding SOP Instance of the Biplane acquisition.

#### C.8.7.2 X-Ray Acquisition Module

Table C.8-27. X-Ray Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
KVP | (0018,0060) | 2 | Peak kilo voltage output of the X-Ray generator used.
Radiation Setting | (0018,1155) | 1 | Identify the general level of X-Ray dose exposure. Enumerated Values: SC low dose exposure generally corresponding to fluoroscopic settings (e.g., preparation for diagnostic quality image acquisition) GR high dose for diagnostic quality image acquisition (also called digital spot or cine)
X-Ray Tube Current | (0018,1151) | 2C | X-Ray Tube Current in mA. Required if Exposure (0018,1152) is not present. May be present otherwise.
X-Ray Tube Current in µA | (0018,8151) | 3 | X-Ray Tube Current in µA.
Exposure Time | (0018,1150) | 2C | Duration of X-Ray exposure in msec. See 8.7.2.1.1. Required if Exposure (0018,1152) is not present. May be present otherwise.
Exposure Time in µS | (0018,8150) | 3 | Duration of X-Ray exposure in µsec.
Exposure | (0018,1152) | 2C | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current. Required if either Exposure Time (0018,1150) or X-Ray Tube Current (0018,1151) are not present. May be present otherwise.
Exposure in mAs | (0018,9332) | 3 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Grid | (0018,1166) | 3 | Identify the grid. Only a single value shall be present. Defined Terms: IN A Grid is positioned; NONE No Grid is used.
Average Pulse Width | (0018,1154) | 3 | Average width of X-Ray pulse in msec.
Radiation Mode | (0018,115A) | 3 | Specifies X-Ray radiation mode. Defined Terms: CONTINUOUS PULSED
Type of Filters | (0018,1161) | 3 | Type of filter(s) inserted into the X-Ray beam (e.g., wedges).
Intensifier Size | (0018,1162) | 3 | Diameter of X-Ray intensifier in mm
Field of View Shape | (0018,1147) | 3 | Shape of the Image Intensifier Field of View. See Section C.8.7.2.1.2. Defined Terms: ROUND RECTANGLE
Field of View Dimension(s) | (0018,1149) | 3 | Dimensions of the Image Intensifier Field of View in mm. If Rectangle, row dimension followed by column; if Round, diameter.
Imager Pixel Spacing | (0018,1164) | 3 | Physical distance measured at the front plane of the Image Receptor housing between the center of each pixel specified by a numeric pair - row spacing value(delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. The value of this attribute shall never be adjusted to account for correction for the effect of geometric magnification or calibration against an object of known size; Pixel Spacing (0028,0030) is specified for that purpose.
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Focal Spot(s) | (0018,1190) | 3 | Nominal focal spot size in mm used to acquire this image.
Image and Fluoroscopy Area Dose Product | (0018,115E) | 3 | X-Ray dose, measured in dGy*cm*cm, to which the patient was exposed for the acquisition of this image plus any non-digitally recorded fluoroscopy that may have been performed to prepare for the acquisition of this image. ### Note The sum of the area dose product of all images of a Series or a Study may not result in the total area dose product to which the patient was exposed.

##### C.8.7.2.1 X-Ray Acquisition Attribute Descriptions

###### C.8.7.2.1.1 Exposure Time

Exposure time is the cumulative time the patient received X-Ray exposure during this image (Multi-frame image acquisition). Calculation is pulse width * number of frames.

###### C.8.7.2.1.2 Field of View

The Field of View Attribute describes the shape and dimensions of the Image Receptor Field of View, applicable to both Image Intensifier and Digital Detector. This could be further restricted by the Collimator. See Section C.8.7.3.

#### C.8.7.3 X-Ray Collimator

An X-Ray Collimator is a device placed close to the X-Ray Source to restrict the span of the X-Ray beam. It is often made of lead shutters. Figure C.8-9 presents in a graphical form its relationship with the Field Of View Dimensions (0018,1149).

Geometry of the collimator is specified with respect to a row and column coordinate system where the origin is the upper left hand pixel. This origin is specified by the values 1,1 for row/column. A row coordinate represent a number of raw spacing (vertical) and a column coordinate represents a column spacing (horizontal). Up to three different collimator shapes may be used and superimposed.

Figure C.8-9. Relationships of X-Ray Collimator

Table C.8-28. X-Ray Collimator Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Collimator Shape | (0018,1700) | 1 | Shape(s) of the collimator. Enumerated Values: RECTANGULAR CIRCULAR POLYGONAL This multi-valued Attribute shall contain at most one of each Enumerated Value.
Include Table C.8-28b “X-Ray Collimator Dimensions Macro Attributes” |

Table C.8-28b. X-Ray Collimator Dimensions Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Collimator Left Vertical Edge | (0018,1702) | 1C | Required if a value of Collimator Shape (0018,1700) is RECTANGULAR. Location of the left edge of the rectangular collimator with respect to pixels in the image given as column. See Section C.8.7.3.1.1.
Collimator Right Vertical Edge | (0018,1704) | 1C | Required if a value of Collimator Shape (0018,1700) is RECTANGULAR. Location of the right edge of the rectangular collimator with respect to pixels in the image given as column. See Section C.8.7.3.1.1.
Collimator Upper Horizontal Edge | (0018,1706) | 1C | Required if a value of Collimator Shape (0018,1700) is RECTANGULAR. Location of the upper edge of the rectangular collimator with respect to pixels in the image given as row. See Section C.8.7.3.1.1.
Collimator Lower Horizontal Edge | (0018,1708) | 1C | Required if a value of Collimator Shape (0018,1700) is RECTANGULAR. Location of the lower edge of the rectangular collimator with respect to pixels in the image given as row. See Section C.8.7.3.1.1.
Center of Circular Collimator | (0018,1710) | 1C | Required if a value of Collimator Shape (0018,1700) is CIRCULAR. Location of the center of the circular collimator with respect to pixels in the image given as row and column. See Section C.8.7.3.1.1.
Radius of Circular Collimator | (0018,1712) | 1C | Required if a value of Collimator Shape (0018,1700) is CIRCULAR. Radius of the circular collimator with respect to pixels in the image given as a number of pixels along the row direction. See Section C.8.7.3.1.1.
Vertices of the Polygonal Collimator | (0018,1720) | 1C | Required if a value of Collimator Shape (0018,1700) is POLYGONAL. Multiple Values where the first set of two values are: row of the origin vertex; column of the origin vertex. Two or more pairs of values follow and are the row and column coordinates of the other vertices of the polygon collimator. Polygon collimators are implicitly closed from the last vertex to the origin vertex and all edges shall be non-intersecting except at the vertices.

##### C.8.7.3.1 X-Ray Collimator Attribute Descriptions

###### C.8.7.3.1.1 Collimator Vertical and Horizontal Edges

These attributes specify the pixel row or column where the X-Ray beam is fully obscured by a rectangular collimator:

- if the left edge of the collimator is not visible, Collimator Left Vertical Edge (0018,1702) shall have a value of 0;

- if the right edge of the collimator is not visible, Collimator Right Vertical Edge (0018,1704) value shall be 1 greater than the value of Columns (0028,0011) attribute;

- if the top edge of the collimator is not visible, Collimator Upper Horizontal Edge (0018,1706) shall have a value of 0;

- if the bottom edge of the collimator is not visible, Collimator Lower Horizontal Edge (0018,1708) value shall be 1 greater than the value of Rows (0028,0010) attribute.

#### C.8.7.4 X-Ray Table Module

Table C.8-29 contains Attributes that describe X-Ray images acquired with movement of the patient imaging table.

Table C.8-29. X-Ray Table Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Table Motion | (0018,1134) | 2 | Defined Terms: STATIC DYNAMIC
Table Vertical Increment | (0018,1135) | 2C | Incremental change in Vertical position of the table relative to first frame of Multi-frame image given in mm. Required if Table Motion is DYNAMIC.
Table Longitudinal Increment | (0018,1137) | 2C | Incremental change in Longitudinal position of the table relative to first frame of Multi-frame image in mm. Table motion towards +90°position of the primary angle of the positioner is positive. See Section C.8.7.4.1.2. Required if Table Motion is DYNAMIC.
Table Lateral Increment | (0018,1136) | 2C | Incremental change in Lateral position of the table relative to first frame of Multi-frame image given in mm. Table motion towards +90°position of the secondary angle of the positioner is positive. See Section C.8.7.4.1.3. Required if Table Motion is DYNAMIC.
Table Angle | (0018,1138) | 3 | Angle of table plane in degrees relative to horizontal plane [Gravity plane]. Positive values indicate that the head of the table is upwards.

##### C.8.7.4.1 X-Ray Table Attribute Descriptions

###### C.8.7.4.1.1 Table Motion Increments

This section is replaced by Section C.8.7.4.1.4

###### C.8.7.4.1.2 Table Longitudinal Increment

The direction of the longitudinal movement is perpendicular to the primary axis of rotation of the positioner. A positive value of Table Longitudinal Increment (0018,1137) attributes indicates a movement towards the +90° position of the positioner, see Figure C.8-9a.

Figure C.8-9a. Table Longitudinal Movement

###### C.8.7.4.1.3 Table Lateral Increment

The direction of the lateral movement is perpendicular to the secondary axis of rotation of the positioner. A positive value of Table Lateral Increment (0018,1136) attributes indicates a movement towards the +90° position of the positioner, see Figure C.8-9b.

Figure C.8-9b. Table Lateral Movement

### Note

The terms "longitudinal" and "lateral" are relative to an operator standing tableside, and facing the patient. Thus lateral movement is to the left and right of the operator, and longitudinal movement is towards or away from the operator.

###### C.8.7.4.1.4 Table Motion With Patient in Relation to Imaging Chain

The table moves the Patient with respect to the imaging chain. This is being tracked as a motion of the imaging chain with respect to a coordinate system (X, Y, Z) attached to the patient (assumption is that the patient does not move with respect to the table). The coordinate system origin is fixed with respect to the patient at the time of the first frame. The X-axis is increasing to the left hand side of the patient. The Y-axis is increasing to the posterior side of the patient. The Z-axis is increasing toward the head of the patient (see Section C.7.6.2.1.1). The Patient Plane is then defined by the X and Z-axes as drawn in Figure C.8-10).

### Note

1. Table motion causes the apparent locus of imaging to move in the opposite direction. For instance, with the patient supine and the table motion towards +90°of the primary axis of rotation of the positioner, the area of the patient imaged moves toward the right hand side of the patient.

2. When the patient is positioned prone or supine (Figure C.8-2 showing the supine position) the Table Longitudinal Increment (0018,1137) table motion takes place along the patient X-axis and the Table Lateral Increment (0018,0036) along the Z-axis. For patient positioned left or right decubitus, the Table Longitudinal Increment takes place along the Y-axis, the other direction is not changed.

Figure C.8-10. Table Motion Vector Coordinates

#### C.8.7.5 XA Positioner Module

Table C.8-30 contains IOD Attributes that describe a c-arm positioner typically used in acquiring X-Ray Angiographic Images. The coordinate system used to track the positioner is defined in reference to the patient. The definition of coordinates with respect to the equipment is not supported. Furthermore, this module does not describe the movement of the Patient.

### Note

The scope of the XA IOD is to address images produced on acquisition equipment equipped with an X-Ray source and an image Receptor positioned by what is general called a c-arm. For clinical areas other than Angiography that are using a c-arm to position the X-Ray source and image receptor (e.g., Interventional Procedures and Myelography and Biopsy/Localization), the X-Ray Angiography Image Object should be also used. Although the object is optimized for c-arm systems, it may also be used by other systems that support a similar coordinate system, such as some RF systems.

Table C.8-30. XA Positioner Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to center of field of view. ### Note This value is traditionally referred to as Source Object Distance (SOD). For cardiovascular image equipment the SOD value typically is the distance from source to isocenter.
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
Estimated Radiographic Magnification Factor | (0018,1114) | 3 | Ratio of Source Image Receptor Distance (SID) over Source Object Distance (SOD).
Positioner Motion | (0018,1500) | 2C | Used to describe the activity of the imaging devices. Defined Terms: DYNAMIC STATIC See Section C.8.7.5.1.1. Required if Pixel Data (7FE0,0010) contains more than one frame. May be present otherwise.
Positioner Primary Angle | (0018,1510) | 2 | Position of the X-Ray Image Intensifier about the patient from the RAO to LAO direction where movement from RAO to vertical is positive. See Section C.8.7.5.1.2.
Positioner Secondary Angle | (0018,1511) | 2 | Position of the X-Ray Image Intensifier about the patient from the CAU to CRA direction where movement from CAU to vertical is positive. See Section C.8.7.5.1.2
Positioner Primary Angle Increment | (0018,1520) | 2C | Incremental change in primary positioner angle for each frame. See Section C.8.7.5.1.3. Required if Positioner Motion (0018,1500) equals DYNAMIC.
Positioner Secondary Angle Increment | (0018,1521) | 2C | Incremental change in secondary positioner angle for each frame. See Section C.8.7.5.1.3. Required if Positioner Motion (0018,1500) equals DYNAMIC.
Detector Primary Angle | (0018,1530) | 3 | Angle of the X-Ray beam in the row direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted towards higher numbered columns. Negative values indicate that the X-Ray beam is tilted towards lower numbered columns. See Section C.8.7.5.1.4.
Detector Secondary Angle | (0018,1531) | 3 | Angle of the X-Ray beam in the column direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted towards lower numbered rows. Negative values indicate that the X-Ray beam is tilted towards higher numbered rows. See Section C.8.7.5.1.4.

##### C.8.7.5.1 XA Positioner Attribute Descriptions

###### C.8.7.5.1.1 Positioner Motion

Positioner Motion (0018,1500) attribute is STATIC if the imaging table moves during a multi-frame acquisition, but the X-Ray positioner do not move.

If Pixel Data (7FE0,0010) contains a single frame and a value of Positioner Motion (0018,1500) is provided, the value shall be STATIC.

### Note

If the positioner undergoes translation (non-rotational movement) during the acquisition, then that motion shall be described by an opposite table motion (see Section C.8.7.4).

###### C.8.7.5.1.2 Positioner Primary and Secondary Angles

The definitions of Positioner Angles shall be with respect to the patient as illustrated in Figure C.8-11 and Figure C.8-12. Zero degree is referenced to the origin perpendicular to the patient's chest. The Positioner Primary Angle definition is like longitude (in the equatorial plan); the Positioner Secondary Angle definition is like latitude (in the sagittal plane). The Positioner Angle attributes apply to the first frame of a multi-frame image. The valid range of Primary Positioner Angle is -180 to +180 degrees and the Secondary Positioner Angle range is -90 to + 90 degrees.

The Patient Plane is defined by the isocenter of the imaging device and slices through the patient such that it is perpendicular to the sagittal plane of the body. The Primary Axis of rotation is defined at the intersection of the Patient Plane and of the Sagittal Plane. The Positioner Primary Angle is defined in the transaxial plane at the isocenter with zero degrees in the direction perpendicular to the patient's chest and + 90 degrees at the Patient left hand side (LAO) and -90 at the Patient right hand side (RAO). The valid range of Primary Positioner Angle is -180 to +180 degrees.

The Secondary Axis is in the Patient Plane and is perpendicular to the Primary Axis at the isocenter. The Positioner Secondary Angle is defined in the Sagittal Plane at the isocenter with zero degrees in the direction perpendicular to the patient's chest. +90 degrees corresponds to the cranial direction. The Secondary Positioner Angle range is -90 to + 90 degrees.

At a 0 angle for both Primary Angle (0018,1510) and Secondary Angle (0018,1511), the patient faces the Image Intensifier.

The Positioner Primary Angle (0018,1510) and Secondary Angle (0018,1511) apply to the first frame of a multi-frame image.

Figure C.8-11. Positioner Primary Angle

Figure C.8-12. Positioner Secondary Angle

###### C.8.7.5.1.3 Positioner Angle Increments

If the positioner angles change during acquisition of a multi-frame image, the Positioner Angle Increment attributes describe the angular change per frame.

If the change in positioner angle is nominally constant for each frame, these fields may contain a single value of the average angular change per frame. Alternatively, the fields may contain a vector of offsets from the (initial) Positioner Angle attributes, with one value for each frame in the multi-frame image. The number of values in the Positioner Angle Increment attributes must be one, or must be equal to Number of Frames (0028,0008) in the Multi-frame Module (see Section C.7.6.6).

### Note

It is permissible to generate a vector of the absolute positioner angles in the Positioner Angle Increment attributes, and set the Positioner Primary and Secondary Angle attributes to value 0.

###### C.8.7.5.1.4 Detector Primary and Secondary Angles

Detector Angles are defined in a fashion similar to the positioner angles, except that the angle of the central x-ray beam vector is relative to the detector plane rather than the patient plane. The central x-ray beam vector is defined as the vector from the x-ray source through the isocenter to the detector plane. Zero degree is referenced to the normal to the detector plane pointing away from the x-ray source. The Detector Angle attributes apply to the first frame of a multi-frame image. The valid range of the Detector Angles is -90 to + 90 degrees.

The Primary Axis of rotation is defined along the line in the column direction of the detector plane that intersects the central x-ray beam vector. The Detector Primary Angle is defined in the plane perpendicular to the Primary Axis of rotation at the point where the central x-ray beam vector intersects the detector plane, with zero degrees in the direction normal to the detector plane and -90 degrees at the left hand side of the image (i.e., toward column 1) and +90 at the right hand side of the image (i.e., toward the highest numbered column). The valid range of Primary Detector Angle is -90 to +90 degrees.

The Secondary Axis is in the detector plane and is perpendicular to the Primary Axis at the intersection of the beam vector with the detector plane (i.e., it is along the row direction). The Detector Secondary Angle is defined in the plane perpendicular to the Secondary Axis at the point where the central x-ray beam vector intersects the detector plane, with zero degrees in the direction normal to the detector plane. +90 degrees corresponds to the direction toward the top of the image. The Secondary Detector Angle range is -90 to + 90 degrees.

#### C.8.7.6 XRF Positioner Module

Table C.8-31. XRF Positioner Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to center of field of view. ### Note This value is traditionally referred to as Source Object Distance (SOD).
Estimated Radiographic Magnification Factor | (0018,1114) | 3 | Ratio of SID (Source Image Receptor Distance) over SOD (Source Object Distance).
Column Angulation | (0018,1450) | 3 | Angle of the X-Ray beam in degree relative to an orthogonal axis to the detector plane. Positive values indicate that the tilt is towards the head of the table. ### Note The detector plane is assumed to be parallel to the table plane.

#### C.8.7.7 X-Ray Tomography Acquisition Module

This Module describes the attributes of a Tomography acquisition (translation of X-Ray source during the acquisition of a single frame image).

Table C.8-32. X-Ray Tomography Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Tomo Layer Height | (0018,1460) | 1 | Distance in mm between the table surface and the sharp image plane.
Tomo Angle | (0018,1470) | 3 | Angle span in degrees of rotation of X-Ray Source during X-Ray acquisition.
Tomo Time | (0018,1480) | 3 | Time in seconds the source has taken to rotate the Tomo Angle during X-Ray acquisition.
Tomo Type | (0018,1490) | 3 | Type of tomography. Defined Terms: LINEAR SPIRAL POLYCYCLOIDAL CIRCULAR
Tomo Class | (0018,1491) | 3 | Form of tomography: Defined Terms: MOTION TOMOSYNTHESIS
Number of Tomosynthesis Source Images | (0018,1495) | 3 | The number of source images used to construct this tomosynthetic image. Only meaningful if Tomo Class (0018,1491) is TOMOSYNTHESIS. These may be listed in Source Image Sequence (0008,2112) of the General Image Module.

#### C.8.7.8 X-Ray Acquisition Dose Module

This Module describes the attributes related to dose delivery from an X-Ray source during the acquisition of an X-Ray image.

Table C.8-33. X-Ray Acquisition Dose Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
KVP | (0018,0060) | 3 | Peak kilo voltage output of the X-Ray generator used.
X-Ray Tube Current | (0018,1151) | 3 | X-Ray Tube Current in mA.
X-Ray Tube Current in µA | (0018,8151) | 3 | X-Ray Tube Current in µA.
Exposure Time | (0018,1150) | 3 | Duration of X-Ray exposure in msec.
Exposure Time in µS | (0018,8150) | 3 | Duration of X-Ray exposure in µsec.
Exposure | (0018,1152) | 3 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure in µAs | (0018,1153) | 3 | The exposure expressed in µAs, for example calculated from Exposure Time and X-Ray Tube Current.
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to the table, support or bucky side that is closest to the Imaging Subject, as measured along the central ray of the X-Ray beam. ### Note This definition is less useful in terms of estimating geometric magnification than a measurement to a defined point within the Imaging Subject, but accounts for what is realistically measurable in an automated fashion in a clinical setting. This measurement does not take into account any air gap between the Imaging Subject and the "front" of the table or bucky. If the detector is not mounted in a table or bucky, then the actual position relative to the patient is implementation or operator defined. This value is traditionally referred to as Source Object Distance (SOD).
Image and Fluoroscopy Area Dose Product | (0018,115E) | 3 | X-Ray dose, measured in dGy*cm*cm, to which the patient was exposed for the acquisition of this image plus any non-digitally recorded fluoroscopy that may have been performed to prepare for the acquisition of this image. ### Note The sum of the area dose product of all images of a Series or a Study may not result in the total area dose product to which the patient was exposed. This may be an estimated value based on assumptions about the patient's body size and habitus.
Body Part Thickness | (0018,11A0) | 3 | The average thickness in mm of the body part examined when compressed, if compression has been applied during exposure.
Relative X-Ray Exposure | (0018,1405) | 3 | Indication of the applied dose, in manufacturer specific units. ### Note This value is intended to provide a single location where manufacturer specific information can be found for annotation on a display or film, that has meaning to a knowledgeable observer. This may be a calculated or measured value. Examples are the detector entrance dose (KB), the CR sensitivity value (S), or the logarithmic median (lgM). DICOM specifies standard Attributes in Table 10-23 'Exposure Index Macro', which are recommended.
Entrance Dose | (0040,0302) | 3 | Average entrance dose value measured in dGy at the surface of the patient during the acquisition of this image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
Entrance Dose in mGy | (0040,8302) | 3 | Average entrance dose value measured in mGy at the surface of the patient during the acquisition of this image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
Exposed Area | (0040,0303) | 3 | Typical dimension of the exposed area at the detector plane. If Rectangular: row dimension followed by column; if Round: diameter. Measured in cm. ### Note The exposed area should be consistent with values specified in the X-Ray Collimator Module, if present. This may be an estimated value based on assumptions about the patient's body size and habitus. This attribute is used in the Radiation Dose Module with units in mm (see Section C.4.16, Table C.4-16 “Radiation Dose Module Attributes”).
Distance Source to Entrance | (0040,0306) | 3 | Distance in mm from the source to the surface of the patient closest to the source during the acquisition of this image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
Comments on Radiation Dose | (0040,0310) | 3 | User-defined comments on any special conditions related to radiation dose encountered during the acquisition of this image.
X-Ray Output | (0040,0312) | 3 | The X-Ray output at the patient entrance surface and kVp used to acquire the image, measured in mGy/mAs. ### Note This value may be a calibrated value rather than measured during the exposure.
Half Value Layer | (0040,0314) | 3 | The thickness of Aluminum in mm required to reduce the X-Ray Output (0040,0312) by a factor of two. ### Note This value may be a calibrated value rather than measured during the exposure.
Organ Dose | (0040,0316) | 3 | Average organ dose value measured in dGy during the acquisition of this image. ### Note This may be an estimated value.
Organ Exposed | (0040,0318) | 3 | Organ to which Organ Dose (0040,0316) applies. Defined Terms: BREAST GONADS BONE MARROW FETUS LENS ### Note The anatomic regions described by these terms are those that are particularly radiosensitive and for which it is conventional to obtain organ specific dose parameters.
Anode Target Material | (0018,1191) | 3 | The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
Include Table C.8-35a “X-Ray Filtration Macro Attributes” |
Rectification Type | (0018,1156) | 3 | Type of rectification used in the X-Ray generator. Defined Terms: SINGLE PHASE THREE PHASE CONST POTENTIAL
Include Table 10-23 “Exposure Index Macro Attributes” |

#### C.8.7.9 X-Ray Generation Module

This Module describes the attributes related to generation of X-Rays during the acquisition of an X-Ray image.

Table C.8-34. X-Ray Generation Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
KVP | (0018,0060) | 3 | Peak kilo voltage output of the X-Ray generator used.
X-Ray Tube Current | (0018,1151) | 3 | X-Ray Tube Current in mA.
X-Ray Tube Current in µA | (0018,8151) | 3 | X-Ray Tube Current in µA.
Exposure Time | (0018,1150) | 3 | Duration of X-Ray exposure in msec.
Exposure Time in µS | (0018,8150) | 3 | Duration of X-Ray exposure in µsec.
Exposure | (0018,1152) | 3 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure in µAs | (0018,1153) | 3 | The exposure expressed in µAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure Control Mode | (0018,7060) | 3 | Type of exposure control. Defined Terms: MANUAL AUTOMATIC
Exposure Control Mode Description | (0018,7062) | 3 | Text description of the mechanism of exposure control. May describe the number and type of exposure sensors or position of the sensitive area of the imaging detector.
Exposure Status | (0018,7064) | 3 | Whether the exposure was normally completed or not. Defined Terms: NORMAL ABORTED
Phototimer Setting | (0018,7065) | 3 | Nominal percentage phototimer setting, where a more positive value indicates greater exposure and a more negative value indicates less exposure.
Focal Spot(s) | (0018,1190) | 3 | Nominal focal spot size in mm used to acquire this image.
Anode Target Material | (0018,1191) | 3 | The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
Rectification Type | (0018,1156) | 3 | Type of rectification used in the X-Ray generator. Defined Terms: SINGLE PHASE THREE PHASE CONST POTENTIAL
Generator ID | (0018,1005) | 3 | Identifier of the generator

#### C.8.7.10 X-Ray Filtration Module

This Module describes the attributes related to the filtration of X-Rays during the acquisition of an X-Ray image.

Table C.8-35. X-Ray Filtration Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table C.8-35a “X-Ray Filtration Macro Attributes” |

Table C.8-35a. X-Ray Filtration Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Filter Type | (0018,1160) | 3 | Type of filter(s) inserted into the X-Ray beam (e.g., wedges). Defined Terms: STRIP WEDGE BUTTERFLY MULTIPLE NONE ### Note Multiple type of filters can be expressed by a combination, e.g., BUTTERFLY+WEDGE.
Filter Material | (0018,7050) | 3 | The X-Ray absorbing material used in the filter. May be multi-valued. Defined Terms: MOLYBDENUM ALUMINUM COPPER RHODIUM NIOBIUM EUROPIUM LEAD
Filter Thickness Minimum | (0018,7052) | 3 | The minimum thickness in mm of the X-Ray absorbing material used in the filters. May be multi-valued, with values corresponding to the respective values in Filter Material (0018,7050).
Filter Thickness Maximum | (0018,7054) | 3 | The maximum thickness in mm of the X-Ray absorbing material used in the filters. May be multi-valued, with values corresponding to the respective values in Filter Material (0018,7050).
Filter Beam Path Length Minimum | (0018,7056) | 3 | The minimum length (in mm) of the X-Ray beam path in the Filter Material that is not blocked by collimation. May be multi-valued, with values corresponding to the respective values in Filter Material (0018,7050).
Filter Beam Path Length Maximum | (0018,7058) | 3 | The maximum length (in mm) of the X-Ray beam path in the Filter Material that is not blocked by collimation. May be multi-valued, with values corresponding to the respective values in Filter Material (0018,7050).

#### C.8.7.11 X-Ray Grid Module

This Module describes the attributes related to the use of a grid to reduce scatter of X-Rays during the acquisition of an X-Ray image.

Table C.8-36. X-Ray Grid Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Grid | (0018,1166) | 3 | Identifies the grid. May be multi-valued. Defined Terms: FIXED FOCUSED RECIPROCATING PARALLEL CROSSED NONE
Include Table C.8-36b “X-Ray Grid Description Macro Attributes” |

Table C.8-36b. X-Ray Grid Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Grid Absorbing Material | (0018,7040) | 3 | The X-Ray absorbing material used in the grid.
Grid Spacing Material | (0018,7041) | 3 | The spacing material used in the grid.
Grid Thickness | (0018,7042) | 3 | The thickness in mm of the X-Ray absorbing material used in the grid.
Grid Pitch | (0018,7044) | 3 | The pitch in mm of the X-Ray absorbing material used in the grid.
Grid Aspect Ratio | (0018,7046) | 3 | Ratio of the vertical spacing and horizontal spacing of the X-Ray absorbing material used in the grid. Specified by a pair of integer values where the first value is the vertical size, and the second value is the horizontal size.
Grid Period | (0018,7048) | 3 | Period in mSec of reciprocation cycle. Only meaningful if a value of Grid (0018,1166) is RECIPROCATING.
Grid Focal Distance | (0018,704C) | 3 | Focal distance in mm of a FOCUSED grid.
Grid ID | (0018,1006) | 3 | Identifier of the grid

### C.8.8 Radiotherapy Modules

This Section describes Radiotherapy-specific modules.

Modules defined here make reference to "IEC" coordinate systems and standards. These standards are defined in IEC Standard 61217, "Radiotherapy Equipment - Coordinates, Movements and Scales" (Reference CEI/IEC 61217: 1996).

### Note

IEC document 62C/269/CDV "Amendment to IEC 61217: Radiotherapy Equipment - Coordinates, movements and scales" also defines a patient-based coordinate system, and specifies the relationship between the DICOM Patient Coordinate System (see Section C.7.6.2.1.1) and the IEC PATIENT Coordinate System. Rotating the IEC PATIENT Coordinate System described in IEC 62C/269/CDV (1999) by 90 degrees counter-clockwise (in the negative direction) about the x-axis yields the DICOM Patient Coordinate System, i.e., (XDICOM, YDICOM, ZDICOM) = (XIEC, -ZIEC, YIEC). Refer to the latest IEC documentation for the current definition of the IEC PATIENT Coordinate System.

Many of the dosimetry concepts referred to in this document can be found in ICRU Report 50, Prescribing, Recording, and Reporting Photon Beam Therapy, International Commission on Radiation Units and Measurements, 1993.

#### C.8.8.1 RT Series Module

There exist significant differences in the manner in which RT objects as compared to diagnostic objects. An RT object can be one of several types, and a series of a given object type may be created over a temporal span of several weeks. The RT Series Module has been created to satisfy the requirements of the standard DICOM Query/Retrieve model while including only those attributes relevant to the identification and selection of radiotherapy objects.

Table C.8-37. RT Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data. Enumerated Values: RTIMAGE RT Image RTDOSE RT Dose RTSTRUCT RT Structure Set RTPLAN RT Plan RTRECORD RT Treatment Record See Section C.8.8.1.1.
Series Instance UID | (0020,000E) | 1 | Unique identifier of the series.
Series Number | (0020,0011) | 2 | A number that identifies this series.
Series Date | (0008,0021) | 3 | Date the Series started.
Series Time | (0008,0031) | 3 | Time the Series started.
Series Description | (0008,103E) | 3 | Description of the series.
Series Description Code Sequence | (0008,103F) | 3 | A coded description of the Series. Only a single Item is permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined.
Operators' Name | (0008,1070) | 2 | Name(s) of the operator(s) supporting the Series.
Referenced Performed Procedure Step Sequence | (0008,1111) | 3 | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. One or more items are permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Request Attributes Sequence | (0040,0275) | 3 | Sequence that contains attributes from the Imaging Service Request. One or more Items are permitted in this sequence.
>Include Table 10-9 “Request Attributes Macro Attributes” | No Baseline CID is defined.
Include Table 10-16 “Performed Procedure Step Summary Macro Attributes” | No Baseline CID is defined.

##### C.8.8.1.1 Modality

The Enumerated Value for Modality (0008,0060) shall determined by the IOD.

Enumerated Values if RT Image IOD:

RTIMAGE

Enumerated Values if RT Dose IOD:

RTDOSE

Enumerated Values if RT Structure Set IOD:

RTSTRUCT

Enumerated Values if RT Plan IOD or RT Ion Plan IOD:

RTPLAN

Enumerated Values if RT Beams Treatment Record IOD, RT Ion Beams Treatment Record IOD, RT Brachy Treatment Record IOD, or RT Treatment Summary Record IOD:

RTRECORD

### Note

DICOM specifies that a given series shall contain objects of only one Modality, and shall be created by a single device (described in the General Equipment Module). However, in general there may be many series defined for a given modality/device pair. Note that a radiotherapy series is generally created over an extended time interval (unlike in radiology, where all images in an image series are generally created together).

#### C.8.8.2 RT Image Module

Table C.8-38 contains attributes that describe RT-specific characteristics of a projection image. The image described by these attributes must be a radiotherapy image acquired or calculated using a conical imaging geometry.

Table C.8-38. RT Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.8.8.2.6.1 for specialization.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.8.2.6.2 for specialization.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See Section C.8.8.2.6.3 for specialization.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See Section C.8.8.2.6.4 for specialization.
High Bit | (0028,0102) | 1 | Most significant bit for each pixel sample. Each sample shall have the same high bit. See Section C.8.8.2.6.5 for specialization.
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Each sample shall have the same pixel representation. See Section C.8.8.2.6.6 for specialization.
Pixel Intensity Relationship | (0028,1040) | 3 | The relationship between the Pixel sample values and the X-Ray beam intensity. Enumerated Values: LIN Linearly proportional to X-Ray beam intensity LOG Logarithmically proportional to X-Ray beam intensity See Section C.8.11.3.1.2 for further explanation.
Pixel Intensity Relationship Sign | (0028,1041) | 1C | The sign of the relationship between the Pixel sample values stored in Pixel Data (7FE0,0010) and the X-Ray beam intensity. Required if Pixel Intensity Relationship (0028,1040) is present. Enumerated Values: 1 Lower pixel values correspond to less X-Ray beam intensity -1 Higher pixel values correspond to less X-Ray beam intensity See Section C.8.11.3.1.2 for further explanation.
RT Image Label | (3002,0002) | 1 | User-defined label for RT Image.
RT Image Name | (3002,0003) | 3 | User-defined name for RT Image.
RT Image Description | (3002,0004) | 3 | User-defined description of RT Image.
Image Type | (0008,0008) | 1 | Image identification characteristics (see Section C.7.6.1.1.2). Defined Terms for Value 3: DRR digitally reconstructed radiograph PORTAL digital portal image or portal film image SIMULATOR conventional simulator image RADIOGRAPH radiographic image BLANK image pixels set to background value FLUENCE fluence map
Conversion Type | (0008,0064) | 2 | Describes the kind of image conversion. Defined Terms: DV Digitized Video DI Digital Interface DF Digitized Film WSD Workstation
Reported Values Origin | (3002,000A) | 2C | Describes the origin of the parameter values reported in the image. Required if Value 3 of Image Type (0008,0008) is SIMULATOR or PORTAL. Enumerated Values: OPERATOR manually entered by operator PLAN planned parameter values ACTUAL electronically recorded
RT Image Plane | (3002,000C) | 1 | Describes whether or not image plane is normal to beam axis. Enumerated Values: NORMAL image plane normal to beam axis NON_NORMAL image plane non-normal to beam axis
X-Ray Image Receptor Translation | (3002,000D) | 3 | Position in (x,y,z) coordinates of origin of IEC X-RAY IMAGE RECEPTOR System in the IEC GANTRY coordinate system (mm). See Note 2.
X-Ray Image Receptor Angle | (3002,000E) | 2 | X-Ray Image Receptor Angle i.e., orientation of IEC X-RAY IMAGE RECEPTOR coordinate system with respect to IEC GANTRY coordinate system (degrees). See Section C.8.8.2.2.
RT Image Orientation | (3002,0010) | 2C | The direction cosines of the first row and the first column with respect to the IEC X-RAY IMAGE RECEPTOR coordinate system. Required if RT Image Plane (3002,000C) is NON_NORMAL. May be present otherwise.
Image Plane Pixel Spacing | (3002,0011) | 2 | Physical distance (in mm) between the center of each image pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing. See Section C.8.8.2.3 and Section 10.7.1.3 for further explanation.
RT Image Position | (3002,0012) | 2 | The x and y coordinates (in mm) of the upper left hand corner of the image, in the IEC X-RAY IMAGE RECEPTOR coordinate system. This is the center of the first pixel transmitted. See Section C.8.8.2.7.
Radiation Machine Name | (3002,0020) | 2 | User-defined name identifying radiation machine used in acquiring or computing image (i.e., name of conventional simulator, electron accelerator, X-Ray device, or machine modeled when calculating DRR).
Primary Dosimeter Unit | (300A,00B3) | 2 | Measurement unit of machine dosimeter. Enumerated Values: MU Monitor Unit MINUTE minute
Radiation Machine SAD | (3002,0022) | 2 | Radiation source to Gantry rotation axis distance of radiation machine used in acquiring or computing image (mm).
Radiation Machine SSD | (3002,0024) | 3 | Source to patient surface distance (in mm) of radiation machine used in acquiring or computing image.
RT Image SID | (3002,0026) | 2 | Distance from radiation machine source to image plane (in mm) along radiation beam axis. See Section C.8.8.2.3.
Source to Reference Object Distance | (3002,0028) | 3 | Source to reference object distance (in mm), as used for magnification calculation of RADIOGRAPH and SIMULATOR images.
Referenced RT Plan Sequence | (300C,0002) | 3 | Sequence of one Class/Instance pair describing RT Plan associated with image. Only a single item is permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Referenced Beam Number | (300C,0006) | 3 | Uniquely identifies the corresponding N-segment treatment beam specified by Beam Number (300A,00C0) within Beam Sequence in RT Beams Module within the RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
Referenced Fraction Group Number | (300C,0022) | 3 | Identifier of Fraction Group within RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
Fraction Number | (3002,0029) | 3 | Fraction Number of fraction during which image was acquired, within Fraction Group referenced by Referenced Fraction Group Number (300C,0022) within RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
Start Cumulative Meterset Weight | (300C,0008) | 3 | Cumulative Meterset Weight within Beam referenced by Referenced Beam Number (300C,0006) at which image acquisition starts.
End Cumulative Meterset Weight | (300C,0009) | 3 | Cumulative Meterset Weight within Beam referenced by Referenced Beam Number (300C,0006) at which image acquisition ends.
Exposure Sequence | (3002,0030) | 3 | Sequence of Exposure parameter sets, corresponding to exposures used in generating the image. One or more items are permitted in this sequence. See Section C.8.8.2.4.
>Referenced Frame Number | (0008,1160) | 1C | Identifies corresponding image frame in multi-frame image. Required if there is more than one item in Exposure Sequence (3002,0030), and image is a multi-frame image.
>KVP | (0018,0060) | 2C | Peak kilo voltage output (kV) of X-Ray generator used to acquire image. Required if Value 3 of Image Type (0008,0008) is PORTAL, SIMULATOR or RADIOGRAPH.
>Primary Fluence Mode Sequence | (3002,0050) | 3 | Sequence defining whether the primary fluence of the treatment beam uses a non-standard fluence-shaping. Only a single Item is permitted in this sequence.
>>Fluence Mode | (3002,0051) | 1 | Describes whether the fluence shaping is the standard mode for the beam or an alternate. Enumerated Values: STANDARD Uses standard fluence-shaping NON_STANDARD Uses a non-standard fluence-shaping mode
>>Fluence Mode ID | (3002,0052) | 1C | Identifier for the specific fluence-shaping mode. Required if Fluence Mode (3002,0051) has value NON_STANDARD.
>X-Ray Tube Current | (0018,1151) | 2C | Imaging device X-Ray Tube Current (mA). Required if Value 3 of Image Type (0008,0008) is SIMULATOR or RADIOGRAPH. May be present otherwise.
>X-Ray Tube Current in mA | (0018,9330) | 3 | X-Ray Tube Current in mA. An average in the case of fluoroscopy (continuous radiation mode).
>Exposure Time | (0018,1150) | 2C | Time of X-Ray exposure (msec). Required if Value 3 of Image Type (0008,0008) is SIMULATOR or RADIOGRAPH. May be present otherwise.
>Exposure Time in ms | (0018,9328) | 3 | Duration of X-Ray exposure in msec.
>Meterset Exposure | (3002,0032) | 2C | Treatment machine Meterset duration over which image has been acquired, specified in Monitor units (MU) or minutes as defined by Primary Dosimeter Unit (300A,00B3). Required if Value 3 of Image Type (0008,0008) is PORTAL.
>Diaphragm Position | (3002,0034) | 3 | Positions of diaphragm jaw pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis in the IEC order X1, X2, Y1, Y2.
>Beam Limiting Device Sequence | (300A,00B6) | 3 | Sequence of beam limiting device (collimator) jaw or leaf (element) positions for given exposure. One or more items are permitted in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Source to Beam Limiting Device Distance | (300A,00BA) | 3 | Radiation source to beam limiting device (collimator) distance (mm).
>>Number of Leaf/Jaw Pairs | (300A,00BC) | 1 | Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).
>>Leaf Position Boundaries | (300A,00BE) | 2C | Boundaries (in mm) of beam limiting device (collimator) leaves (elements) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), i.e., X-axis for MLCY, Y-axis for MLCX. Contains N+1 values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), starting from Leaf (Element) Pair 1. Required if RT Beam Limiting Device Type (300A,00B8) is MLCX or MLCY. May be present otherwise.
>>Leaf/Jaw Positions | (300A,011C) | 1 | Positions of beam limiting device (collimator) leaf or jaw (element) pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g., X-axis for MLCX, Y-axis for MLCY). Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), in IEC leaf (element) subscript order 101, 102, … 1N, 201, 202, … 2N.
>Gantry Angle | (300A,011E) | 3 | Treatment machine gantry angle, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees).
>Gantry Pitch Angle | (300A,014A) | 3 | Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). See Section C.8.8.25.6.5.
>Beam Limiting Device Angle | (300A,0120) | 3 | Treatment machine beam limiting device (collimator) angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees).
>Patient Support Angle | (300A,0122) | 3 | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees).
>Table Top Pitch Angle | (300A,0140) | 3 | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). See Section C.8.8.25.6.2.
>Table Top Roll Angle | (300A,0144) | 3 | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system (degrees). See Section C.8.8.25.6.2.
>Table Top Vertical Position | (300A,0128) | 3 | Table Top Vertical position in IEC TABLE TOP coordinate system (mm).
>Table Top Longitudinal Position | (300A,0129) | 3 | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm).
>Table Top Lateral Position | (300A,012A) | 3 | Table Top Lateral position in IEC TABLE TOP coordinate system (mm).
>Applicator Sequence | (300A,0107) | 3 | Sequence of Applicators associated with Beam. Only a single item is permitted in this sequence.
>>Applicator ID | (300A,0108) | 1 | User or machine supplied identifier for Applicator.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Applicator Type | (300A,0109) | 1 | Type of Applicator. Defined Terms: ELECTRON_SQUARE square electron applicator ELECTRON_RECT rectangular electron applicator ELECTRON_CIRC circular electron applicator ELECTRON_SHORT short electron applicator ELECTRON_OPEN open (dummy) electron applicator PHOTON_SQUARE square photon applicator PHOTON_RECT rectangular photon applicator PHOTON_CIRC circular photon applicator INTRAOPERATIVE intraoperative (custom) applicator STEREOTACTIC stereotactic applicator (deprecated)
>>Applicator Geometry Sequence | (300A,0431) | 3 | Describes the applicator aperture geometry. Only a single Item is permitted in this sequence.
>>>Applicator Aperture Shape | (300A,0432) | 1 | Aperture shape of the applicator. Defined Terms: SYM_SQUARE A square-shaped aperture symmetrical to the central axis. SYM_RECTANGLE A rectangular-shaped aperture symmetrical to the central axis. SYM_CIRCULAR A circular-shaped aperture symmetrical to the central axis.
>>>Applicator Opening | (300A,0433) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system. In case of square-shaped applicator contains the length of the sides of the square. In case of circular-shaped applicators, contains the diameter of the circular aperture. Required if Applicator Aperture Shape (300A,0432) is SYM_SQUARE or SYM_CIRCULAR.
>>>Applicator Opening X | (300A,0434) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in X-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>>>Applicator Opening Y | (300A,0435) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in Y-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>> Source to Applicator Mounting Position Distance | (300A,0436) | 3 | Radiation source to applicator mounting position distance (in mm) for current applicator.
>>Applicator Description | (300A,010A) | 3 | User-defined description for Applicator.
>General Accessory Sequence | (300A,0420) | 3 | Sequence of General Accessories associated with the beam producing this image. One or more items are permitted in this sequence.
>>General Accessory Number | (300A,0424) | 1 | Identification Number of the General Accessory. The value shall be unique within the sequence.
>>General Accessory ID | (300A,0421) | 1 | User or machine supplied identifier for General Accessory.
>>General Accessory Description | (300A,0422) | 3 | User supplied description of General Accessory.
>>General Accessory Type | (300A,0423) | 3 | Specifies the type of accessory. Defined Terms: GRATICULE Accessory tray with a radio-opaque grid IMAGE_DETECTOR Image acquisition device positioned in the beam line RETICLE Accessory tray with radio-transparent markers or grid
>>Accessory Code | (300A,00F9) | 3 | Machine-readable identifier for this accessory
>>Source to General Accessory Distance | (300A,0425) | 3 | Radiation source to general accessory distance (in mm) for current accessory.
>Number of Blocks | (300A,00F0) | 1 | Number of shielding blocks associated with Beam.
>Block Sequence | (300A,00F4) | 2C | Sequence of blocks associated with Beam. Required if Number of Blocks (300A,00F0) is non-zero. Zero or more items shall be included in this sequence.
>>Block Tray ID | (300A,00F5) | 3 | User-supplied identifier for block tray.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Source to Block Tray Distance | (300A,00F6) | 2 | Radiation Source to attachment edge of block tray assembly (mm).
>>Block Type | (300A,00F8) | 1 | Type of block. Enumerated Values: SHIELDING blocking material is inside contour APERTURE blocking material is outside contour
>>Block Divergence | (300A,00FA) | 2 | Indicates presence or otherwise of geometrical divergence Enumerated Values: PRESENT block edges are shaped for beam divergence ABSENT block edges are not shaped for beam divergence
>>Block Mounting Position | (300A,00FB) | 3 | Indicates on which side of the Block Tray the block is mounted. Enumerated Values: PATIENT_SIDE the block is mounted on the side of the Block Tray that is towards the patient. SOURCE_SIDE the block is mounted on the side of the Block Tray that is towards the radiation source.
>>Block Number | (300A,00FC) | 1 | Identification Number of the Block. The value of Block Number (300A,00FC) shall be unique within the Beam in which it is created.
>>Block Name | (300A,00FE) | 3 | User-defined name for block.
>>Material ID | (300A,00E1) | 2 | User-supplied identifier for material used to manufacture Block.
>>Block Thickness | (300A,0100) | 3 | Physical thickness of block (in mm) parallel to radiation beam axis.
>>Block Number of Points | (300A,0104) | 2 | Number of (x,y) pairs defining the block edge.
>>Block Data | (300A,0106) | 2 | A data stream of (x,y) pairs that comprise the block edge. The number of pairs shall be equal to Block Number of Points (300A,0104), and the vertices shall be interpreted as a closed polygon. Coordinates are projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).
Fluence Map Sequence | (3002,0040) | 1C | A Sequence of data describing the fluence map attributes for a radiotherapy beam. Only a single item shall be included in this sequence. Required if the third value of Image Type (0008,0008) is FLUENCE.
>Fluence Data Source | (3002,0041) | 1 | Source of fluence data. Enumerated Values: CALCULATED Calculated by a workstation MEASURED Measured by exposure to a film or detector.
>Fluence Data Scale | (3002,0042) | 3 | The Meterset corresponding with a fluence map cell value of 1.0 expressed in units specified by Primary Dosimeter Units (300A,00B3). This is the Meterset value used for treatment, not the Meterset used to expose the film as defined by Meterset Exposure (3002,0032).
Gantry Angle | (300A,011E) | 3 | Treatment machine gantry angle, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees).
Gantry Pitch Angle | (300A,014A) | 3 | Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). See Section C.8.8.25.6.5.
Beam Limiting Device Angle | (300A,0120) | 3 | Treatment machine beam limiting device (collimator) angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees).
Patient Support Angle | (300A,0122) | 3 | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees).
Table Top Eccentric Axis Distance | (300A,0124) | 3 | Distance (positive) from the IEC PATIENT SUPPORT vertical axis to the IEC TABLE TOP ECCENTRIC vertical axis (mm).
Table Top Eccentric Angle | (300A,0125) | 3 | Table Top (non-isocentric) angle, i.e., orientation of IEC TABLE TOP ECCENTRIC coordinate system with respect to IEC PATIENT SUPPORT system (degrees).
Table Top Pitch Angle | (300A,0140) | 3 | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). See Section C.8.8.25.6.2.
Table Top Roll Angle | (300A,0144) | 3 | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system (degrees). See Section C.8.8.25.6.2.
Table Top Vertical Position | (300A,0128) | 3 | Table Top Vertical position in IEC TABLE TOP coordinate system (mm).
Table Top Longitudinal Position | (300A,0129) | 3 | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm).
Table Top Lateral Position | (300A,012A) | 3 | Table Top Lateral position in IEC TABLE TOP coordinate system (mm).
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based IEC coordinate system to the patient-based coordinate system.
Patient Position | (0018,5100) | 1C | Patient position descriptor relative to the patient support device. Required if Isocenter Position (300A,012C) is present. May be present otherwise. See Section C.8.8.12.1.2 for Defined Terms and further explanation. ### Note The orientation of the patient relative to the patient support device is denoted in the same manner as in the RT Patient Setup module. It defines the relation of the patient-based DICOM coordinate system identified by the frame of reference module of the RT Image to the IEC coordinate system and together with Isocenter Position (300A,012C) allows the RT Image to be placed into the patient frame of reference. It also allows a system using an RT Image to verify that the patient is setup in a similar position relative to the patient support device.

### Note

1. The numeric beam data parameters recorded with the RT Image correspond to the parameters as they were known at the time the image was created or taken. The parameters may or may not correspond to an actual RT Plan instance that is created for a patient. If the Reported Values Origin (3002,000A) has an Enumerated Value of OPERATOR or ACTUAL and there is an RT Plan reference present, the numeric beam data parameters may or may not be the same in the two objects.

2. The Z coordinate of the X-Ray Image Receptor Translation (3002,000D) will be equal to the Radiation Machine SAD (3002,0022) minus the RT Image SID (3002,0026). If the image receptor is further from the beam source than the machine isocenter, the Z coordinate will be negative (see IEC 61217).

##### C.8.8.2.1 Multi-frame Image Data

In either multiple exposure multi-frame images or cine images, only the attributes inside Exposure Sequence (3002,0030) shall differ between frames. For example, attributes such as beam limiting device (collimator) leaf (element) positions and block information may change, whereas attributes such as gantry and beam limiting device (collimator) angle shall not change.

##### C.8.8.2.2 X-Ray Image Receptor Angle

The X-Ray Image Receptor Angle (3002,000E) specifies the rotation of the image receptor device in the IEC X-RAY IMAGE RECEPTOR PLANE. A positive angle corresponds to a counter-clockwise rotation of the X-Ray Image Receptor as viewed from the radiation source in the IEC GANTRY coordinate system. The normal (non-rotated) value for this parameter is zero degrees.

##### C.8.8.2.3 Image Plane Pixel Spacing and RT Image SID

The Image Plane Pixel Spacing (3002,0011) attribute shall always be defined on the image plane, i.e., at the radiation machine source to image plane distance specified by RT Image SID (3002,0026). For images where the source-image distance is undefined or unknown (e.g., DRR images), RT Image SID (3002,0026) shall equal Radiation Machine SAD (3002,0022) and Image Plane Pixel Spacing (3002,0011) shall be defined on this common plane.

##### C.8.8.2.4 Exposure Sequence

Exposure Sequence (3002,0030) allows specification of imaging parameters and aperture definitions for single exposure images (single item sequence), integrated images (multiple item sequence) or multiple exposures (multiple item sequence). An integrated image is a single-frame image (no Cine or Multi-frame Module present) with multiple items in the Exposure Sequence. A Referenced Frame Number (0008,1160) is not provided. A multiple exposure image can be expressed as a multi-frame image containing either a single frame, or more than one frame. Referenced Frame Number (0008,1160) shall be specified for each Exposure Sequence item for multiple exposure images expressed using more than one frame.

Many of the attributes referring to beam parameters can be present both inside Exposure Sequence (3002,0030) and outside the sequence. When a specific attribute is present inside the sequence, that attribute shall supersede the attribute found outside Exposure Sequence (3002,0030). For any item in the sequence, if the attribute is not present, the value of the attribute (if specified) outside the sequence shall be used.

##### C.8.8.2.5 Single Frame and Multi-frame Images

If the Multi-frame Module is present and the Cine Module is not present then the Frame Increment Pointer (0028,0009) shall have the Enumerated Value of 00200013 (Instance Number). If the Multi-frame Module and Cine Module are both present then the Frame Increment Pointer (0028,0009) shall have an Enumerated Value of either 00181063 (Frame Time) or 00181065 (Frame Time Vector).

##### C.8.8.2.6 Image Pixel Module Attributes

###### C.8.8.2.6.1 Samples Per Pixel

Enumerated Values:

1

###### C.8.8.2.6.2 Photometric Interpretation

Enumerated Values:

MONOCHROME2

###### C.8.8.2.6.3 Bits Allocated

Enumerated Values:

8

16

###### C.8.8.2.6.4 Bits Stored

Enumerated Values when Bits Allocated (0028,0100) is 8:

8

Enumerated Values when Bits Allocated (0028,0100) is 16:

12

13

14

15

16

###### C.8.8.2.6.5 High Bit

For RT Images, High Bit (0028,0102) shall be one less than the value sent in Bits Stored (0028,0101).

###### C.8.8.2.6.6 Pixel Representation

Enumerated Values when Bits Allocated (0028,0100) is 8:

0000H

  unsigned integer

##### C.8.8.2.7 RT Image Plane, Position and Orientation

When RT Image Plane (3002,000C) is NORMAL and RT Image Orientation (3002,0010) is not provided, the orientation is defined as follows: The image viewing direction goes from the radiation source to the image (i.e., in the sense of a beam's eye view, or along the negative Zr direction of the IEC X-RAY IMAGE RECEPTOR coordinate system). The direction of rows goes along the positive Xr direction and the direction of the columns goes along the negative Yr direction of the IEC X-RAY IMAGE RECEPTOR coordinate system. Other interpretations shall be documented in an implementation's conformance statement.

#### C.8.8.3 RT Dose Module

The RT Dose module is used to convey 2D or 3D radiation dose data generated from treatment planning systems or similar devices. The attributes defined within the module support dose for a single radiation beam (potentially comprised of multiple segments, as delivered in a dynamic treatment) or a group of beams comprising either a fraction group (see Section C.8.8.13) or a complete treatment plan (potentially the sum of multiple fraction groups).

The RT Dose module provides the mechanism to transmit a 3D array of dose data as a set of 2D dose planes that may or may not be related to CT or MR image planes. This mechanism works via the DICOM Multi-frame module that is required if multi-frame pixel data are sent.

Table C.8-39. RT Dose Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Samples per Pixel | (0028,0002) | 1C | Number of samples (planes) in this image. See Section C.8.8.3.4.1 for specialization. Required if Pixel Data (7FE0,0010) is present.
Photometric Interpretation | (0028,0004) | 1C | Specifies the intended interpretation of the pixel data. See Section C.8.8.3.4.2 for specialization. Required if Pixel Data (7FE0,0010) is present.
Bits Allocated | (0028,0100) | 1C | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See Section C.8.8.3.4.3 for specialization. Required Pixel Data (7FE0,0010) is present.
Bits Stored | (0028,0101) | 1C | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See Section C.8.8.3.4.4 for specialization. Required if Pixel Data (7FE0,0010) is present.
High Bit | (0028,0102) | 1C | Most significant bit for each pixel sample. Each sample shall have the same high bit. See Section C.8.8.3.4.5 for specialization. Required if Pixel Data (7FE0,0010) is present.
Pixel Representation | (0028,0103) | 1C | Data representation of the pixel samples. Each sample shall have the same pixel representation. See Section C.8.8.3.4.6 for specialization. Required Pixel Data (7FE0,0010) is present.
Dose Units | (3004,0002) | 1 | Units used to describe dose. Enumerated Values: GY Gray RELATIVE dose relative to implicit reference value
Dose Type | (3004,0004) | 1 | Type of dose. Defined Terms: PHYSICAL physical dose EFFECTIVE physical dose after correction for biological effect using user-defined modeling technique ERROR difference between desired and planned dose
Spatial Transform of Dose | (3004,0005) | 3 | The use of transformation in the calculation of the combined dose. Defined Terms: NONE No transformation. Calculated on the original image set RIGID Only Rigid transform used (see definition in Section C.20.2.1.2) NON_RIGID Any other transform used
Referenced Spatial Registration Sequence | (0070,0404) | 2C | A reference to a Spatial Registration SOP Instance or a Deformable Spatial Registration SOP Instance, which defines the transformation used to transform the dose. Required, if Spatial Transform of Dose (3004,0005) is provided and has a value of RIGID or NON_RIGID. Zero or more items shall be included in this sequence. See Section C.8.8.3.5
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Instance Number | (0020,0013) | 3 | A number that identifies this object instance.
Dose Comment | (3004,0006) | 3 | User-defined comments for dose data.
Normalization Point | (3004,0008) | 3 | Coordinates (x, y, z) of normalization point in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). See Section C.8.8.3.1.
Dose Summation Type | (3004,000A) | 1 | Type of dose summation. Defined Terms: PLAN dose calculated for entire delivery of all fraction groups of RT Plan MULTI_PLAN dose calculated for entire delivery of 2 or more RT Plans FRACTION dose calculated for entire delivery of a single Fraction Group within RT Plan BEAM dose calculated for entire delivery of one or more Beams within RT Plan BRACHY dose calculated for entire delivery of one or more Brachy Application Setups within RT Plan FRACTION_SESSION dose calculated for a single session ("fraction") of a single Fraction Group within RT Plan BEAM_SESSION dose calculated for a single session ("fraction") of one or more Beams within RT Plan BRACHY_SESSION dose calculated for a single session ("fraction") of one or more Brachy Application Setups within RT Plan CONTROL_POINT dose calculated for one or more Control Points within a Beam for a single fraction RECORD dose calculated for RT Beams Treatment Record
Referenced RT Plan Sequence | (300C,0002) | 1C | Sequence describing RT Plan associated with dose. Required if Dose Summation Type (3004,000A) is PLAN, MULTI_PLAN, FRACTION, BEAM, BRACHY, FRACTION_SESSION, BEAM_SESSION, BRACHY_SESSION or CONTROL_POINT. Only a single item shall be included in this sequence, unless Dose Summation Type (3004,000A) is MULTI_PLAN, in which case two or more items shall be included in this sequence. See Note 1.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Referenced Fraction Group Sequence | (300C,0020) | 1C | Sequence of one Fraction Group containing beams or brachy application setups contributing to dose. Required if Dose Summation Type (3004,000A) is FRACTION, BEAM, BRACHY, FRACTION_SESSION, BEAM_SESSION, BRACHY_SESSION or CONTROL_POINT. Only a single item shall be included in this sequence. See Note 1.
>>Referenced Fraction Group Number | (300C,0022) | 1 | Uniquely identifies Fraction Group specified by Fraction Group Number (300A,0071) in Fraction Group Sequence of RT Fraction Scheme Module within RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
>>Referenced Beam Sequence | (300C,0004) | 1C | Sequence of Beams in current Fraction Group contributing to dose. Required if Dose Summation Type (3004,000A) is BEAM, BEAM_SESSION or CONTROL_POINT. One or more items shall be included in this sequence.
>>>Referenced Beam Number | (300C,0006) | 1 | Uniquely identifies Beam specified by Beam Number (300A,00C0) in Beam Sequence of RT Beams Module within RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
>>>Referenced Control Point Sequence | (300C,00F2) | 1C | Sequence defining the Control Points in current Beam contributing to dose. Required if Dose Summation Type (3004,000A) is CONTROL_POINT. Only a single item shall be included in this sequence.
>>>>Referenced Start Control Point Index | (300C,00F4) | 1 | Identifies Control Point specified by Control Point Index (300A,0112) within Beam referenced by Referenced Beam Number (300C,0006). This is the first of the two Control Points from which the Dose contribution to the Control Point can be calculated.
>>>>Referenced Stop Control Point Index | (300C,00F6) | 1 | Identifies Control Point specified by Control Point Index (300A,0112) within Beam referenced by Referenced Beam Number (300C,0006). This is the second of the two Control Points from which the Dose contribution to the Control Point can be calculated. The Control Point Index (300A,0112) referenced by Referenced Stop Control Point Index (300C,00F6) shall be the Control Point Index (300A,0112) immediately following the Control Point Index (300A,0112) referenced by Referenced Start Control Point Index (300C,00F4) within the Referenced Beam Number (300C,0006).
>>Referenced Brachy Application Setup Sequence | (300C,000A) | 1C | Sequence of Brachy Application Setups in current Fraction Group contributing to dose. Required if Dose Summation Type (3004,000A) is BRACHY or BRACHY_SESSION. One or more items shall be included in this sequence.
>>>Referenced Brachy Application Setup Number | (300C,000C) | 1 | Uniquely identifies Brachy Application Setup specified by Brachy Application Setup Number (300A,0234) in Brachy Application Setup Sequence (300A,0230) of RT Brachy Application Setups Module within RT Plan referenced in Referenced RT Plan Sequence (300C,0002).
Referenced Treatment Record Sequence | (3008,0030) | 1C | Sequence describing RT Beams Treatment Record associated with dose. One or more Items shall be included in this sequence. Required if Dose Summation Type (3004,000A) is RECORD.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Referenced Beam Sequence | (300C,0004) | 1C | Sequence of Beams contributing to dose. One or more items shall be included in this sequence. Required, if the dose does not apply to the complete RT Beams Treatment Record referenced in the Referenced Treatment Record Sequence (3008,0030).
>>Referenced Beam Number | (300C,0006) | 1 | Uniquely identifies Beam specified by Beam Number (300A,00C0) in Beam Sequence of RT Beams Module within RT Beams Treatment Record referenced in the Referenced Treatment Record Sequence (3008,0030).
Grid Frame Offset Vector | (3004,000C) | 1C | An array that contains the dose image plane offsets (in mm) of the dose image frames in a multi-frame dose. Required if multi-frame pixel data are present and Frame Increment Pointer (0028,0009) points to Grid Frame Offset Vector (3004,000C). See Section C.8.8.3.2.
Dose Grid Scaling | (3004,000E) | 1C | Scaling factor that when multiplied by the dose grid data found in Pixel Data (7FE0,0010) attribute of the Image Pixel Module, yields grid doses in the dose units as specified by Dose Units (3004,0002). Required if Pixel Data (7FE0,0010) is present.
Tissue Heterogeneity Correction | (3004,0014) | 3 | Specifies a list of patient heterogeneity characteristics used for calculating dose. This Attribute shall be multi-valued if beams used to compute the dose have differing correction techniques. Enumerated Values: IMAGE image data ROI_OVERRIDE one or more ROI densities override image or water values where they exist WATER entire volume treated as water equivalent
Derivation Code Sequence | (0008,9215) | 3 | A coded description of how this dose was derived from other RT Dose and/or RT Plan objects. One or more Items are permitted in this Sequence. More than one Item indicates that successive derivation steps have been applied.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7220 “RT Dose Derivation”.
Referenced Instance Sequence | (0008,114A) | 3 | The set of SOP Instances used to derive this RT Dose SOP instance. One or more Items are permitted in this Sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Code describing the purpose of the reference to the Instance(s). Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7221 “RT Dose Purpose of Reference”.

### Note

In order to prevent misrepresentation of the dose summation:

1. If the Dose Summation Type (3004,000A) is PLAN, then only a single instance of RT Plan is referenced and the dose will be for the entire plan (i.e., it is not viable to combine only certain fraction groups of different plans).

2. If the Dose Summation Type (3004,000A) is MULTI_PLAN, then 2 or more instances of RT Plan may be referenced. As above, each reference will be for the entire plan.

3. If the Dose Summation Type (3004,000A) is FRACTION or FRACTION_SESSION, then only a single instance of RT PLAN and a single Fraction Group are referenced (i.e., component beams or brachy application setups are not referenced).

##### C.8.8.3.1 Normalization Point

Normalization Point (3004,0008) aids in the interpretation and subsequent use of the transmitted data. If used, it shall be a point receiving dose contributions from all referenced components of the dose summation.

##### C.8.8.3.2 Grid Frame Offset Vector

Grid Frame Offset Vector (3004,000C) shall be provided if a dose distribution is sent as a multi-frame image. Values of the Grid Frame Offset Vector (3004,000C) shall vary monotonically and are to be interpreted as follows:

1. If Grid Frame Offset Vector (3004,000C) is present and its first element is zero, this attribute contains an array of n elements indicating the plane location of the data in the right-handed image coordinate system, relative to the position of the first dose plane transmitted, i.e., the point at which Image Position (Patient) (0020,0032) is defined, with positive offsets in the direction of the cross product of the row and column directions.

2. If Grid Frame Offset Vector (3004,000C) is present, its first element is equal to the third element of Image Position (Patient) (0020,0032), and Image Orientation (Patient) (0020,0037) has the value (1,0,0,0,1,0), then Grid Frame Offset Vector contains an array of n elements indicating the plane location (patient z coordinate) of the data in the patient coordinate system.

In future implementations, use of option a) is strongly recommended.

This attribute is conditional since the RT Dose module may be included even if pixel doses are not being transmitted, or the image may be a single-frame image. If the Multi-frame Module is present, Frame Increment Pointer (0028,0009) shall have the Enumerated Value of 3004000C (Grid Frame Offset Vector).

### Note

Option (a) can represent a rectangular-parallelepiped dose grid with any orientation with respect to the patient, while option (b) can only represent a rectangular-parallelepiped dose grid whose planes are in the transverse patient dimension and whose x- and y-axes are parallel to the patient x- and y-axes.

Example: Figure C.8.8.3-1 shows an example of plane positions for a dose grid with transverse planes.

Figure C.8.8.3-1. Dose Grid Frame Example

For this example, Table C.8-39b gives the values of elements in the Grid Frame Offset Vector (3004,000C) for both relative (option (a)) and absolute (option (b)) interpretations, under the following conditions:

1. The value of Image Orientation (Patient) (0020,0037) is (1,0,0,0,1,0). I.e., the dose grid is transverse with x- and y-axes parallel to the patient x- and y-axes;

2. The value of Image Position (Patient) (0020,0032), i.e., the position of the first element of the dose grid, is (4, 5, 6); and

3. The spacing between adjacent dose grid planes is 2mm (uniform).

Table C.8-39b. Values of Dose Grid Frame Offset Vector Under Relative (A) and Absolute (B) Interpretations

Grid Frame Offset Vector Element | Option (a) Relative Coordinates | Option (b) Absolute Coordinates
--- | --- | ---
Z1 | 0 | 6
Z2 | 2 | 8
Z3 | 4 | 10
ZN | 2(N-1) | 6 + 2(N-1)

##### C.8.8.3.3 Dose Units

Dose Units are specified in both the RT Dose and RT Dose ROI modules. The attribute Dose Type present in the RT Dose module shall apply to all doses present in the RT Dose IOD.

##### C.8.8.3.4 Image Pixel Module Attributes

###### C.8.8.3.4.1 Samples Per Pixel

Enumerated Values:

1

###### C.8.8.3.4.2 Photometric Interpretation

Enumerated Values:

MONOCHROME2

###### C.8.8.3.4.3 Bits Allocated

Enumerated Values:

16

32

###### C.8.8.3.4.4 Bits Stored

For RT Doses, Bits Stored (0028,0101) shall be equal to Bits Allocated (0028,0100).

###### C.8.8.3.4.5 High Bit

For RT Doses, High Bit (0028,0102) shall be one less than the value sent in Bits Stored (0028,0101).

###### C.8.8.3.4.6 Pixel Representation

Enumerated Values when Dose Type (3004,0004) = ERROR:

0001H

  two's complement integer,

Enumerated Values when Dose Type (3004,0004) not ERROR:

0000H

  unsigned integer, otherwise.

##### C.8.8.3.5 Referenced Spatial Registration Sequence

This sequence lists the registrations used to create the dose. It is important to note, that this sequence does not make any statement about how the dose was calculated or about the scope of objects contributing to a summed dose.

#### C.8.8.4 RT DVH Module

The RT DVH module provides for the inclusion of differential or cumulative dose volume histogram data. The data contained within this module may supplement dose data in the RT Dose and/or RT Dose ROI modules, or it may be present in the absence of other dose data.

Table C.8-40. RT DVH Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Referenced Structure Set Sequence | (300C,0060) | 1 | Sequence of one class/instance pair describing Structure Set containing structures that are used to calculate Dose-Volume Histograms (DVHs). Only a single item shall be included in this sequence. See Section C.8.8.4.1.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
DVH Normalization Point | (3004,0040) | 3 | Coordinates (x, y, z) of common DVH normalization point in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).
DVH Normalization Dose Value | (3004,0042) | 3 | Dose Value at DVH Normalization Point (3004,0040) used as reference for individual DVHs when Dose Units (3004,0002) is RELATIVE.
DVH Sequence | (3004,0050) | 1 | Sequence of DVHs. One or more items shall be included in this sequence.
>DVH Referenced ROI Sequence | (3004,0060) | 1 | Sequence of referenced ROIs used to calculate DVH. One or more items shall be included in this sequence.
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies ROI used to calculate DVH specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set referenced by referenced RT Plan in Referenced RT Plan Sequence (300C,0002) in RT Dose Module.
>>DVH ROI Contribution Type | (3004,0062) | 1 | Specifies whether volume within ROI is included or excluded in DVH. See Section C.8.8.4.2. Enumerated Values: INCLUDED EXCLUDED
>DVH Type | (3004,0001) | 1 | Type of DVH. Enumerated Values: DIFFERENTIAL differential dose-volume histogram CUMULATIVE cumulative dose-volume histogram NATURAL natural dose volume histogram
>Dose Units | (3004,0002) | 1 | Dose axis units. Enumerated Values: GY Gray RELATIVE dose relative to reference value specified in DVH Normalization Dose Value (3004,0042)
>Dose Type | (3004,0004) | 1 | Type of dose. Defined Terms: PHYSICAL physical dose EFFECTIVE physical dose after correction for biological effect using user-defined modeling technique ERROR difference between desired and planned dose
>DVH Dose Scaling | (3004,0052) | 1 | Scaling factor that when multiplied by the dose bin widths found in DVH Data (3004,0058), yields dose bin widths in the dose units as specified by Dose Units (3004,0002).
>DVH Volume Units | (3004,0054) | 1 | Volume axis units. Defined Terms: CM3 cubic centimeters PERCENT percent PER_U volume per u with u(dose)=dose-3/2. See Section C.8.8.4.3.
>DVH Number of Bins | (3004,0056) | 1 | Number of bins n used to store DVH Data (3004,0058).
>DVH Data | (3004,0058) | 1 | A data stream describing the dose bin widths Dnand associated volumes Vnin DVH Volume Units (3004,0054) in the order D1V1, D2V2, … DnVn. ### Note DVH Data arrays may not be properly encoded if Explicit VR transfer syntax is used and the VL of this attribute exceeds 65534 bytes.
>DVH Minimum Dose | (3004,0070) | 3 | Minimum calculated dose to ROI(s) described by DVH Referenced ROI Sequence (3004,0060).
>DVH Maximum Dose | (3004,0072) | 3 | Maximum calculated dose to ROI(s) described by DVH Referenced ROI Sequence (3004,0060).
>DVH Mean Dose | (3004,0074) | 3 | Mean calculated dose to ROI(s) described by DVH Referenced ROI Sequence (3004,0060).

##### C.8.8.4.1 Referenced Structure Set Sequence

The Referenced Structure Set Sequence (300C,0060) is required for direct cross-reference of the dose bin data with the corresponding ROI(s) from which they were derived. ROIs referenced by the DVH Referenced ROI Sequence (3004,0050) shall only contain contours with a Contour Geometric Type (3006,0042) of POINT or CLOSED_PLANAR.

##### C.8.8.4.2 DVH ROI Contribution Type

The volume used to calculate the DVH shall be the geometric union of ROIs where DVH ROI Contribution Type (3004,0062) is INCLUDED, minus the geometric union of ROIs where DVH ROI Contribution Type (3004,0062) is EXCLUDED.

##### C.8.8.4.3 DVH Volume Units

The unit PER_U is defined in: Anderson, LL: "A "natural" volume-dose histogram for brachytherapy", Medical Physics 13(6) pp 898-903, 1986.

#### C.8.8.5 Structure Set Module

A structure set defines a set of areas of significance. Each area can be associated with a Frame of Reference and zero or more images. Information that can be transferred with each region of interest (ROI) includes geometrical and display parameters, and generation technique.

Table C.8-41. Structure Set Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Structure Set Label | (3006,0002) | 1 | User-defined label for Structure Set.
Structure Set Name | (3006,0004) | 3 | User-defined name for Structure Set.
Structure Set Description | (3006,0006) | 3 | User-defined description for Structure Set.
Instance Number | (0020,0013) | 3 | A number that identifies this object instance.
Structure Set Date | (3006,0008) | 2 | Date at which Structure Set was last modified.
Structure Set Time | (3006,0009) | 2 | Time at which Structure Set was last modified.
Referenced Frame of Reference Sequence | (3006,0010) | 3 | Sequence describing Frames of Reference in which the ROIs are defined. One or more items are permitted in this sequence. See Section C.8.8.5.1.
>Frame of Reference UID | (0020,0052) | 1 | Uniquely identifies Frame of Reference within Structure Set.
>RT Referenced Study Sequence | (3006,0012) | 3 | Sequence of Studies containing series to be referenced. One or more items are permitted in this sequence. See Section C.8.8.5.4.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>>RT Referenced Series Sequence | (3006,0014) | 1 | Sequence describing series of images within the referenced study that are used in defining the Structure Set. One or more items shall be included in this sequence.
>>>Series Instance UID | (0020,000E) | 1 | Unique identifier for the series containing the images.
>>>Contour Image Sequence | (3006,0016) | 1 | Sequence of items describing images in a given series used in defining the Structure Set (typically CT or MR images). One or more items shall be included in this sequence.
>>>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
Structure Set ROI Sequence | (3006,0020) | 1 | ROIs for current Structure Set. One or more items shall be included in this sequence.
>ROI Number | (3006,0022) | 1 | Identification number of the ROI. The value of ROI Number (3006,0022) shall be unique within the Structure Set in which it is created.
>Referenced Frame of Reference UID | (3006,0024) | 1 | Uniquely identifies Frame of Reference in which ROI is defined, specified by Frame of Reference UID (0020,0052) in Referenced Frame of Reference Sequence (3006,0010).
>ROI Name | (3006,0026) | 2 | User-defined name for ROI.
>ROI Description | (3006,0028) | 3 | User-defined description for ROI.
>ROI Volume | (3006,002C) | 3 | Volume of ROI (cubic centimeters).
>ROI Generation Algorithm | (3006,0036) | 2 | Type of algorithm used to generate ROI. Defined Terms: AUTOMATIC calculated ROI SEMIAUTOMATIC ROI calculated with user assistance MANUAL user-entered ROI
>ROI Generation Description | (3006,0038) | 3 | User-defined description of technique used to generate ROI.
>Derivation Code Sequence | (0008,9215) | 3 | A coded description of how this ROI was derived. One or more items are permitted in this Sequence. See Section C.8.8.5.3 for further explanation.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Enumerated Value (113085, DCM, "Spatial resampling").
Predecessor Structure Set Sequence | (3006,0018) | 3 | The Structure Set that has been used to derive the current Structure Set. Only a single item is permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

##### C.8.8.5.1 Frames of Reference

The Referenced Frame of Reference Sequence (3006,0010) describes a set of frames of reference in which some or all of the ROIs are expressed. Since the Referenced Frame of Reference UID (3006,0024) is required for each ROI, each frame of reference used to express the coordinates of an ROI shall be listed in the Referenced Frame of Reference Sequence (3006,0010) once and only once.

### Note

As an example, a set of ROIs defined using a single image series would list the image series in a single Referenced Frame of Reference Sequence (3006,0010) item, providing the UID for this referenced frame of reference (obtained from the source images), and listing all pertinent images in the Contour Image Sequence (3006,0016).

##### C.8.8.5.2 Frame of Reference Relationship Sequence and Transformation Matrix

Retired. See PS3.3-2011.

The concept of definition of registered frame of references using the Frame of Reference Relationship Sequence (3006,00C0) formerly present in the standard is retired. The use of Registration IODs is advised since the introduction of Spatial Registration IOD, which is a much stronger and more general concept, and independent from the specifics of RT Structure Sets. Additionally it is of importance that registrations are decoupled from image and segmentation objects.

##### C.8.8.5.3 ROI Derivation Sequence

If an ROI is created by re-sampling an existing ROI that is either (a) present in a different Frame of Reference (FoR) and has been resampled to align with the image series referenced by the current structure set, or (b) present in the same FoR, but its contours are referenced to a different image series, it is useful to be able to identify that the ROI is resampled. The Derivation Code Sequence (0008,9215) shall be used with code (113085, DCM, "Spatial resampling") to indicate the resampled ROI.

##### C.8.8.5.4 SOP Class UID in RT Referenced Study Sequence

Since RT Referenced Study Sequence (3006,0012) is Type 3, the attribute may be omitted.

If RT Referenced Study Sequence (3006,0012) is present with an Item, the SOP Class UID of the Detached Study Management SOP Class (Retired) may be used in Referenced SOP Class UID (0008,1150).

#### C.8.8.6 ROI Contour Module

In general, a ROI can be defined by either a sequence of overlays or a sequence of contours. This module, if present, is used to define the ROI as a set of contours. Each ROI contains a sequence of one or more contours, where a contour is either a single point (for a point ROI) or more than one point (representing an open or closed polygon).

Table C.8-42. ROI Contour Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
ROI Contour Sequence | (3006,0039) | 1 | Sequence of Contour Sequences defining ROIs. One or more items shall be included in this sequence.
>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies the referenced ROI described in the Structure Set ROI Sequence (3006,0020).
>ROI Display Color | (3006,002A) | 3 | RGB triplet color representation for ROI, specified using the range 0-255.
>Contour Sequence | (3006,0040) | 3 | Sequence of Contours defining ROI. One or more items are permitted in this sequence.
>>Contour Number | (3006,0048) | 3 | Identification number of the contour. The value of Contour Number (3006,0048) shall be unique within the Contour Sequence (3006,0040) in which it is defined. No semantics or ordering shall be inferred from this attribute.
>>Attached Contours | (3006,0049) | 3 | List of Contour Number (3006,0048) defining lower-numbered contour(s) to which the current contour is connected.
>>Contour Image Sequence | (3006,0016) | 3 | Sequence of images containing the contour. One or more items are permitted in this sequence.
>>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>>Contour Geometric Type | (3006,0042) | 1 | Geometric type of contour. See Section C.8.8.6.1. Enumerated Values: POINT single point OPEN_PLANAR open contour containing coplanar points OPEN_NONPLANAR open contour containing non-coplanar points CLOSED_PLANAR closed contour (polygon) containing coplanar points
>>Contour Slab Thickness | (3006,0044) | 3 | Thickness of slab (in mm) represented by contour, where Contour Data (3006,0050) defines a plane in the center of the slab, offset by the Contour Offset Vector (3006,0045) if it is present. See Section C.8.8.6.2.
>>Contour Offset Vector | (3006,0045) | 3 | Vector (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 that is normal to plane of Contour Data (3006,0050), describing direction and magnitude of the offset (in mm) of each point of the central plane of a contour slab from the corresponding original point of Contour Data (3006,0050). See Section C.8.8.6.2.
>>Number of Contour Points | (3006,0046) | 1 | Number of points (triplets) in Contour Data (3006,0050).
>>Contour Data | (3006,0050) | 1 | Sequence of (x,y,z) triplets defining a contour in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). See Section C.8.8.6.1 and Section C.8.8.6.3. ### Note Contour Data may not be properly encoded if Explicit VR transfer syntax is used and the VL of this attribute exceeds 65534 bytes.

##### C.8.8.6.1 Contour Geometric Type

A contour can be one of the following geometric types:

- A Contour Geometric Type (3006,0042) of POINT indicates that the contour is a single point, defining a specific location of significance.

- A Contour Geometric Type (3006,0042) of OPEN_PLANAR indicates that the last vertex shall not be connected to the first point, and that all points in Contour Data (3006,0050) shall be coplanar.

- A Contour Geometric Type (3006,0042) of OPEN_NONPLANAR indicates that the last vertex shall not be connected to the first point, and that the points in Contour Data (3006,0050) may be non-coplanar. Contours having a Geometric Type (3006,0042) of OPEN_NONPLANAR can be used to represent objects best described by a single, possibly non-coplanar curve, such as a brachytherapy applicator.

- A Contour Geometric Type (3006,0042) of CLOSED_PLANAR indicates that the last point shall be connected to the first point, where the first point is not repeated in Contour Data (3006,0050). All points in Contour Data (3006,0050) shall be coplanar.

##### C.8.8.6.2 Contour Slab Thickness

A set of Contour slabs may define a multi-slab Volume of Interest. Contour Slab Thickness (3006,0044) shall specify the thickness of a slab, the central plane of which shall be defined by the set of points offset from Contour Data (3006,0050) by the value of Contour Offset Vector (3006,0045). One contour slab may contain one to many sets of Contour Data (3006,0050) that may define regions of one complex Volume of Interest. If no valid value of Contour Slab Thickness (3006,0044) is sent, then the offset value shall be (0,0,0) and the original Contour Data (3006,0050) shall define the central plane of the Contour slab.

##### C.8.8.6.3 Representing Inner and Outer Contours on an Image

When a single ROI describes an excluded inner volume, this can be encoded with a single contour, using a "keyhole" technique. In this method, an arbitrarily narrow channel is used to connect the outer contour to the inner contour, so that it is drawn as a single contour. An example of such a structure is shown in Figure C.8.8.6-1

Points in space lying along the path defined by the contour are considered to be inside the ROI.

Figure C.8.8.6-1. Example of ROI with excluded inner volume

#### C.8.8.7 RT Dose ROI Module

RT Dose ROI provides ancillary dose-related information to the ROI data defined within the Structure Set and ROI Contour modules, which may be included in the RT Dose IOD composite object. These modules in combination provide for the definition of dose data in the form of isodose curves or named or unnamed dose points. Isodose curves in radiation oncology are simply contours identifying a set of points with the same dose value.

Table C.8-43. RT Dose ROI Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
RT Dose ROI Sequence | (3004,0010) | 1 | Sequence specifying dose levels for isodose curves or dose points described in the ROI module. One or more items shall be included in this sequence. See Section C.8.8.7.1.
>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies the referenced ROI within the current RT Dose. See Note 1 and Section C.8.8.7.2.
>Dose Units | (3004,0002) | 1 | Units used for ROI Dose. Enumerated Values: GY Gray RELATIVE dose relative to implicit reference value
>Dose Value | (3004,0012) | 1 | Dose value for ROI, in units defined by Dose Units (3004,0002). See Section C.8.8.7.3.

### Note

1. The Structure Set ROI Sequence (3006,0020) defining the dose point and surfaces is defined in the Structure Set module. ROI Number (3006,0022) is unique within the Structure Set ROI Sequence, and is referenced from the RT Dose ROI module using Referenced ROI Number (3006,0084).

2. The RT Dose ROI module defines the attributes that describe references to ROIs contained within the associated Structure Set and RT ROI Contour modules. Note that the RT Dose module table specifies that either all or none of the modules Structures Set, ROI Contour, and RT Dose ROI must be present in the RT Dose IOD.

##### C.8.8.7.1 Contour Geometric Type of Referenced ROI

ROIs referenced in the RT Dose ROI Module shall have a Contour Geometric Type (3006,0042) of POINT, OPEN_PLANAR or CLOSED_PLANAR.

##### C.8.8.7.2 Referenced ROI Number

There shall be a one-to-one correspondence between Referenced ROI Number (3006,0084) and the sequence of ROIs defined in the Structure Set and ROI Contour modules. The RT Dose ROI module shall only contain references to structures that are dose-related (i.e., dose points and isodose curves).

##### C.8.8.7.3 Dose Value

Dose Value (3004,0012) shall be the dose value corresponding to the referenced isodose curve, named dose point, or unnamed dose point.

#### C.8.8.8 RT ROI Observations Module

The RT ROI Observations module specifies the identification and interpretation of an ROI specified in the Structure Set and ROI Contour modules.

Table C.8-44. RT ROI Observations Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
RT ROI Observations Sequence | (3006,0080) | 1 | Sequence of observations related to ROIs defined in the ROI Module. One or more items shall be included in this sequence.
>Observation Number | (3006,0082) | 1 | Identification number of the Observation. The value of Observation Number (3006,0082) shall be unique within the RT ROI Observations Sequence (3006,0080).
>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies the referenced ROI described in the Structure Set ROI Sequence (3006,0020).
>ROI Observation Label | (3006,0085) | 3 | User-defined label for ROI Observation.
>ROI Observation Description | (3006,0088) | 3 | User-defined description for ROI Observation.
>RT Related ROI Sequence | (3006,0030) | 3 | Sequence of significantly related ROIs, e.g., CTVs contained within a PTV. One or more items are permitted in this sequence.
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies the related ROI described in the Structure Set ROI Sequence (3006,0020).
>>RT ROI Relationship | (3006,0033) | 3 | Relationship of referenced ROI with respect to referencing ROI. Defined Terms: SAME ROIs represent the same entity ENCLOSED referenced ROI completely encloses referencing ROI ENCLOSING referencing ROI completely encloses referenced ROI
>Segmented Property Category Code Sequence | (0062,0003) | 3 | Sequence defining the general category of this ROI. Only a single Item is permitted in this sequence. See Note 1.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined.
>RT ROI Identification Code Sequence | (3006,0086) | 3 | Sequence containing Code used to identify ROI. Only a single Item is permitted in this sequence. See Note 2.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined.
>Additional RT ROI Identification Code Sequence | (3006,00B9) | 3 | Sequence containing Code used to identify ROI for a particular purpose. One or more items may be present in this sequence. See Section C.8.8.8.2.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined.
>>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the identification code is assigned.
>>>Include Table 8.8-1 “Code Sequence Macro Attributes” | No Baseline CID is defined. There shall be a private code scheme defined why there is an ROI identification code.
>Related RT ROI Observations Sequence | (3006,00A0) | 3 | Sequence of related ROI Observations. One or more items are permitted in this sequence.
>>Observation Number | (3006,0082) | 1 | Uniquely identifies a related ROI Observation.
>RT ROI Interpreted Type | (3006,00A4) | 2 | Type of ROI. See Section C.8.8.8.1. Defined Terms: EXTERNAL external patient contour PTV Planning Target Volume (as defined in ICRU50) CTV Clinical Target Volume (as defined in ICRU50) GTV Gross Tumor Volume (as defined in ICRU50) TREATED_VOLUME Treated Volume (as defined in ICRU50) IRRAD_VOLUME Irradiated Volume (as defined in ICRU50) BOLUS patient bolus to be used for external beam therapy AVOIDANCE region in which dose is to be minimized ORGAN patient organ MARKER patient marker or marker on a localizer REGISTRATION registration ROI ISOCENTER treatment isocenter to be used for external beam therapy CONTRAST_AGENT volume into which a contrast agent has been injected CAVITY patient anatomical cavity BRACHY_CHANNEL brachytherapy channel BRACHY_ACCESSORY brachytherapy accessory device BRACHY_SRC_APP brachytherapy source applicator BRACHY_CHNL_SHLD brachytherapy channel shield SUPPORT external patient support device FIXATION external patient fixation or immobilization device DOSE_REGION ROI to be used as a dose reference CONTROL ROI to be used in control of dose optimization and calculation
>ROI Interpreter | (3006,00A6) | 2 | Name of person performing the interpretation.
>Material ID | (300A,00E1) | 3 | User-supplied identifier for ROI material.
>ROI Physical Properties Sequence | (3006,00B0) | 3 | Sequence describing physical properties associated with current ROI interpretation. One or more items are permitted in this sequence.
>>ROI Physical Property | (3006,00B2) | 1 | Physical property specified by ROI Physical Property Value (3006,00B4). Defined Terms: REL_MASS_DENSITY mass density relative to water REL_ELEC_DENSITY electron density relative to water EFFECTIVE_Z effective atomic number EFF_Z_PER_A ratio of effective atomic number to mass (AMU-1) REL_STOP_RATIO linear stopping power ratio relative to water ELEM_FRACTION elemental composition of the material
>>ROI Elemental Composition Sequence | (3006,00B6) | 1C | The elemental composition of the ROI and the atomic mass fraction of the elements in the ROI. Required if ROI Physical Property (3006,00B2) equals ELEM_FRACTION. One or more items shall be included in this sequence.
>>>ROI Elemental Composition Atomic Number | (3006,00B7) | 1 | The atomic number of the element for which the ROI Elemental Composition Sequence (3006,00B6) is sent.
>>>ROI Elemental Composition Atomic Mass Fraction | (3006,00B8) | 1 | The fractional weight of the element for which the ROI Elemental Composition Sequence (3006,00B6) is sent. The sum of all ROI Elemental Composition Atomic Mass Fractions (3006,00B8) sent in the ROI Elemental Composition Sequence (3006,00B6) shall equal 1.0 within acceptable limits of floating point precision.
>>ROI Physical Property Value | (3006,00B4) | 1 | User-assigned value for physical property. ### Note The value has no meaning when ROI Physical Property (3006,00B2) has the value ELEM_FRACTION. Therefore this attribute may contain any value and receivers may ignore that value.

### Note

1. This attribute allows preserving information by copying the content of Segmented Property Category Code Sequence (0062,0003) in case a Segmentation object is re-encoded as an RT Structure Set or vice-versa.

2. In case of re-encoding a Segmentation object as an RT Structure Set or vice-versa it is suggested, that the Segmented Property Type Code Sequence (0062,000F) is mapped to RT ROI Identification Code Sequence (3006,0086).

##### C.8.8.8.1 RT ROI Interpreted Type

RT ROI Interpreted Type (3006,00A4) shall describe the class of ROI (e.g., CTV, PTV). Individual instances of each class of structure (e.g., CTV1, CTV2) can be distinguished using ROI Observation Label (3006,0085).

##### C.8.8.8.2 Additional RT ROI Identification Code Sequence

The Additional RT ROI Identification Code Sequence (3006,00B9) is to provide the facility to annotate the ROI with additional codes. Such additional codes are positioned to support cross-institutional, cross-application classification for clinical workflow, automated treatment planning, DVH analysis etc. The code provided in the Purpose of Reference Code Sequence (0040,A170) allows to identify the scope of use of the Additional RT ROI Identification Code (e.g., data registries and clinical trials, cross-institutional, cross-application classification for clinical workflow, automated treatment planning).

#### C.8.8.9 RT General Plan Module

Table C.8-45. RT General Plan Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
RT Plan Label | (300A,0002) | 1 | User-defined label for treatment plan.
RT Plan Name | (300A,0003) | 3 | User-defined name for treatment plan.
RT Plan Description | (300A,0004) | 3 | User-defined description of treatment plan.
Instance Number | (0020,0013) | 3 | A number that identifies this object instance.
RT Plan Date | (300A,0006) | 2 | Date treatment plan was last modified.
RT Plan Time | (300A,0007) | 2 | Time treatment plan was last modified.
Treatment Protocols | (300A,0009) | 3 | Planned treatment protocols.
Plan Intent | (300A,000A) | 3 | Intent of this plan. Defined Terms: CURATIVE Curative therapy on patient PALLIATIVE Palliative therapy on patient PROPHYLACTIC Preventative therapy on patient VERIFICATION Verification of patient plan using phantom MACHINE_QA Quality assurance of the delivery machine (independently of a specific patient) RESEARCH Research project SERVICE Machine repair or maintenance operation
Treatment Sites | (300A,000B) | 3 | Planned treatment sites.
RT Plan Geometry | (300A,000C) | 1 | Describes whether RT Plan is based on patient or treatment device geometry. See Section C.8.8.9.1. Defined Terms: PATIENT RT Structure Set exists TREATMENT_DEVICE RT Structure Set does not exist
Referenced Structure Set Sequence | (300C,0060) | 1C | The RT Structure Set on which the RT Plan is based. Only a single item shall be included in this sequence. Required if RT Plan Geometry (300A,000C) is PATIENT.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Referenced Dose Sequence | (300C,0080) | 3 | Related instances of RT Dose (for grids and named/unnamed point doses). One or more items are permitted in this sequence. See Note 1.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Referenced RT Plan Sequence | (300C,0002) | 3 | Related instances of RT Plan. One or more items are permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>RT Plan Relationship | (300A,0055) | 1 | Relationship of referenced plan with respect to current plan. Defined Terms: PRIOR plan delivered prior to current treatment ALTERNATIVE alternative plan prepared for current treatment PREDECESSOR plan used in derivation of current plan VERIFIED_PLAN plan that is verified using the current plan. This value shall only be used if Plan Intent (300A,000A) is present and has a value of VERIFICATION CONCURRENT plan that forms part of a set of two or more RT Plan instances representing a single conceptual 'plan', applied in parallel in one treatment phase

### Note

An RT Dose IOD referenced within the Referenced Dose Sequence (300C,0080) can be used for storing grid-based (pixel) data, individual dose points (with optional dose point names), isodose curves, and DVHs.

##### C.8.8.9.1 Referenced Structure Set Sequence

An RT Plan Geometry (300A,000C) of PATIENT shall signify that an RT Structure Set has been defined upon which the plan geometry is based, and this RT Structure Set shall be specified in the Referenced Structure Set Sequence (300C,0060). An RT Plan Geometry (300A,000C) of TREATMENT_DEVICE shall indicate that no patient geometry is available, and that the RT Plan is being defined with respect to the IEC FIXED Coordinate System.

#### C.8.8.10 RT Prescription Module

Table C.8-46. RT Prescription Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Prescription Description | (300A,000E) | 3 | User-defined description of treatment prescription.
Dose Reference Sequence | (300A,0010) | 3 | Sequence of Dose References. One or more items are permitted in this sequence.
>Dose Reference Number | (300A,0012) | 1 | Identification number of the Dose Reference. The value of Dose Reference Number (300A,0012) shall be unique within the RT Plan in which it is created.
>Dose Reference UID | (300A,0013) | 3 | A unique identifier for a Dose Reference that can be used to link the same entity across multiple RT Plan objects.
>Dose Reference Structure Type | (300A,0014) | 1 | Structure type of Dose Reference. Defined Terms: POINT dose reference point specified as ROI VOLUME dose reference volume specified as ROI COORDINATES point specified by Dose Reference Point Coordinates (300A,0018) SITE dose reference clinical site
>Dose Reference Description | (300A,0016) | 3 | User-defined description of Dose Reference.
>Referenced ROI Number | (3006,0084) | 1C | Uniquely identifies ROI representing the dose reference specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module. Required if Dose Reference Structure Type (300A,0014) is POINT or VOLUME.
>Dose Reference Point Coordinates | (300A,0018) | 1C | Coordinates (x,y,z) of Reference Point in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). Required if Dose Reference Structure Type (300A,0014) is COORDINATES.
>Nominal Prior Dose | (300A,001A) | 3 | Dose (in Gy) from prior treatment to this Dose Reference (e.g., from a previous course of treatment).
>Dose Reference Type | (300A,0020) | 1 | Type of Dose Reference. Defined Terms: TARGET treatment target (corresponding to GTV, PTV, or CTV in ICRU50) ORGAN_AT_RISK Organ at Risk (as defined in ICRU50)
>Constraint Weight | (300A,0021) | 3 | Relative importance of satisfying constraint, where high values represent more important constraints.
>Delivery Warning Dose | (300A,0022) | 3 | The dose (in Gy) that when reached or exceeded should cause some action to be taken.
>Delivery Maximum Dose | (300A,0023) | 3 | The maximum dose (in Gy) that can be delivered to the dose reference.
>Target Minimum Dose | (300A,0025) | 3 | Minimum permitted dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) is TARGET.
>Target Prescription Dose | (300A,0026) | 3 | Prescribed dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) is TARGET.
>Target Maximum Dose | (300A,0027) | 3 | Maximum permitted dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) is TARGET.
>Target Underdose Volume Fraction | (300A,0028) | 3 | Maximum permitted fraction (in percent) of Target to receive less than the Target Prescription Dose if Dose Reference Type (300A,0020) is TARGET and Dose Reference Structure Type (300A,0014) is VOLUME. See Section C.8.8.10.1.
>Organ at Risk Full-volume Dose | (300A,002A) | 3 | Maximum dose (in Gy) to entire Dose Reference if Dose Reference Type (300A,0020) is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) is VOLUME.
>Organ at Risk Limit Dose | (300A,002B) | 3 | Maximum permitted dose (in Gy) to any part of Dose Reference if Dose Reference Type (300A,0020) is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) is VOLUME.
>Organ at Risk Maximum Dose | (300A,002C) | 3 | Maximum dose (in Gy) to non-overdosed part of Dose Reference if Dose Reference Type (300A,0020) is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) is VOLUME.
>Organ at Risk Overdose Volume Fraction | (300A,002D) | 3 | Maximum permitted fraction (in percent) of the Organ at Risk to receive more than the Organ at Risk Maximum Dose if Dose Reference Type (300A,0020) is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) is VOLUME.

##### C.8.8.10.1 Target Underdose Volume Fraction

If the Target Underdose Volume Fraction (300A,0028) is not present, it shall be interpreted as zero.

#### C.8.8.11 RT Tolerance Tables Module

Table C.8-47. RT Tolerance Tables Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Tolerance Table Sequence | (300A,0040) | 3 | Sequence of tolerance tables to be used for delivery of treatment plan. One or more items are permitted in this sequence. See Note 1.
>Tolerance Table Number | (300A,0042) | 1 | Identification number of the Tolerance Table. The value of Tolerance Table Number (300A,0042) shall be unique within the RT Plan in which it is created.
>Tolerance Table Label | (300A,0043) | 3 | User-defined label for Tolerance Table.
>Gantry Angle Tolerance | (300A,0044) | 3 | Maximum permitted difference (in degrees) between planned and delivered Gantry Angle.
>Gantry Pitch Angle Tolerance | (300A,014E) | 3 | Maximum permitted difference (in degrees) between planned and delivered Gantry Pitch Angle.
>Beam Limiting Device Angle Tolerance | (300A,0046) | 3 | Maximum permitted difference (in degrees) between planned and delivered Beam Limiting Device Angle.
>Beam Limiting Device Tolerance Sequence | (300A,0048) | 3 | Sequence of beam limiting device (collimator) tolerances. One or more items are permitted in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Beam Limiting Device Position Tolerance | (300A,004A) | 1 | Maximum permitted difference (in mm) between planned and delivered leaf (element) or jaw positions for current beam limiting device (collimator).
>Patient Support Angle Tolerance | (300A,004C) | 3 | Maximum permitted difference (in degrees) between planned and delivered Patient Support Angle.
>Table Top Eccentric Angle Tolerance | (300A,004E) | 3 | Maximum permitted difference (in degrees) between planned and delivered Table Top Eccentric Angle.
>Table Top Pitch Angle Tolerance | (300A,004F) | 3 | Maximum permitted difference (in degrees) between the planned and delivered Table Top Pitch Angle.
>Table Top Roll Angle Tolerance | (300A,0050) | 3 | Maximum permitted difference (in degrees) between the planned and delivered Table Top Roll Angle.
>Table Top Vertical Position Tolerance | (300A,0051) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Vertical Position.
>Table Top Longitudinal Position Tolerance | (300A,0052) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Longitudinal Position.
>Table Top Lateral Position Tolerance | (300A,0053) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Lateral Position.

### Note

Tolerance Tables may be used to compare planned with delivered machine parameters. If the absolute difference between the planned and delivered values exceeds the Tolerance Table value, treatment may be inhibited or the operator may be warned.

#### C.8.8.12 RT Patient Setup Module

The RT Patient Setup Module contains information describing the positioning of the patient with respect to the treatment machine, along with any fixation devices used. It also describes the shielding devices applied to the patient. The module contains a sequence of patient setup descriptions, each of which may be referenced by one of more beams or brachy application setups.

Table C.8-48. RT Patient Setup Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Patient Setup Sequence | (300A,0180) | 1 | Sequence of patient setup data for current plan. One or more items shall be included in this sequence.
>Patient Setup Number | (300A,0182) | 1 | Identification number of the Patient Setup. The value of Patient Setup Number (300A,0182) shall be unique within the RT Plan in which it is created.
>Patient Setup Label | (300A,0183) | 3 | The user-defined label for the patient setup.
>Patient Position | (0018,5100) | 1C | Patient position descriptor relative to the equipment. Required if Patient Additional Position (300A,0184) is not present. See Section C.8.8.12.1.2 for Defined Terms and further explanation.
>Patient Additional Position | (300A,0184) | 1C | User-defined additional description of patient position. Required if Patient Position (0018,5100) is not present.
>Referenced Setup Image Sequence | (300A,0401) | 3 | Sequence of setup verification images for this patient setup. One or more items are permitted in this sequence. See Section C.8.8.12.1.1
>>Setup Image Comment | (300A,0402) | 3 | Comment on the Setup Image.
>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Fixation Device Sequence | (300A,0190) | 3 | Sequence of Fixation Devices used in Patient Setup. One or more items are permitted in this sequence.
>>Fixation Device Type | (300A,0192) | 1 | Type of Fixation Device used during in Patient Setup. Defined Terms: BITEBLOCK HEADFRAME MASK MOLD CAST HEADREST BREAST_BOARD BODY_FRAME VACUUM_MOLD WHOLE_BODY_POD RECTAL_BALLOON
>>Fixation Device Label | (300A,0194) | 2 | User-defined label identifier for Fixation Device.
>>Fixation Device Description | (300A,0196) | 3 | User-defined description of Fixation Device.
>>Fixation Device Position | (300A,0198) | 3 | Position/Notch number of Fixation Device.
>>Fixation Device Pitch Angle | (300A,0199) | 3 | The Fixation Device Pitch Angle, i.e., orientation of PITCHED FIXATION DEVICE coordinate system with respect to IEC PATIENT SUPPORT coordinate system (degrees). Pitching is the rotation around IEC PATIENT SUPPORT X-axis.
>>Fixation Device Roll Angle | (300A,019A) | 3 | The Fixation Device Roll Angle, i.e., orientation of ROLLED FIXATION DEVICE coordinate system with respect to IEC PITCHED FIXATION DEVICE coordinate system (degrees). Rolling is the rotation around IEC PATIENT SUPPORT Y-axis.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>Shielding Device Sequence | (300A,01A0) | 3 | Sequence of Shielding Devices used in Patient Setup. One or more items are permitted in this sequence.
>>Shielding Device Type | (300A,01A2) | 1 | Type of Shielding Device used in Patient Setup. Defined Terms: GUM EYE GONAD
>>Shielding Device Label | (300A,01A4) | 2 | User-defined label for Shielding Device.
>>Shielding Device Description | (300A,01A6) | 3 | User-defined description of Shielding Device.
>>Shielding Device Position | (300A,01A8) | 3 | Position/Notch number of Shielding Device.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>Setup Technique | (300A,01B0) | 3 | Setup Technique used in Patient Setup. Defined Terms: ISOCENTRIC FIXED_SSD TBI BREAST_BRIDGE SKIN_APPOSITION
>Setup Technique Description | (300A,01B2) | 3 | User-defined description of Setup Technique.
>Setup Device Sequence | (300A,01B4) | 3 | Sequence of devices used for patient alignment in Patient Setup. One or more items are permitted in this sequence.
>>Setup Device Type | (300A,01B6) | 1 | Type of Setup Device used for Patient alignment. Defined Terms: LASER_POINTER DISTANCE_METER TABLE_HEIGHT MECHANICAL_PTR ARC
>>Setup Device Label | (300A,01B8) | 2 | User-defined label for Setup Device used for patient alignment.
>>Setup Device Description | (300A,01BA) | 3 | User-defined description for Setup Device used for patient alignment.
>>Setup Device Parameter | (300A,01BC) | 2 | Setup Parameter for Setup Device in appropriate IEC 61217 coordinate system. Units shall be mm for distances and degrees for angles.
>>Setup Reference Description | (300A,01D0) | 3 | User-defined description of Setup Reference used for patient alignment.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>Table Top Vertical Setup Displacement | (300A,01D2) | 3 | Vertical Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., vertical offset between patient positioning performed using setup and treatment position.
>Table Top Longitudinal Setup Displacement | (300A,01D4) | 3 | Longitudinal Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., longitudinal offset between patient positioning performed using setup and treatment position.
>Table Top Lateral Setup Displacement | (300A,01D6) | 3 | Lateral Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., lateral offset between patient positioning performed using setup and treatment position.
>Motion Synchronization Sequence | (300A,0410) | 3 | Sequence of Motion Synchronization. One or more items are permitted in this sequence.
>>Respiratory Motion Compensation Technique | (0018,9170) | 1 | Technique applied to reduce respiratory motion artifacts. Defined Terms: NONE BREATH_HOLD REALTIME image acquisition shorter than respiratory cycle GATING Prospective gating TRACKING prospective through-plane or in-plane motion tracking PHASE_ORDERING prospective phase ordering PHASE_RESCANNING prospective techniques, such as real-time averaging, diminishing variance and motion adaptive gating RETROSPECTIVE retrospective gating CORRECTION retrospective image correction UNKNOWN technique not known
>>Respiratory Signal Source | (0018,9171) | 1 | Signal source from which respiratory motion is derived. Defined Terms: NONE BELT NASAL_PROBE CO2_SENSOR NAVIGATOR MR navigator and organ edge detection MR_PHASE phase (of center k-space line) ECG baseline demodulation of the ECG SPIROMETER Signal derived from flow sensor EXTERNAL_MARKER Signal determined from external motion surrogate INTERNAL_MARKER Signal determined from internal motion surrogate IMAGE Signal derived from an image UNKNOWN Signal source not known
>>Respiratory Motion Compensation Technique Description | (0018,9185) | 3 | Description of respiratory motion compensation technique.
>>Respiratory Signal Source ID | (0018,9186) | 3 | Identifies the device providing the respiratory signal.

##### C.8.8.12.1 RT Patient Setup Module Attributes

###### C.8.8.12.1.1 Referenced Setup Image Sequence

Images with modality SC or VL serve as visible light photos for visual setup control. Images with modality RTIMAGE serve as reference images on plan level. RT Images present in this sequence shall not be referenced in the Referenced Reference Image Sequence (300C,0042) of the RT Beams module.

###### C.8.8.12.1.2 Patient Position

Defined Terms for Patient Position shall be those specified in Section C.7.3.1.1.2, plus the following:

Defined Terms:

SITTING

  In the sitting position, the patient's face is towards the front of the chair

#### C.8.8.13 RT Fraction Scheme Module

The RT Fraction Scheme module contains attributes that describe a single or multiple scheme of dose descriptions. Each sequence item contains dose specification information, fractionation patterns, and either beam or brachytherapy application setup specifications. The design of the RT Fraction Scheme module allows a beam or brachytherapy application setup to be used in multiple fraction schemes.

Table C.8-49. RT Fraction Scheme Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Fraction Group Sequence | (300A,0070) | 1 | Sequence of Fraction Groups in current Fraction Scheme. One or more items shall be included in this sequence.
>Fraction Group Number | (300A,0071) | 1 | Identification number of the Fraction Group. The value of Fraction Group Number (300A,0071) shall be unique within the RT Plan in which it is created.
>Fraction Group Description | (300A,0072) | 3 | The user defined description for the fraction group.
>Referenced Dose Sequence | (300C,0080) | 3 | Related instances of RT Dose (for grids, isodose curves and named/unnamed point doses). One or more items are permitted in this sequence. See Note 1.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Referenced Dose Reference Sequence | (300C,0050) | 3 | Sequence of Dose References for the current Fraction Group. One or more items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) within Dose Reference Sequence (300A,0010) in RT Prescription Module.
>>Constraint Weight | (300A,0021) | 3 | Relative importance of satisfying constraint, where high values represent more important constraints.
>>Delivery Warning Dose | (300A,0022) | 3 | The dose (in Gy) that when reached or exceeded should cause some action to be taken.
>>Delivery Maximum Dose | (300A,0023) | 3 | The maximum dose (in Gy) that can be delivered to the dose reference.
>>Target Minimum Dose | (300A,0025) | 3 | Minimum permitted dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is TARGET.
>>Target Prescription Dose | (300A,0026) | 3 | Prescribed dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is TARGET.
>>Target Maximum Dose | (300A,0027) | 3 | Maximum permitted dose (in Gy) to Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is TARGET.
>>Target Underdose Volume Fraction | (300A,0028) | 3 | Maximum permitted fraction (in percent) of Target to receive less than the Target Prescription Dose (300A,0027) if Dose Reference Type (300A,0020) of referenced Dose Reference is TARGET and Dose Reference Structure Type (300A,0014) of referenced Dose Reference is VOLUME.
>>Organ at Risk Full-volume Dose | (300A,002A) | 3 | Maximum dose (in Gy) to entire Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) of referenced Dose Reference is VOLUME.
>>Organ at Risk Limit Dose | (300A,002B) | 3 | Maximum permitted dose (in Gy) to any part of Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) of referenced Dose Reference is VOLUME.
>>Organ at Risk Maximum Dose | (300A,002C) | 3 | Maximum dose (in Gy) to non-overdosed part of Dose Reference if Dose Reference Type (300A,0020) of referenced Dose Reference is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) of referenced Dose Reference is VOLUME.
>>Organ at Risk Overdose Volume Fraction | (300A,002D) | 3 | Maximum permitted fraction (in percent) of Organ at Risk to receive more than the Organ at Risk Maximum Dose if Dose Reference Type (300A,0020) of referenced Dose Reference is ORGAN_AT_RISK and Dose Reference Structure Type (300A,0014) of referenced Dose Reference is VOLUME.
>Number of Fractions Planned | (300A,0078) | 2 | Total number of treatments (Fractions) prescribed for current Fraction Group.
>Number of Fraction Pattern Digits Per Day | (300A,0079) | 3 | Number of digits in Fraction Pattern (300A,007B) used to represent one day. See Note 2.
>Repeat Fraction Cycle Length | (300A,007A) | 3 | Number of weeks needed to describe treatment pattern. See Note 2.
>Fraction Pattern | (300A,007B) | 3 | String of 0's (no treatment) and 1's (treatment) describing treatment pattern. Length of string is 7 x Number of Fraction Pattern Digits Per Day x Repeat Fraction Cycle Length. Pattern shall start on a Monday. See Note 2.
>Beam Dose Meaning | (300A,008B) | 3 | Indicates the meaning of Beam Dose (300A,0084). Enumerated Values: BEAM_LEVEL Beam Dose value is individually calculated for this Beam FRACTION_LEVEL Dose is calculated on the Fraction level, and the value of Beam Dose (300A,0084) is assigned to the Beam to carry a nominally distributed dose only.
>Number of Beams | (300A,0080) | 1 | Number of Beams in current Fraction Group. If Number of Beams is greater then zero, Number of Brachy Application Setups (300A,00A0) shall equal zero.
>Referenced Beam Sequence | (300C,0004) | 1C | Sequence of treatment beams in current Fraction Group. One or more items shall be included in this sequence. Required if Number of Beams (300A,0080) is greater than zero.
>>Referenced Beam Number | (300C,0006) | 1 | Uniquely identifies Beam specified by Beam Number (300A,00C0) within Beam Sequence (300A,00B0) in RT Beams Module.
>>Beam Dose Specification Point | (300A,0082) | 3 | Coordinates (x,y,z) of point at which Beam Dose is specified in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). See Note 3.
>>Beam Dose | (300A,0084) | 3 | Dose (in Gy) at Beam Dose Specification Point (300A,0082) due to current Beam.
>>Beam Dose Verification Control Point Sequence | (300A,008C) | 3 | Sequence of Items containing Beam Dose Verification Control Points. Two or more items may be included in this sequence.
>>>Cumulative Meterset Weight | (300A,0134) | 1 | The cumulative Meterset weight value, at which the beam dose point geometrical parameters apply.
>>>Referenced Control Point Index | (300C,00F0) | 1C | Uniquely identifies the Control Point specified by Control Point Index (300A,0112) within Beam referenced by Referenced Beam Number (300C,0006). See Section C.8.8.13.1.1 Required, if the Referenced Cumulative Meterset corresponds to a Control Point in the Control Point Sequence (300A,0111).
>>>Average Beam Dose Point Depth | (300A,008D) | 2C | The average depth (in mm) in the patient along a ray from the source to the dose point specified by the Beam Dose Specification Point (300A,0082) from the current Beam Dose Verification Control Point to the next one. See Section C.8.8.13.1.2 Required for all but the last items in that sequence.
>>>Average Beam Dose Point Equivalent Depth | (300A,008E) | 2C | The average radiological depth in mm (water-equivalent depth, taking tissue heterogeneity into account) in the patient along a ray from the source to the dose point specified by the Beam Dose Specification Point (300A,0082) from the current Beam Dose Verification Control Point to the next one. See Section C.8.8.13.1.2 Required for all but the last items in that sequence.
>>>Average Beam Dose Point SSD | (300A,008F) | 2C | Average Source to patient surface distance in mm along a ray from the source to the dose point specified by the Beam Dose Specification Point (300A,0082) from the current Beam Dose Verification Control Point to the next one. See Section C.8.8.13.1.2 Required for all but the last items in that sequence.
>>Beam Meterset | (300A,0086) | 3 | Machine setting to be delivered for current Beam, specified in Monitor Units (MU) or minutes as defined by Primary Dosimeter Unit (300A,00B3) (in RT Beams Module) for referenced Beam. See Note 4.
>>Beam Delivery Duration Limit | (300A,00C5) | 3 | The expected maximum delivery time in sec. See Note 7.
>Number of Brachy Application Setups | (300A,00A0) | 1 | Number of Brachy Application Setups in current Fraction Group. If Number of Brachy Application Setups is greater then zero, Number of Beams (300A,0080) shall equal zero.
>Referenced Brachy Application Setup Sequence | (300C,000A) | 1C | Sequence of treatment Brachy Application Setups in current Fraction Group. Required if Number of Brachy Application Setups (300A,00A0) is greater than zero. One or more items shall be included in this sequence.
>>Referenced Brachy Application Setup Number | (300C,000C) | 1 | Uniquely identifies Brachy Application Setup specified by Brachy Application Setup Number (300A,0234) within Brachy Application Setup Sequence (300A,0230) in RT Brachy Application Setups Module.
>>Brachy Application Setup Dose Specification Point | (300A,00A2) | 3 | Coordinates (x,y,z) of point in the patient based coordinate system described in Section C.7.6.2.1.1 at which Brachy Application Setup Dose (300A,00A4) is specified (mm).
>>Brachy Application Setup Dose | (300A,00A4) | 3 | Dose (in Gy) at Brachy Application Setup Dose Specification Point (300A,00A2) due to current Brachy Application Setup.

### Note

1. An RT Dose IOD referenced within the Referenced Dose Sequence (300C,0080) can be used for storing grid-based (pixel) data, isodose curves, and/or individual dose points (with optional dose point names) for the current Fraction Group.

2. The fractionation pattern does not indicate the actual start of treatment, or the order or timing of fraction delivery. If treatment does not commence as outlined in the pattern, it is the application's responsibility to make any necessary adjustments.

   Examples of Fractionation Pattern Schemes:

   1. 1 fraction group, 1 fraction per day (Monday to Friday):

      - Number of Fraction Pattern Digits per Day = 1, Repeat Fraction Cycle Length = 1, Fraction Pattern = 1111100

   2. 2 fraction groups, 1 fraction per day, first fraction group Monday, Wednesday, and Friday, second fraction group Tuesday and Thursday:

      - Fraction Group 1: Number of Fraction Pattern Digits Per Day = 1, Repeat Fraction Cycle Length = 1, Fraction Pattern = 1010100

      - Fraction Group 2: Number of Fraction Pattern Digits Per Day = 1, Repeat Fraction Cycle Length = 1, Fraction Pattern = 0101000

   3. 2 fraction groups, 1 fraction per day, alternating fraction groups every day of treatment (Monday to Friday):

      - Fraction Group 1: Number of Fraction Pattern Digits Per Day = 1, Repeat Fraction Cycle Length = 2, Fraction Pattern = 10101000101000

      - Fraction Group 2: Number of Fraction Pattern Digits Per Day = 1, Repeat Fraction Cycle Length = 2, Fraction Pattern = 01010001010100

   4. 1 fraction group, 2 fractions per day (Monday to Friday):

      - Fraction Group 1: Number of Fraction Pattern Digits Per Day = 2, Repeat Fraction Cycle Length = 1, Fraction Pattern = 11111111110000

   5. 2 fraction groups, 2 fractions per day, alternating fraction groups every treatment (Monday to Friday):

      - Fraction Group 1: Number of Fraction Pattern Digits Per Day = 1, Repeat Fraction Cycle Length = 1, Fraction Pattern = 1111100

      - Fraction Group 2: Number of Fraction Pattern Digits Per Day = 2, Repeat Fraction Cycle Length = 1, Fraction Pattern = 11111111110000

3. The Beam Dose Specification Point (300A,0082) and Brachy Application Setup Dose Specification Point (300A,00A2) contain the coordinates of the single point used for dose normalization. This point is distinct from the Referenced Dose Reference Sequence (300C,0050) in the RT Beams module and the Brachy Referenced Dose Reference Sequence (300C,0055) in the RT Brachy Application Setups module, which are used for plan evaluation and dose tracking.

4. The Meterset at a given Control Point (see RT Beams Module) is equal to Beam Meterset (300A,0086) multiplied by the Cumulative Meterset Weight (300A,0134) for the Control Point, divided by the Final Cumulative Meterset Weight (300A,010E).

5. Attribute Referenced Patient Setup Number (300C,006A) was previously defined. Its use in this Module is now retired (see PS3.3-2004).

6. Attributes Beam Dose Point Depth, Beam Dose Point Equivalent Depth and Beam Dose Point SSD were previously included in this Module as optional Attributes but have been retired. See PS3.3-2011.

7. The Beam Delivery Duration Limit (300A,00C5) is the maximum time span allowed to deliver a single fraction of a beam to prevent significant over-treatments. Treatment is expected to be terminated upon reaching the Beam Delivery Duration Limit independent of the meterset. This limit represents the expected time span including some increase by a factor greater than 1 to accommodate normal variations in delivery.

##### C.8.8.13.1 Beam Dose Verification Parameters

###### C.8.8.13.1.1 Referenced Control Point

The number of items in the Beam Dose Verification Control Point Sequence (300A,008B) is not required to be the same as in the Control Point Sequence (300A,0111). A different sampling can be chosen for the Beam Dose Verification Control Point Sequence, but where the Cumulative Meterset Weight of a Control Point Sequence Item is the same it shall be referenced by the Referenced Control Point Index (300C,00F0).

###### C.8.8.13.1.2 Distance Parameters

The values given in Average Beam Dose Point Depth (300A,008D), Average Beam Dose Point Equivalent Depth (300A,008E) and Average Beam Dose Point SSD (300A,008F) shall always contain average values from the current Beam Dose Verification Control Point to the next. In case of e.g., an arc therapy, these values reflect the changing depth parameters. In case these distances do not change, e.g., for a static beam treatment, the average value equals the static value under the given geometric conditions.

#### C.8.8.14 RT Beams Module

The RT Beams Module contains information defining equipment parameters for delivery of external radiation beams.

Table C.8-50. RT Beams Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Beam Sequence | (300A,00B0) | 1 | Sequence of treatment beams for current RT Plan. One or more items shall be included in this sequence.
>Beam Number | (300A,00C0) | 1 | Identification number of the Beam. The value of Beam Number (300A,00C0) shall be unique within the RT Plan in which it is created. See Note 1.
>Beam Name | (300A,00C2) | 3 | User-defined name for Beam. See Note 1.
>Beam Description | (300A,00C3) | 3 | User-defined description for Beam. See Note 1.
>Beam Type | (300A,00C4) | 1 | Motion characteristic of Beam. See Note 5. Enumerated Values: STATIC All Control Point Sequence (300A,0111) attributes remain unchanged between consecutive pairs of control points with changing Cumulative Meterset Weight (300A,0134). DYNAMIC One or more Control Point Sequence (300A,0111) attributes change between one or more consecutive pairs of control points with changing Cumulative Meterset Weight (300A,0134).
>Radiation Type | (300A,00C6) | 2 | Particle type of Beam. Defined Terms: PHOTON ELECTRON NEUTRON PROTON
>Primary Fluence Mode Sequence | (3002,0050) | 3 | Sequence defining whether the primary fluence of the treatment beam uses a non-standard fluence-shaping. Only a single item is permitted in this sequence.
>>Fluence Mode | (3002,0051) | 1 | Describes whether the fluence shaping is the standard mode for the beam or an alternate. Enumerated Values: STANDARD Uses standard fluence-shaping NON_STANDARD Uses a non-standard fluence-shaping mode
>>Fluence Mode ID | (3002,0052) | 1C | Identifier for the specific fluence-shaping mode. Required if Fluence Mode (3002,0051) has value NON_STANDARD.
>High-Dose Technique Type | (300A,00C7) | 1C | Type of high-dose treatment technique. Defined Terms: TBI Total Body Irradiation HDR High Dose Rate Required if treatment technique requires a dose that would normally require overriding of treatment machine safety controls.
>Treatment Machine Name | (300A,00B2) | 2 | User-defined name identifying treatment machine to be used for beam delivery. See Note 2.
>Manufacturer | (0008,0070) | 3 | Manufacturer of the equipment to be used for beam delivery.
>Institution Name | (0008,0080) | 3 | Institution where the equipment is located that is to be used for beam delivery.
>Institution Address | (0008,0081) | 3 | Mailing address of the institution where the equipment is located that is to be used for beam delivery.
>Institutional Department Name | (0008,1040) | 3 | Department in the institution where the equipment is located that is to be used for beam delivery.
>Manufacturer's Model Name | (0008,1090) | 3 | Manufacturer's model name of the equipment that is to be used for beam delivery.
>Device Serial Number | (0018,1000) | 3 | Manufacturer's serial number of the equipment that is to be used for beam delivery.
>Primary Dosimeter Unit | (300A,00B3) | 3 | Measurement unit of machine dosimeter. See Section C.8.8.14.1. Enumerated Values: MU Monitor Unit MINUTE minute
>Referenced Tolerance Table Number | (300C,00A0) | 3 | Uniquely identifies Tolerance Table specified by Tolerance Table Number (300A,0042) within Tolerance Table Sequence in RT Tolerance Tables Module. These tolerances are to be used for verification of treatment machine settings.
>Source-Axis Distance | (300A,00B4) | 3 | Radiation source to Gantry rotation axis distance of the equipment that is to be used for beam delivery (mm).
>Beam Limiting Device Sequence | (300A,00B6) | 1 | Sequence of beam limiting device (collimator) jaw or leaf (element) sets. One or more items shall be included in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Source to Beam Limiting Device Distance | (300A,00BA) | 3 | Radiation source to beam limiting device (collimator) distance of the equipment that is to be used for beam delivery (mm).
>>Number of Leaf/Jaw Pairs | (300A,00BC) | 1 | Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).
>>Leaf Position Boundaries | (300A,00BE) | 2C | Boundaries of beam limiting device (collimator) leaves (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), i.e., X-axis for MLCY, Y-axis for MLCX. Contains N+1 values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), starting from Leaf (Element) Pair 1. Required if RT Beam Limiting Device Type (300A,00B8) is MLCX or MLCY. May be present otherwise. See Note 3.
>Referenced Patient Setup Number | (300C,006A) | 3 | Uniquely identifies Patient Setup to be used for current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence of RT Patient Setup Module.
>Referenced Reference Image Sequence | (300C,0042) | 3 | Reference images used for validation of current beam. One or more items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>>Reference Image Number | (300A,00C8) | 1 | Uniquely identifies Reference Image within Referenced Reference Image Sequence (300C,0042).
>>Start Cumulative Meterset Weight | (300C,0008) | 3 | Cumulative Meterset Weight within current Beam at which image acquisition starts.
>>End Cumulative Meterset Weight | (300C,0009) | 3 | Cumulative Meterset Weight within current Beam at which image acquisition ends.
>Planned Verification Image Sequence | (300A,00CA) | 3 | Sequence of planned verification images to be acquired during current beam. One or more items are permitted in this sequence. See Section C.8.8.14.2.
>>Start Cumulative Meterset Weight | (300C,0008) | 3 | Cumulative Meterset Weight within current Beam at which image acquisition will start.
>>Meterset Exposure | (3002,0032) | 3 | Meterset duration over which image is to be acquired, specified in Monitor units (MU) or minutes as defined by Primary Dosimeter Unit (300A,00B3).
>>End Cumulative Meterset Weight | (300C,0009) | 3 | Cumulative Meterset Weight within current Beam at which image acquisition will end.
>>RT Image Plane | (3002,000C) | 3 | Describes whether or not image plane is normal to beam axis. Enumerated Values: NORMAL image plane normal to beam axis NON_NORMAL image plane non-normal to beam axis
>>X-Ray Image Receptor Angle | (3002,000E) | 3 | X-Ray Image Receptor Angle i.e., orientation of IEC X-RAY IMAGE RECEPTOR coordinate system with respect to IEC GANTRY coordinate system (degrees). See Section C.8.8.14.3.
>>RT Image Orientation | (3002,0010) | 3 | The direction cosines of the first row and the first column with respect to the IEC X-RAY IMAGE RECEPTOR coordinate system.
>>RT Image Position | (3002,0012) | 3 | The x and y coordinates (in mm) of the upper left hand corner of the image, in the IEC X-RAY IMAGE RECEPTOR coordinate system. This is the center of the first pixel transmitted.
>>RT Image SID | (3002,0026) | 3 | Radiation machine source to image plane distance (mm).
>>Imaging Device-Specific Acquisition Parameters | (300A,00CC) | 3 | User-specified device-specific parameters that describe how the imager will acquire the image.
>>Referenced Reference Image Number | (300C,0007) | 3 | Uniquely identifies Reference Image to which planned verification image is related, specified by Reference Image Number (300A,00C8) within Referenced Reference Image Sequence (300C,0042).
>Treatment Delivery Type | (300A,00CE) | 3 | Delivery Type of treatment. Defined Terms: TREATMENT normal patient treatment OPEN_PORTFILM portal image acquisition with open field TRMT_PORTFILM portal image acquisition with treatment port CONTINUATION continuation of interrupted treatment SETUP no treatment beam is applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements are to be taken
>Referenced Dose Sequence | (300C,0080) | 3 | Related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses). One or more items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Number of Wedges | (300A,00D0) | 1 | Number of wedges associated with current Beam.
>Wedge Sequence | (300A,00D1) | 1C | Sequence of treatment wedges. Required if Number of Wedges (300A,00D0) is non-zero. One or more items shall be included in this sequence.
>>Wedge Number | (300A,00D2) | 1 | Identification number of the Wedge. The value of Wedge Number (300A,00D2) shall be unique within the Beam in which it is created.
>>Wedge Type | (300A,00D3) | 2 | Type of wedge (if any) defined for Beam. Defined Terms: STANDARD standard (static) wedge DYNAMIC moving beam limiting device (collimator) jaw simulating wedge MOTORIZED single wedge that can be removed from beam remotely
>>Wedge ID | (300A,00D4) | 3 | User-supplied identifier for Wedge.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Wedge Angle | (300A,00D5) | 2 | Nominal wedge angle (degrees).
>>Wedge Factor | (300A,00D6) | 2 | Nominal wedge factor under machine calibration conditions at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).
>>Wedge Orientation | (300A,00D8) | 2 | Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to IEC BEAM LIMITING DEVICE coordinate system (degrees).
>>Source to Wedge Tray Distance | (300A,00DA) | 3 | Radiation source to wedge tray attachment edge distance (in mm) for current wedge.
>Number of Compensators | (300A,00E0) | 1 | Number of compensators associated with current Beam.
>Total Compensator Tray Factor | (300A,00E2) | 3 | Compensator Tray transmission factor (between 0 and 1), at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).
>Compensator Sequence | (300A,00E3) | 1C | Sequence of treatment compensators. One or more items shall be included in this sequence. Required if Number of Compensators (300A,00E0) is non-zero.
>>Compensator Description | (300A,02EB) | 3 | User defined description for the compensator.
>>Compensator Number | (300A,00E4) | 1C | Identification number of the Compensator. The value of Compensator Number (300A,00E4) shall be unique within the Beam in which it is created. Required if Number of Compensators (300A,00E0) is non-zero.
>>Compensator Type | (300A,00EE) | 3 | Type of compensator (if any). Defined Terms: STANDARD physical (static) compensator DYNAMIC moving Beam Limiting Device (collimator) simulating physical compensator
>>Material ID | (300A,00E1) | 2C | User-supplied identifier for material used to manufacture Compensator. Required if Number of Compensators (300A,00E0) is non-zero.
>>Compensator ID | (300A,00E5) | 3 | User-supplied identifier for compensator.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Compensator Tray ID | (300A,00EF) | 3 | User-supplied identifier for compensator tray.
>>Source to Compensator Tray Distance | (300A,00E6) | 2 | Radiation source to compensator tray attachment edge distance (in mm) for current compensator.
>>Compensator Divergence | (300A,02E0) | 3 | Indicates presence or absence of geometrical divergence of the compensator. Enumerated Values: PRESENT the compensator is shaped according to the beam geometrical divergence. ABSENT the compensator is not shaped according to the beam geometrical divergence.
>>Compensator Mounting Position | (300A,02E1) | 3 | Indicates on which side of the Compensator Tray the compensator is mounted. Enumerated Values: PATIENT_SIDE the compensator is mounted on the side of the Compensator Tray that is towards the patient. SOURCE_SIDE the compensator is mounted on the side of the Compensator Tray that is towards the radiation source. DOUBLE_SIDED the compensator has a shaped (i.e., non-flat) surface on both sides of the Compensator Tray.
>>Compensator Rows | (300A,00E7) | 1 | Number of rows in the compensator. A row is defined to be in the X direction of the IEC Beam Limiting Device Coordinate system.
>>Compensator Columns | (300A,00E8) | 1 | Number of columns in the compensator. A column is defined to be in the Y direction of the IEC Beam Limiting Device Coordinate system.
>>Compensator Pixel Spacing | (300A,00E9) | 1 | Physical distance (in mm) between the center of each pixel projected onto machine isocentric plane. Specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing. See Section 10.7.1.3 for further explanation of the value order.
>>Compensator Position | (300A,00EA) | 1 | The x and y coordinates of the upper left hand corner (first pixel transmitted) of the compensator, projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).
>>Compensator Transmission Data | (300A,00EB) | 1C | A data stream of the pixel samples that comprise the compensator, expressed as broad-beam transmission values (between 0 and 1) along a ray line passing through the pixel, at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111). The order of pixels sent is left to right, top to bottom, i.e., the upper left pixel is sent first followed by the remainder of the first row, followed by the first pixel of the 2nd row, then the remainder of the 2nd row and so on) when viewed from the radiation source. Required if Material ID (300A,00E1) is zero-length. May be present if Material ID (300A,00E1) is non-zero length. See Section C.8.8.14.10 and Section C.8.8.14.11. ### Note Compensator Transmission Data may not be properly encoded if Explicit VR transfer syntax is used and the VL of this attribute exceeds 65534 bytes.
>>Compensator Thickness Data | (300A,00EC) | 1C | A data stream of the pixel samples that comprise the compensator, expressed as thicknesses (in mm). The order of pixels sent is left to right, top to bottom, i.e., the upper left pixel is sent first followed by the remainder of the first row, followed by the first pixel of the 2nd row, then the remainder of the 2nd row and so on) when viewed from the radiation source. Required if Material ID (300A,00E1) is non-zero length. May be present if Material ID (300A,00E1) is zero length. See Section C.8.8.14.9 and Section C.8.8.14.10 and Section C.8.8.14.11, “Block and Compensator Precedence for Dosimetric Calculations”. ### Note Compensator Thickness Data may not be properly encoded if Explicit VR transfer syntax is used and the VL of this attribute exceeds 65534 bytes.
>>Source to Compensator Distance | (300A,02E2) | 1C | A data stream of the pixel samples that comprise the distance from the radiation source to the compensator surface closest to the radiation source (in mm). The order of pixels sent is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the columns). Required if Material ID (300A,00E1) is non-zero length, and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. May be present if Material ID (300A,00E1) is zero length and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. See Section C.8.8.14.9 and Section C.8.8.14.11.
>Number of Boli | (300A,00ED) | 1 | Number of boli associated with current Beam.
>Referenced Bolus Sequence | (300C,00B0) | 1C | Sequence of boli associated with Beam. Required if Number of Boli (300A,00ED) is non-zero. One or more items shall be included in this sequence.
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies ROI representing the Bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module.
>>Bolus ID | (300A,00DC) | 3 | User-supplied identifier for the Bolus.
>>Bolus Description | (300A,00DD) | 3 | User-defined description for the Bolus.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>Number of Blocks | (300A,00F0) | 1 | Number of shielding blocks associated with Beam.
>Total Block Tray Factor | (300A,00F2) | 3 | Total block tray transmission for all block trays (between 0 and 1) at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).
>Block Sequence | (300A,00F4) | 1C | Sequence of blocks associated with Beam. One or more items shall be included in this sequence. Required if Number of Blocks (300A,00F0) is non-zero.
>>Block Tray ID | (300A,00F5) | 3 | User-supplied identifier for block tray.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Source to Block Tray Distance | (300A,00F6) | 2 | Radiation Source to attachment edge of block tray assembly (mm).
>>Block Type | (300A,00F8) | 1 | Type of block. Enumerated Values: SHIELDING blocking material is inside contour APERTURE blocking material is outside contour
>>Block Divergence | (300A,00FA) | 2 | Indicates presence or otherwise of geometrical divergence. Enumerated Values: PRESENT block edges are shaped for beam divergence ABSENT block edges are not shaped for beam divergence
>>Block Mounting Position | (300A,00FB) | 3 | Indicates on which side of the Block Tray the block is mounted. Enumerated Values: PATIENT_SIDE the block is mounted on the side of the Block Tray that is towards the patient. SOURCE_SIDE the block is mounted on the side of the Block Tray that is towards the radiation source.
>>Block Number | (300A,00FC) | 1 | Identification number of the Block. The value of Block Number (300A,00FC) shall be unique within the Beam in which it is created.
>>Block Name | (300A,00FE) | 3 | User-defined name for block.
>>Material ID | (300A,00E1) | 2 | User-supplied identifier for material used to manufacture Block.
>>Block Thickness | (300A,0100) | 2C | Physical thickness of block (in mm) parallel to radiation beam axis. Required if Material ID (300A,00E1) is non-zero length. May be present if Material ID (300A,00E1) is zero length. See Section C.8.8.14.4 and Section C.8.8.14.11.
>>Block Transmission | (300A,0102) | 2C | Transmission through the block (between 0 and 1) at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111). Required if Material ID (300A,00E1) is zero length. May be present if Material ID (300A,00E1) is non-zero length. See Section C.8.8.14.4 and Section C.8.8.14.11.
>>Block Number of Points | (300A,0104) | 2 | Number of (x,y) pairs defining the block edge.
>>Block Data | (300A,0106) | 2 | A data stream of (x,y) pairs that comprise the block edge. The number of pairs shall be equal to Block Number of Points (300A,0104), and the vertices shall be interpreted as a closed polygon. Coordinates are projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm). See Note 4.
>Applicator Sequence | (300A,0107) | 3 | Sequence of Applicators associated with Beam. Only a single item is permitted in this sequence.
>>Applicator ID | (300A,0108) | 1 | User or machine supplied identifier for Applicator.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Applicator Type | (300A,0109) | 1 | Type of Applicator. Defined Terms: ELECTRON_SQUARE square electron applicator ELECTRON_RECT rectangular electron applicator ELECTRON_CIRC circular electron applicator ELECTRON_SHORT short electron applicator ELECTRON_OPEN open (dummy) electron applicator PHOTON_SQUARE square photon applicator PHOTON_RECT rectangular photon applicator PHOTON_CIRC circular photon applicator INTRAOPERATIVE intraoperative (custom) applicator STEREOTACTIC stereotactic applicator (deprecated)
>>Applicator Geometry Sequence | (300A,0431) | 3 | Describes the applicator aperture geometry. Only a single Item is permitted in this sequence.
>>>Applicator Aperture Shape | (300A,0432) | 1 | Aperture shape of the applicator. Defined Terms: SYM_SQUARE A square-shaped aperture symmetrical to the central axis. SYM_RECTANGLE A rectangular-shaped aperture symmetrical to the central axis. SYM_CIRCULAR A circular-shaped aperture symmetrical to the central axis.
>>>Applicator Opening | (300A,0433) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system. In case of square-shaped applicator contains the length of the sides of the square. In case of circular-shaped applicators, contains the diameter of the circular aperture. Required if Applicator Aperture Shape (300A,0432) is SYM_SQUARE or SYM_CIRCULAR.
>>>Applicator Opening X | (300A,0434) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in X-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>>>Applicator Opening Y | (300A,0435) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in Y-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>> Source to Applicator Mounting Position Distance | (300A,0436) | 3 | Radiation source to applicator mounting position distance (in mm) for current applicator.
>>Applicator Description | (300A,010A) | 3 | User-defined description for Applicator.
>General Accessory Sequence | (300A,0420) | 3 | Introduces a Sequence of General Accessories associated with this Beam. One or more items are permitted in this sequence.
>>General Accessory Number | (300A,0424) | 1 | Identification Number of the General Accessory. The value shall be unique within the sequence.
>>General Accessory ID | (300A,0421) | 1 | User or machine supplied identifier for General Accessory.
>>General Accessory Description | (300A,0422) | 3 | User supplied description of General Accessory.
>>General Accessory Type | (300A,0423) | 3 | Specifies the type of accessory. Defined Terms: GRATICULE Accessory tray with a radio-opaque grid IMAGE_DETECTOR Image acquisition device positioned in the beam line RETICLE Accessory tray with radio-transparent markers or grid
>>Accessory Code | (300A,00F9) | 3 | Machine-readable identifier for this accessory
>>Source to General Accessory Distance | (300A,0425) | 3 | Radiation source to general accessory distance (in mm) for current accessory.
>Final Cumulative Meterset Weight | (300A,010E) | 1C | Value of Cumulative Meterset Weight (300A,0134) for final Control Point in Control Point Sequence (300A,0111). Required if Cumulative Meterset Weight is non-null in Control Points specified within Control Point Sequence (300A,0111). See Section C.8.8.14.1.
>Number of Control Points | (300A,0110) | 1 | Number of control points in Beam.
>Control Point Sequence | (300A,0111) | 1 | Sequence of machine configurations describing treatment beam. Two or more items shall be included in this sequence. See Section C.8.8.14.5 and Section C.8.8.14.6.
>>Control Point Index | (300A,0112) | 1 | Index of current Control Point, starting at 0 for first Control Point.
>>Cumulative Meterset Weight | (300A,0134) | 2 | Cumulative weight to current control point. Cumulative Meterset Weight for the first item in Control Point Sequence shall always be zero. Cumulative Meterset Weight for the final item in Control Point Sequence shall always be equal to Final Cumulative Meterset Weight. See Section C.8.8.14.1.
>>Referenced Dose Reference Sequence | (300C,0050) | 3 | Introduces a sequence of Dose References for current Beam. One or more items are permitted in this sequence.
>>>Referenced Dose Reference Number | (300C,0051) | 1 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module.
>>>Cumulative Dose Reference Coefficient | (300A,010C) | 2 | Coefficient used to calculate cumulative dose contribution from this Beam to the referenced Dose Reference at the current Control Point. See Section C.8.8.14.7.
>>Referenced Dose Sequence | (300C,0080) | 1C | Sequence describing related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses). One or more items shall be included in this sequence. Required if RT Dose is being sent, and Dose Summation Type (3004,000A) equals CONTROL_POINT.
>>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>>Nominal Beam Energy | (300A,0114) | 3 | Nominal Beam Energy at control point (MV/MeV).
>>Dose Rate Set | (300A,0115) | 3 | Dose Rate to be set on treatment machine for segment beginning at current control point (e.g., MU/min).
>>Wedge Position Sequence | (300A,0116) | 1C | A Sequence of Items describing Wedge Positions for the current control point. Required for first item of Control Point Sequence if Number of Wedges (300A,00D0) is non-zero, and in subsequent control points if Wedge Position (300A,0118) changes during Beam. See Section C.8.8.14.5. The number of items in this sequence shall equal the value of Number of Wedges (300A,00D0).
>>>Referenced Wedge Number | (300C,00C0) | 1 | Uniquely references Wedge described by Wedge Number (300A,00D2) in Wedge Sequence (300A,00D1).
>>>Wedge Position | (300A,0118) | 1 | Position of Wedge at current Control Point. Enumerated Values: IN OUT
>>Beam Limiting Device Position Sequence | (300A,011A) | 1C | Sequence of beam limiting device (collimator) jaw or leaf (element) positions. One or more items shall be included in this sequence. Required for first item of Control Point Sequence, or if Beam Limiting Device changes during Beam.
>>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). The value of this attribute shall correspond to RT Beam Limiting Device Type (300A,00B8) defined in an item of Beam Limiting Device Sequence (300A,00B6). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>>Leaf/Jaw Positions | (300A,011C) | 1 | Positions of beam limiting device (collimator) leaf (element) or jaw pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g., X-axis for MLCX, Y-axis for MLCY. Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC) in Beam Limiting Device Sequence (300A,00B6). Values shall be listed in IEC leaf (element) subscript order 101, 102, … 1N, 201, 202, … 2N. See Note 3.
>>Gantry Angle | (300A,011E) | 1C | Gantry angle of radiation source, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Angle changes during Beam. See Section C.8.8.14.13.
>>Gantry Rotation Direction | (300A,011F) | 1C | Direction of Gantry Rotation when viewing gantry from isocenter, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Gantry Pitch Angle | (300A,014A) | 3 | Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Angle changes during Beam, must be present. See Section C.8.8.25.6.5. See Section C.8.8.14.13.
>>Gantry Pitch Rotation Direction | (300A,014C) | 3 | Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Direction changes during Beam, must be present. See Section C.8.8.14.8 and Section C.8.8.25.6.5. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Beam Limiting Device Angle | (300A,0120) | 1C | Beam Limiting Device angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Beam Limiting Device Angle changes during Beam. See Section C.8.8.14.13.
>>Beam Limiting Device Rotation Direction | (300A,0121) | 1C | Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment following Control Point. Required for first item of Control Point Sequence, or if Beam Limiting Device Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Patient Support Angle | (300A,0122) | 1C | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Patient Support Angle changes during Beam. See Section C.8.8.14.13.
>>Patient Support Rotation Direction | (300A,0123) | 1C | Direction of Patient Support Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Patient Support Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Eccentric Axis Distance | (300A,0124) | 3 | Distance (positive) from the IEC PATIENT SUPPORT vertical axis to the IEC TABLE TOP ECCENTRIC vertical axis (mm).
>>Table Top Eccentric Angle | (300A,0125) | 1C | Table Top (non-isocentric) angle, i.e., orientation of IEC TABLE TOP ECCENTRIC coordinate system with respect to IEC PATIENT SUPPORT coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Eccentric Angle changes during Beam. See Section C.8.8.14.13.
>>Table Top Eccentric Rotation Direction | (300A,0126) | 1C | Direction of Table Top Eccentric Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Eccentric Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Pitch Angle | (300A,0140) | 1C | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.12 and Section C.8.8.14.13.
>>Table Top Pitch Rotation Direction | (300A,0142) | 1C | Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.14.12. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Roll Angle | (300A,0144) | 1C | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the IEC Y-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.12 and Section C.8.8.14.13.
>>Table Top Roll Rotation Direction | (300A,0146) | 1C | Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.14.12. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Vertical Position | (300A,0128) | 2C | Table Top Vertical position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Vertical Position changes during Beam. See Section C.8.8.14.6.
>>Table Top Longitudinal Position | (300A,0129) | 2C | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Longitudinal Position changes during Beam. See Section C.8.8.14.6.
>>Table Top Lateral Position | (300A,012A) | 2C | Table Top Lateral position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Lateral Position changes during Beam. See Section C.8.8.14.6.
>>Isocenter Position | (300A,012C) | 2C | Isocenter coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). Required for first item of Segment Control Point Sequence, or if Segment Isocenter Position changes during Beam.
>>Surface Entry Point | (300A,012E) | 3 | Patient surface entry point coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).
>>Source to Surface Distance | (300A,0130) | 3 | Source to Patient Surface distance (mm).

### Note

1. Beam Number (300A,00C0) is provided to link related information across modules, and its value should not be required to have any real-world interpretation. Beam Name (300A,00C2), a Type 3 attribute, is intended to store the primary beam identifier (often referred to as "field identifier"). Beam Description (300A,00C3), a Type 3 attribute, is intended to store additional beam identifying information (often referred to as "field name"). Equipment supporting both these attributes should state this clearly in the Conformance Statement.

2. The DICOM standard does not support the transmission of treatment unit modeling information such as depth doses and beam profiles.

3. Implementers should take note that Leaf Position Boundaries (300A,00BE) are the positions of the mechanical boundaries (projected to the isocentric plane) between beam limiting device (collimator) leaves, fixed for a given beam limiting device (collimator). Leaf/Jaw Positions (300A,011C) are values specific to a given beam control point, specifying the beam limiting device (collimator) leaf (element) openings.

4. Block coordinates may not be transmitted when such data is not available from the transmitting system. However, the receiving system may not have internal mechanisms to use or store such data. For example, a plan sent from an treatment planning system to a Record and Verify (R&V) system will contain the block data for blocked beams. Subsequent transfer of beam data from the R&V system may omit this data since the R&V system may not have stored it.

5. Refer to Section C.8.8.14.5 for examples of STATIC and DYNAMIC Beam Type. Note that beams having Wedge Type = DYNAMIC as the only moving parameter are not considered DYNAMIC according to the definition of Beam Type (300A,00C4).

6. Attributes Beam Dose Point Depth (300A,0088), Beam Dose Point Equivalent Depth (300A,0089), Beam Dose Point SSD (300A,008A) were previously included in this Module but have been retired. See PS3.3-2011.

##### C.8.8.14.1 Meterset Calculations

The Meterset at a given Control Point is equal to Beam Meterset (300A,0086) specified in the Referenced Beam Sequence (300C,0004) of the RT Fraction Scheme Module, multiplied by the Cumulative Meterset Weight (300A,0134) for the Control Point, divided by the Final Cumulative Meterset Weight (300A,010E). The Meterset is specified in units defined by Primary Dosimeter Unit (300A,00B3). If the calculation for Meterset results in a Meterset value that is not an exact multiple of the primary Meterset resolution, then the result shall be rounded to the nearest allowed Meterset value (i.e., less than a half resolution unit shall be rounded down to the nearest resolution unit, and equal or greater than half a resolution unit shall be rounded up to the nearest resolution unit).

Note also that if Final Cumulative Meterset Weight (300A,010E) is equal to 100, then Cumulative Meterset Weight (300A,0134) becomes equivalent to the percentage of Beam Meterset (300A,0086) delivered at each control point. If Final Cumulative Meterset Weight (300A,010E) is equal to Beam Meterset (300A,0086), then the Cumulative Meterset Weight (300A,0134) at each control point becomes equal to the cumulative Meterset delivered at that control point.

##### C.8.8.14.2 Planned Verification Image Sequence

The Planned Verification Image Sequence (300A,00CA) contains attributes that describe the planned verification images to be acquired during current beam. The Start Cumulative Meterset Weight (300C,0008) specifies the Cumulative Meterset Weight at which image acquisition is to begin. If Meterset Exposure (3002,0032) is present in a sequence item and End Cumulative Meterset Weight (300C,0009) is not present then a single image shall be acquired using the Meterset duration specified in Meterset Exposure (3002,0032). If End Cumulative Meterset Weight (300C,0009) is present in a sequence item and Meterset Exposure (3002,0032) is not present then a single image shall be acquired over the beam delivery from Start Cumulative Meterset Weight (300C,0008) to End Cumulative Meterset Weight (300C,0009). If both Meterset Exposure (3002,0032) and End Cumulative Meterset Weight (300C,0009) are present in a sequence item then images shall be acquired every Meterset Exposure (3002,0032) from Start Cumulative Meterset Weight (300C,0008) to End Cumulative Meterset Weight (300C,0009). No images shall extend past End Cumulative Meterset Weight (300C,0009).

##### C.8.8.14.3 X-Ray Image Receptor Angle

The X-Ray Image Receptor Angle (3002,000E) specifies the rotation of the image receptor device in the IEC X-RAY IMAGE RECEPTOR PLANE. A positive angle corresponds to a counter-clockwise rotation of the X-Ray Image Receptor as viewed from the radiation source in the IEC GANTRY coordinate system. The normal (non-rotated) value for this parameter is zero degrees.

##### C.8.8.14.4 Multiple Aperture Blocks

All blocks with Block Type (300A,00F8) of APERTURE for a given beam shall have equal values of Block Transmission (300A,0102) and/or Block Thickness (300A,0100) if they are specified. The composite aperture shall be evaluated as the union of the individual apertures within a single Block. Shielding block transmission(s) shall be applied multiplicatively after the (composite) aperture has been evaluated.

##### C.8.8.14.5 Control Point Sequence

The DICOM RT Beams Module uses a single beam model to handle static, arc, and dynamic delivery of external beam radiation by a medical accelerator or gamma beam therapy equipment (cobalt unit). All applicable parameters shall be specified at Control Point 0, with the exception of couch positions (see Section C.8.8.14.6). All parameters that change at any control point of a given beam shall be specified explicitly at all control points (including those preceding the change). No assumptions are made about the behavior of machine parameters between specified control points, and communicating devices shall agree on this behavior outside the current standard.

Gantry Rotation Direction (300A,011F), Beam Limiting Device Rotation Direction (300A,0121), Patient Support Rotation Direction (300A,0123), and Table Top Eccentric Rotation Direction (300A,0126) are defined as applying to the segment following the control point, and changes to these parameters during treatment may be specified without use of a "non-irradiation" segment. All other Control Point Sequence attributes are defined only at the control point. To unambiguously encode changes in discrete-valued attributes such as Wedge Position (300A,0118) and Nominal Beam Energy (300A,0114), a non-irradiation segment where Cumulative Meterset Weight (300A,0134) does not change, shall be used.

Some examples of beam specification using control points are as follows:

a) Static delivery:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0

Control Point 1: Cumulative Meterset Weight = 1, no other parameters defined

b) Arc delivery:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0, Gantry Rotation Direction = rotation direction, Gantry Angle = initial angle

Control Point 1: Cumulative Meterset Weight = 1, Gantry Rotation Direction = NONE, Gantry Angle = final angle

c) Dynamic delivery of two equally weighted segments:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0

Control Point 1: All changing treatment parameters defined (including those which do not change at this control point), Cumulative Meterset Weight = 0.5

Control Point 2: All changing treatment parameters defined (including those which do not change at this control point), Cumulative Meterset Weight = 1

d) Dynamic Delivery of two unequally weighted segments with a step change in table angle:

Control Point 0: All applicable treatment parameters defined, Patient Support Angle = initial angle, Patient Support Rotation Direction = NONE, Cumulative Meterset Weight = 0

Control Point 1: All changing parameters defined (including those that do not change at this control point), Cumulative Meterset Weight = 0.3, Patient Support Angle = initial angle, Patient Support Rotation Direction = rotation direction

Control Point 2: All changing parameters defined (although none should change at this control point), Cumulative Meterset Weight = 0.3, Patient Support Angle = new angle, Patient Support Rotation Direction = NONE

Control Point 3: All changing parameters defined (including those that do not change at this control point), Cumulative Meterset Weight = 1, Patient Support Angle = new angle, Patient Support Rotation Direction = NONE

##### C.8.8.14.6 Absolute and Relative Machine Coordinates

All treatment machine parameters except couch translations are specified in absolute machine coordinates as defined by IEC 61217. For the Table Top Vertical Position (300A,0128), Table Top Longitudinal Position (300A,0129), and Table Top Lateral Position (300A,012A), if the first Control Point contains a value of non-zero length, all subsequent Control Point position values are absolute values in their respective coordinate system. If the first Control Point contains a zero-length value, all subsequent Control Point position values are specified relative to the (unknown) initial value.

##### C.8.8.14.7 Cumulative Dose Reference Coefficient

The Cumulative Dose Reference Coefficient (300A,010C) is the value by which Beam Dose (300A,0084) is multiplied to obtain the dose to the referenced dose reference site at the current control point (and after previous control points have been successfully administered). The Cumulative Dose Reference Coefficient (300A,010C) is by definition zero for the initial control point. The Cumulative Dose Reference Coefficient (300A,010C) of the final control point multiplied by Beam Dose (300A,0084) results in the final dose to the referenced dose reference site for the current beam. Dose calculation for dose reference sites other than points is not well defined.

##### C.8.8.14.8 Machine Rotations

For the machine rotation angles Gantry Angle (300A,011E), Beam Limiting Device Angle (300A,0120), Patient Support Angle (300A,0122), and Table Top Eccentric Angle (300A,0125), rotation direction is specified as clockwise (CW), counter-clockwise (CC), or NONE. The maximum permitted rotation between two Control Points is 360 degrees. Examples:

1. Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = NONE:

   No movement.

2. Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = CW:

   Full clockwise rotation (360 degrees).

3. Table Angle moves from 170 degrees to 160 degrees, Table Rotation Direction = CC:

   Counter-clockwise rotation by 350 degrees (note direction of increasing table angle as defined by IEC 61217).

##### C.8.8.14.9 Compensator Thickness Data and Source to Compensator Distance

The values stored in Compensator Thickness Data (300A,00EC) and Source to Compensator Distance (300A,02E2) shall be parallel to the radiation beam axis if Compensator Divergence (300A,02E0) equals ABSENT, or divergent according to the beam geometrical divergence if Compensator Divergence (300A,02E0) equals PRESENT. If Compensator Divergence (300A,02E0) is not sent, then the parallel or divergent nature of the thicknesses is as if ABSENT was specified for Compensator Divergence (300A,02E0).

##### C.8.8.14.10 Compensator Transmission and Thickness Data Direction

The direction of the rows and columns in Compensator Transmission Data (300A,00EB) and Compensator Thickness Data (300A,00EC) is defined as follows: The direction of rows goes along the positive Xb direction and the direction of the columns does along the negative Yb direction of the IEC X-BEAM LIMITING DEVICE coordinate system. Other interpretations shall be documented in an implementation's conformance statement.

##### C.8.8.14.11 Block and Compensator Precedence for Dosimetric Calculations

If Block Thickness (300A,0100) and Block Transmission (300A,0102) are present, Block Transmission shall have precedence for dosimetric calculations. If Compensator Transmission Data (300A,00EB) and Compensator Thickness Data (300A,00EC) are present, Compensator Transmission Data shall have precedence for dosimetric calculations.

##### C.8.8.14.12 Table Top Pitch and Table Top Roll

Pitch and Roll Coordinate Systems of the Table Top are defined in IEC 61217 Edition 1.2 2008-04. These angles are defined as rotations of the IEC Table Top System as indicated below.

The Table Top Pitch Angle is defined as the rotation of the coordinate axes Yt, Zt about axis Xt by an angle ψt; See Figure C.8.8.14-1. An increase in the value of angle ψt corresponds to the clockwise rotation of the Table Top as viewed from the Table Top coordinate system origin along the positive Xt axis.

The Table Top Roll Angle is defined as the rotation of the coordinate axes Xt, Zt about axis Yt by an angle ψt; See Figure C.8.8.14-2. An increase in the value of angle ψt corresponds to the clockwise rotation of the Table Top as viewed from the Table Top coordinate system origin along the positive Yt axis.

It is important to observe that the point of rotation is the origin of the table top system after the rotation of the PATIENT SUPPORT(s) system about Zs by θs after the rotation of the Table top eccentric rotation (e) system about Ze by θe and after the translation of Table top (t) system along Xe Ye Ze. This means that the rotation point of the Pitch and Roll angles is typically not the isocenter. The translational values Xt Yt Zt may need to be adjusted to preserve the patient position at the isocenter. e.g., a rotation of the Pitch angle by a positive angle at a position originally at Xt=0, Yt=100 and Zt=0 will lead to a negative Zt value and a slightly lower Yt if the patient position at isocenter is to be maintained.

Figure C.8.8.14-1. Table Top Pitch Angle

Figure C.8.8.14-2. Table Top Roll Angle

##### C.8.8.14.13 Angular Values in RT Beams Module

The Attributes that define angles refer to coordinate systems defined by IEC 61217. Where indicated in the DICOM Attribute definition, the angle uses the coordinate system (orientation of the rotation axis and the origin of the rotating coordinate system) defined in IEC 61217, however DICOM makes no restrictions on the range of values stored. IEC 61217 defines restrictions that only apply to user interface presentation.

#### C.8.8.15 RT Brachy Application Setups Module

The RT Brachy Application Setups Module describes the application of a brachytherapy radiotherapy treatment. It contains one or more sources, each associated with one or more Channels. A Channel is a device by which a source is placed in its intended treatment position or positions. A Channel may consist of a Source Applicator plus a Transfer Tube, a Source Applicator alone, a rigid or flexible linear source, or a seed. A number of Channels (for example applicators, sources or seeds) are generally arranged in an Application Setup, which may be considered a "logical" device. It is important not to confuse Application Setup with Applicator. The model used here has been primarily built around the concept of remote afterloading, but extended to support other brachytherapy applications such as manual applicators and molds, seeds, and sources. Additional devices that are not Channels are described as Brachy Accessory Devices. Examples of Accessory Devices include shields that modify the dose distribution from all sources in the treatment. However, Channel shields modify the dose only for the source(s) in that Channel.

The data in the module are arranged as follows:

Treatment Machine Sequence | ;treatment machine information (single item)
Source Sequence | ;library of sources used in brachy application
Application Setup Sequence | ;one or more applicators, sources, seeds etc
>Brachy Accessory Device Sequence | ;application level shields etc
>Channel Sequence | ;applicator, line source(s), seed(s) etc
>>Channel Shield Sequence | ;channel-specific shields
>>Brachy Control Point Sequence | ;mechanism to support individual source dwell times

Table C.8-51. RT Brachy Application Setups Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Brachy Treatment Technique | (300A,0200) | 1 | Type of brachytherapy treatment technique. Enumerated Values: INTRALUMENARY INTRACAVITARY INTERSTITIAL CONTACT INTRAVASCULAR PERMANENT See Section C.8.8.15.1.
Brachy Treatment Type | (300A,0202) | 1 | Type of brachytherapy treatment. Defined Terms: MANUAL manually positioned HDR High dose rate MDR Medium dose rate LDR Low dose rate PDR Pulsed dose rate
Treatment Machine Sequence | (300A,0206) | 1 | Introduces single item sequence describing treatment machine to be used for treatment delivery. Only a single item shall be included in this sequence.
>Treatment Machine Name | (300A,00B2) | 2 | User-defined name identifying treatment machine to be used for treatment delivery.
>Manufacturer | (0008,0070) | 3 | Manufacturer of the equipment to be used for treatment delivery.
>Institution Name | (0008,0080) | 3 | Institution where the equipment is located that is to be used for treatment delivery.
>Institution Address | (0008,0081) | 3 | Mailing address of the institution where the equipment is located that is to be used for treatment delivery.
>Institutional Department Name | (0008,1040) | 3 | Department in the institution where the equipment is located that is to be used for treatment delivery.
>Manufacturer's Model Name | (0008,1090) | 3 | Manufacturer's model name of the equipment that is to be used for treatment delivery.
>Device Serial Number | (0018,1000) | 3 | Manufacturer's serial number of the equipment that is to be used for treatment delivery.
Source Sequence | (300A,0210) | 1 | Sequence of Sources to be used within Application Setups. One or more items shall be included in this sequence.
>Source Number | (300A,0212) | 1 | Identification number of the Source. The value of Source Number (300A,0212) shall be unique within the RT Plan in which it is created.
>Source Serial Number | (3008,0105) | 3 | Identifier for the Source Instance. Identifies the actual source instance of the source, to which Source Strength Reference Date (300A,022C) and Source Strength Reference Time (300A,022E) refer.
>Source Model ID | (300A,021B) | 3 | Identifier for the Source Model. Identifies the model, the source instance belongs to.
>Source Description | (300A,021C) | 3 | Description of the source.
>Source Type | (300A,0214) | 1 | Type of Source. Defined Terms: POINT LINE CYLINDER SPHERE
>Source Manufacturer | (300A,0216) | 3 | Manufacturer of Source.
>Active Source Diameter | (300A,0218) | 3 | Diameter of active Source (mm).
>Active Source Length | (300A,021A) | 3 | Length of active Source (mm).
>Material ID | (300A,00E1) | 3 | User-supplied identifier for encapsulation material of active Source.
>Source Encapsulation Nominal Thickness | (300A,0222) | 3 | Nominal thickness of wall of encapsulation (mm). See Section C.8.8.15.12.
>Source Encapsulation Nominal Transmission | (300A,0224) | 3 | Nominal transmission through wall of encapsulation (between 0 and 1). See Section C.8.8.15.12
>Source Isotope Name | (300A,0226) | 1 | Name of Isotope.
>Source Isotope Half Life | (300A,0228) | 1 | Half-life of Isotope (days).
>Source Strength Units | (300A,0229) | 1C | Measurement unit of Source Strength. Required if the source is not a gamma-emitting (photon) source. May be present otherwise. Enumerated Values: AIR_KERMA_RATE Air Kerma Rate if Source is Gamma emitting Isotope. DOSE_RATE_WATER Dose Rate in Water if Source is Beta emitting Isotope.
>Reference Air Kerma Rate | (300A,022A) | 1 | Air Kerma Rate in air of Isotope specified at Source Strength Reference Date (300A,022C) and Source Strength Reference Time (300A,022E) (in µGy h-1 at 1 m). Value shall be zero for non-gamma sources.
>Source Strength | (300A,022B) | 1C | Source Strength of Isotope at Source Strength Reference Date (300A,022C) and Source Strength Reference Time (300A,022E), in units specified in Source Strength Units (300A,0229). Required if the source is not a gamma-emitting (photon) source. See Section C.8.8.15.13.
>Source Strength Reference Date | (300A,022C) | 1 | Reference date for Reference Air Kerma Rate (300A,022A) or Source Strength (300A,022B) of Isotope.
>Source Strength Reference Time | (300A,022E) | 1 | Reference time for Air Kerma Rate (300A,022A) or Source Strength (300A,022B) of Isotope.
Application Setup Sequence | (300A,0230) | 1 | Sequence of Application Setups for current RT Plan. One or more items shall be included in this sequence.
>Application Setup Type | (300A,0232) | 1 | Type of Application Setup. Defined Terms: FLETCHER_SUIT DELCLOS BLOEDORN JOSLIN_FLYNN CHANDIGARH MANCHESTER HENSCHKE NASOPHARYNGEAL OESOPHAGEAL ENDOBRONCHIAL SYED_NEBLETT ENDORECTAL PERINEAL
>Application Setup Number | (300A,0234) | 1 | Identification number of the Application Setup. The value of Application Setup Number (300A,0234) shall be unique within the RT Plan in which it is created.
>Application Setup Name | (300A,0236) | 3 | User-defined name for Application Setup.
>Application Setup Manufacturer | (300A,0238) | 3 | Manufacturer of Application Setup.
>Template Number | (300A,0240) | 3 | Identification number of the Template. The value of Template Number (300A,0240) shall be unique within the Application Setup in which it is created.
>Template Type | (300A,0242) | 3 | User-defined type for Template Device.
>Template Name | (300A,0244) | 3 | User-defined name for Template Device.
>Referenced Reference Image Sequence | (300C,0042) | 3 | Sequence of reference images used for validation of current Application Setup. One or more items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Total Reference Air Kerma | (300A,0250) | 1 | Total Reference Air Kerma for current Application Setup, i.e., the product of Air Kerma Rate of all Sources in all Channels with their respective Channel Times (µGy at 1 m). Value shall be zero for non-gamma sources.
>Brachy Accessory Device Sequence | (300A,0260) | 3 | Sequence of Brachy Accessory Devices associated with current Application Setup. One or more items are permitted in this sequence.
>>Brachy Accessory Device Number | (300A,0262) | 2 | Identification number of the Brachy Accessory Device. The value of Brachy Accessory Device Number (300A,0262) shall be unique within the Application Setup in which it is created.
>>Brachy Accessory Device ID | (300A,0263) | 2 | User or machine supplied identifier for Brachy Accessory Device.
>>Brachy Accessory Device Type | (300A,0264) | 1 | Type of Brachy Accessory Device. Defined Terms: SHIELD DILATATION MOLD PLAQUE FLAB
>>Brachy Accessory Device Name | (300A,0266) | 3 | User-defined name for Brachy Accessory Device.
>>Material ID | (300A,00E1) | 3 | User-supplied identifier for material of Brachy Accessory Device. See Note.
>>Brachy Accessory Device Nominal Thickness | (300A,026A) | 3 | Nominal thickness of Brachy Accessory Device (mm). See Section C.8.8.15.12.
>>Brachy Accessory Device Nominal Transmission | (300A,026C) | 3 | Nominal Transmission through Brachy Accessory Device (between 0 and 1). See Section C.8.8.15.12.
>>Referenced ROI Number | (3006,0084) | 2 | Uniquely identifies ROI representing the Brachy Accessory specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set referenced by Referenced RT Structure Set Sequence (300C,0060) in RT General Plan Module. See Section C.8.8.15.2.
>Channel Sequence | (300A,0280) | 1 | Sequence of Channels for current Application Setup. One or more items shall be included in this sequence.
>>Channel Number | (300A,0282) | 1 | Identification number of the Channel. The value of Channel Number (300A,0282) shall be unique within the Application Setup in which it is created.
>>Channel Length | (300A,0284) | 2 | Length of Channel (mm). See Section C.8.8.15.3.
>>Channel Total Time | (300A,0286) | 1 | Total amount of time between first and final Control Points of the Brachy Control Point Sequence (300A,02D0) for current Channel (sec). Channel Total Time calculation is based upon the Reference Air Kerma Rate (300A,022A) of the Referenced Source Number (300C,000E).
>>Source Movement Type | (300A,0288) | 1 | Type of Source movement. See Section C.8.8.15.4. Defined Terms: STEPWISE FIXED OSCILLATING UNIDIRECTIONAL
>>Number of Pulses | (300A,028A) | 1C | Number of Pulses per fraction for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR.
>>Pulse Repetition Interval | (300A,028C) | 1C | Pulse repetition interval (sec) for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR.
>>Source Applicator Number | (300A,0290) | 3 | Identification number of the Source Applicator. The value of Source Applicator Number (300A,0290) shall be unique within the Channel in which it is created.
>>Source Applicator ID | (300A,0291) | 2C | User or machine supplied identifier for Source Applicator. Required if Source Applicator Number (300A,0290) is sent.
>>Source Applicator Type | (300A,0292) | 1C | Type of Source Applicator. Required if Source Applicator Number (300A,0290) is sent. Defined Terms: FLEXIBLE RIGID
>>Source Applicator Name | (300A,0294) | 3 | User-defined name for Source Applicator.
>>Source Applicator Length | (300A,0296) | 1C | Length of Source Applicator (mm), defined as the distance between the connector of the applicator and the distal-most position of the source. Required if Source Applicator Number (300A,0290) is sent.
>>Source Applicator Manufacturer | (300A,0298) | 3 | Manufacturer of Source Applicator.
>>Material ID | (300A,00E1) | 3 | User-supplied identifier for material of Source Applicator wall. See Note.
>>Source Applicator Wall Nominal Thickness | (300A,029C) | 3 | Nominal Thickness of Source Applicator wall (mm). See Section C.8.8.15.12.
>>Source Applicator Wall Nominal Transmission | (300A,029E) | 3 | Nominal Transmission through Source Applicator wall (between 0 and 1). See Section C.8.8.15.12.
>>Source Applicator Step Size | (300A,02A0) | 1C | Distance of path along channel (in mm) between adjacent (potential) dwell positions. Required if Source Movement Type (300A,0288) is STEPWISE.
>>Referenced ROI Number | (3006,0084) | 2C | Uniquely identifies ROI representing the Source Applicator specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set referenced by Referenced RT Structure Set Sequence (300C,0060) in RT General Plan Module. Required if Source Applicator Number (300A,0290) is sent. See Section C.8.8.15.2.
>>Transfer Tube Number | (300A,02A2) | 2 | Identification number of the Transfer Tube. The value of Transfer Tube Number (300A,02A2) shall be unique within the Channel in which it is created.
>>Transfer Tube Length | (300A,02A4) | 2C | Length of Transfer Tube of current afterloading Channel (mm). Required if value Transfer Tube Number (300A,02A2) is non-null.
>>Channel Shield Sequence | (300A,02B0) | 3 | Sequence of Channel Shields associated with current Channel. One or more items are permitted in this sequence. See Section C.8.8.15.5.
>>>Channel Shield Number | (300A,02B2) | 1 | Identification number of the Channel Shield. The value of Channel Shield Number (300A,02B2) shall be unique within the Channel in which it is created.
>>>Channel Shield ID | (300A,02B3) | 2 | User or machine supplied identifier for Channel Shield.
>>>Channel Shield Name | (300A,02B4) | 3 | User-defined name for Channel Shield.
>>>Material ID | (300A,00E1) | 3 | User-supplied identifier for material of Channel Shield. See Note.
>>>Channel Shield Nominal Thickness | (300A,02B8) | 3 | Nominal Thickness of Channel Shield (mm). See Section C.8.8.15.12.
>>>Channel Shield Nominal Transmission | (300A,02BA) | 3 | Nominal Transmission of Channel Shield (between 0 and 1). See Section C.8.8.15.12.
>>>Referenced ROI Number | (3006,0084) | 2 | Uniquely identifies ROI representing the Channel Shield specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set referenced by Referenced RT Structure Set Sequence (300C,0060) in RT General Plan Module. See Section C.8.8.15.2.
>>Referenced Source Number | (300C,000E) | 1 | Uniquely identifies the referenced Source within Source Sequence (300A,0210) for current Application Setup.
>>Number of Control Points | (300A,0110) | 1 | Number of control points in Channel. For an N-segment Channel there will be 2N (stepwise movement) or N+1 (continuous movement) control points.
>>Final Cumulative Time Weight | (300A,02C8) | 1C | Value of Cumulative Time Weight (300A,02D6) for final Control Point in Brachy Control Point Sequence (300A,02D0). Required if Cumulative Time Weight (300A,02D6) is non-null in Control Points specified within Brachy Control Point Sequence (300A,02D0). See Section C.8.8.15.6.
>>Brachy Control Point Sequence | (300A,02D0) | 1 | Sequence of machine configurations describing this Channel. Two or more items shall be included in this sequence. See Section C.8.8.15.7.
>>>Control Point Index | (300A,0112) | 1 | Index of current Control Point, starting at 0 for first Control Point.
>>>Cumulative Time Weight | (300A,02D6) | 2 | Cumulative time weight to current Control Point (where the weighting is proportional to time values delivered). Cumulative Time Weight for first item in Brachy Control Point Sequence (300A,02D0) is always zero. See Section C.8.8.15.6 and Section C.8.8.15.8.
>>>Control Point Relative Position | (300A,02D2) | 1 | Distance between current Control Point Position and the distal-most possible Source position in current Channel (mm). See Section C.8.8.15.9.
>>>Control Point 3D Position | (300A,02D4) | 3 | Coordinates (x, y, z) of Control Point in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). See Section C.8.8.15.10.
>>>Control Point Orientation | (300A,0412) | 3 | (x,y,z) component of the direction vector of the brachy source or seed at the Control Point 3D Position (300A,02D4). See Section C.8.8.15.14.
>>>Brachy Referenced Dose Reference Sequence | (300C,0055) | 3 | Introduces a sequence of Dose References for current Channel. One or more items are permitted in this sequence.
>>>>Referenced Dose Reference Number | (300C,0051) | 1 | Uniquely identifies Dose Reference described in Dose Reference Sequence. (300A,0010) within RT Prescription Module of current RT Plan.
>>>>Cumulative Dose Reference Coefficient | (300A,010C) | 1 | Coefficient used to calculate cumulative dose contribution from this Source to the referenced Dose Reference at the current Control Point. See Section C.8.8.15.11.

### Note

Material ID (300A,00E1) may also be specified within a referenced ROI, if an ROI is used to describe the object.

##### C.8.8.15.1 Permanent Implants

In permanent implant techniques the value for Channel Total Time (300A,0286) shall be mean life time of the isotope. The Brachy Control Point Sequence (300A,02D0) shall consist of two items: the first having Cumulative Time Weight (300A,02D6) = 0 and the second having Cumulative Time Weight (300A,02D6) = Final Cumulative Time Weight (300A,02C8).

##### C.8.8.15.2 Referenced ROI Number

The Structure Set ROI shall be used in the Brachy Application Setups Module to describe the 3D coordinates of Accessory Devices, Applicators and Channel Shields, but not individual source positions (see Section C.8.8.15.9 and Section C.8.8.15.10).

##### C.8.8.15.3 Channel Length

If specified, Channel Length (300A,0284) shall be the sum of the Source Applicator Length (300A,0296) and Transfer Tube Length (300A,02A4).

##### C.8.8.15.4 Oscillating Source Movement

In brachytherapy treatment techniques involving oscillating source movement (i.e., when Source Movement Type (300A,0288) is OSCILLATING), the Brachy Control Point Sequence (300A,02D0) shall consist of two items. The first Control Point shall have Cumulative Time Weight (300A,02D6) = 0, and Control Point Relative Position (300A,02D2) equal to one end point of the oscillation. The second Control Point shall have Cumulative Time Weight (300A,02D6) = Final Cumulative Time Weight (300A,02C8), and Control Point Relative Position (300A,02D2) equal to the other end point of the oscillation. Transit time shall not be modeled explicitly for oscillating techniques.

##### C.8.8.15.5 Channel Shields

The effect of Channel Shields on dose contributions shall be specific to the Channel for which they are specified. There shall be no effect of these shields on the dose contributions from any other Channels.

##### C.8.8.15.6 Time Calculations

The treatment time at a given Control Point is equal to the Channel Total Time (300A,0286), multiplied by the Cumulative Time Weight (300A,02D6) for the Control Point, divided by the Final Cumulative Time Weight (300A,02C8). If the calculation for treatment time results in a time value that is not an exact multiple of the timer resolution, then the result shall be rounded to the nearest allowed timer value (i.e., less than a half resolution unit shall be rounded down to the nearest resolution unit, and equal or greater than half a resolution unit shall be rounded up to the nearest resolution unit).

Note also that if Final Cumulative Time Weight (300A,02C8) is equal to 100, then Cumulative Time Weight (300A,02D6) becomes equivalent to the percentage of Channel Total Time (300A,0286) delivered at each control point. If Final Cumulative Time Weight (300A,02C8) is equal to Channel Total Time (300A,0286), then the Cumulative Time Weight (300A,02D6) at each control point becomes equal to the cumulative treatment time delivered at that control point.

If Treatment Type (300A,0202) is PDR, then the Channel Total Time (3008,0286) shall specify the duration of a single pulse.

##### C.8.8.15.7 Brachy Control Point Sequence

The Control Points shall be arranged such that the first Control Point for a particular Channel describes the first dwell position and the final Control Point for the Channel describes the final dwell position. If Brachy Treatment Type (300A,0202) is PDR, the Brachy Control Point Sequence (300A,02D0) shall specify the sequence of machine configurations for a single pulse. Similarly, if Source Movement Type (300A,0288) is OSCILLATING, the Brachy Control Point Sequence (300A,02D0) shall specify the sequence of machine configurations for a single period.

Some examples of Brachytherapy specification using control points are as follows:

a) Stepwise motion; Four equally weighted dwell positions; Step size = 10; Final Cumulative Time Weight = 100:

Control Point 0: Control Point Relative Position = 30, Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 30, Cumulative Time Weight = 25

Control Point 2: Control Point Relative Position = 20, Cumulative Time Weight = 25

Control Point 3: Control Point Relative Position = 20, Cumulative Time Weight = 50

Control Point 4: Control Point Relative Position = 10, Cumulative Time Weight = 50

Control Point 5: Control Point Relative Position = 10, Cumulative Time Weight = 75

Control Point 6: Control Point Relative Position = 0, Cumulative Time Weight = 75

Control Point 7: Control Point Relative Position = 0, Cumulative Time Weight = 100

b) Fixed (manually placed) sources; Final Cumulative Time Weight = 100:

Control Point 0: Control Point Relative Position = 0, Control Point 3D Position = (x,y,z), Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 0, Control Point 3D Position = (x,y,z), Cumulative Time Weight = 100

c) Oscillating movement; Final Cumulative Time Weight = 100:

Control Point 0: Control Point Relative Position = 100, Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 0, Cumulative Time Weight = 100

d) Unidirectional movement; Final Cumulative Time Weight = 100:

Control Point 0: Control Point Relative Position = 0, Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 100, Cumulative Time Weight = 100

e) Stepwise motion with consideration of source transit times between dwell positions; Three equally weighted dwell positions; Step size = 10; Final Cumulative Time Weight = 79:

Control Point 0: Control Point Relative Position = 30, Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 30, Cumulative Time Weight = 25

Control Point 2: Control Point Relative Position = 20, Cumulative Time Weight = 27

Control Point 3: Control Point Relative Position = 20, Cumulative Time Weight = 52

Control Point 4: Control Point Relative Position = 10, Cumulative Time Weight = 54

Control Point 5: Control Point Relative Position = 10, Cumulative Time Weight = 79

f) Stepwise motion with consideration of source transit times between dwell positions and to first and from last dwell position; Three equally weighted dwell positions; Step size = 10; Final Cumulative Time Weight = 383:

Control Point 0: Control Point Relative Position = 1200, Cumulative Time Weight = 0

Control Point 1: Control Point Relative Position = 30, Cumulative Time Weight = 150

Control Point 2: Control Point Relative Position = 30, Cumulative Time Weight = 175

Control Point 3: Control Point Relative Position = 20, Cumulative Time Weight = 177

Control Point 4: Control Point Relative Position = 20, Cumulative Time Weight = 202

Control Point 5: Control Point Relative Position = 10, Cumulative Time Weight = 204

Control Point 6: Control Point Relative Position = 10, Cumulative Time Weight = 229

Control Point 7: Control Point Relative Position = 1200, Cumulative Time Weight = 383

##### C.8.8.15.8 Source Transit Time

The Source transit times between dwell positions of a remote afterloader may be considered by specifying a non-zero increment in the Cumulative Time Weight (300A,02D6) when the Source moves between Control Points. In this case the Channel Total Time (300A,0286) shall include the overall Source transit time for the Channel.

##### C.8.8.15.9 Control Point Relative Position

Control Point Relative Position (300A,02D2) shall describe where a given source in a channel is located with respect to the end of the channel. This position shall correspond to the end of the afterloader applicator, not the "safe position".

##### C.8.8.15.10 Control Point 3D Position

Control Point 3D Position (300A,02D4) shall describe the absolute 3D coordinates of a source. This position shall correspond to the center of a source in an applicator during a remote or manually controlled afterloading treatment.

##### C.8.8.15.11 Cumulative Dose Reference Coefficient

The Cumulative Dose Reference Coefficient (300A,010C) is the value by which Brachy Application Setup Dose (300A,00A4) is multiplied to obtain the dose to the referenced dose reference site at the current control point (and after previous control points have been successfully administered). The Cumulative Dose Reference Coefficient (300A,010C) is by definition zero for the initial control point. The Cumulative Dose Reference Coefficient (300A,010C) of the final control point multiplied by Brachy Application Setup Dose (300A,00A4) results in the final dose to the referenced dose reference site for the current channel. Dose calculation for dose reference sites other than points is not well defined.

If Treatment Type (300A,0202) is PDR, then the Cumulative Dose Reference Coefficient (3008,010C) shall specify the dose delivered to the dose reference during a single pulse. The total dose delivered to the dose reference shall then be expressed by Cumulative Dose Reference Coefficient (3008,010C) multiplied by Number of Pulses (300A,028A) multiplied by Brachy Application Setup Dose (300A,00A4).

##### C.8.8.15.12 Nominal Thickness and Nominal Transmission

If provided, Source Encapsulation Nominal Thickness (300A,0222), Brachy Accessory Device Nominal Thickness (300A,026A), Source Applicator Wall Nominal Thickness (300A,029C), and Channel Shield Nominal Thickness (300A,02B8) shall indicate that the related objects are of uniform thickness with the specified value. If this is not the case, these attributes shall not be provided.

If provided, Source Encapsulation Nominal Transmission (300A,0224), Brachy Accessory Device Nominal Transmission (300A,026C), Source Applicator Wall Nominal Transmission (300A,029E), and Channel Shield Nominal Transmission (300A,02BA) shall indicate that the related objects are of uniform transmission with the specified value. If this is not the case, these attributes shall not be provided.

No assumptions are made about the source characteristics beyond the parameters specified here.

##### C.8.8.15.13 Reference Point for Calibration of Beta Emitting Isotopes

For beta emitting isotopes, Source Strength (300A,022B) shall be defined at reference point (r0,θ0), where r0 is the radial distance of 2 mm from the source longitudinal axis, and θ0 is the angle of 90 degrees between the source longitudinal axis and the line defined by the center of the source and the reference point. Refer to:

- IEC 60601-2-17 (Medical electrical equipment - Particular requirements for the safety of automatically-controlled brachytherapy afterloading equipment), where the beta source strength is defined as: ABSORBED DOSE RATE [Gy s-1] in water at 2 mm along the perpendicular bisector from a RADIOACTIVE SOURCE emitting beta RADIATION.

- Nath et. al.: Intravascular brachytherapy physics: Report of the AAPM Radiation Therapy Committee Task Group No. 60, Med. Phys 26 (2) Feb 1999, pp 119-152.

##### C.8.8.15.14 Orientation of Brachy Sources

The Control Point Orientation (300A,0412) shall be used to define the orientation of an anisotropic brachytherapy source or seed for the purpose of calculating the effect of the anisotropy on the dose calculation. The Control Point Orientation (300A,0412) shall be given by the direction vector of the long axis of the Brachy source or seed in the insertion direction, in the DICOM Patient Coordinate System. The direction vector shall be oriented from the source center as defined by the Control Point 3D Position (300A,02D4) along the long axis of the source and in the insertion direction.

#### C.8.8.16 Approval Module

Table C.8-52. Approval Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Approval Status | (300E,0002) | 1 | Approval status at the time the SOP Instance was created. Enumerated Values: APPROVED Reviewer recorded that object met an implied criterion UNAPPROVED No review of object has been recorded REJECTED Reviewer recorded that object failed to meet an implied criterion
Review Date | (300E,0004) | 2C | Date on which object was reviewed. Required if Approval Status (300E,0002) is APPROVED or REJECTED.
Review Time | (300E,0005) | 2C | Time at which object was reviewed. Required if Approval Status (300E,0002) is APPROVED or REJECTED.
Reviewer Name | (300E,0008) | 2C | Name of person who reviewed object. Required if Approval Status (300E,0002) is APPROVED or REJECTED.

#### C.8.8.17 RT General Treatment Record Module

Table C.8-53. RT General Treatment Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Instance Number | (0020,0013) | 1 | Instance number identifying this particular instance of the object.
Treatment Date | (3008,0250) | 2 | Date when current fraction was delivered, or Date last fraction was delivered in case of RT Treatment Summary Record IOD. See Note.
Treatment Time | (3008,0251) | 2 | Time when current fraction was delivered (begun), or Time last fraction was delivered (begun) in case of RT Treatment Summary Record IOD. See Note.
Referenced RT Plan Sequence | (300C,0002) | 2 | Reference to a RT Plan. Zero or one Item shall be included in this Sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Referenced Treatment Record Sequence | (3008,0030) | 3 | Reference to RT Treatment Records to which the current RT Treatment Record is significantly related. One or more Items are permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

### Note

Treatment Date (3008,0250) and Treatment Time (3008,0251) can be used to chronologically order a sequence of treatments, where each treatment is represented by an instance of a RT Beams Treatment Record or RT Brachy Treatment Record. In the case of a RT Treatment Summary Record, it can be used to identify the period for which the treatment summary is valid. Therefore, implementers are strongly advised to include values for these attributes whenever possible.

#### C.8.8.18 RT Treatment Machine Record Module

Table C.8-54. RT Treatment Machine Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Treatment Machine Sequence | (300A,0206) | 1 | Sequence describing treatment machine used for treatment delivery. Only a single Item shall be included in this Sequence.
>Treatment Machine Name | (300A,00B2) | 2 | User-defined name identifying treatment machine used for treatment delivery.
>Manufacturer | (0008,0070) | 2 | Manufacturer of the equipment used for treatment delivery.
>Institution Name | (0008,0080) | 2 | Institution where the equipment is located that was used for treatment delivery.
>Institution Address | (0008,0081) | 3 | Mailing address of the institution where the equipment is located that was used for treatment delivery.
>Institutional Department Name | (0008,1040) | 3 | Department in the institution where the equipment is located that was used for treatment delivery.
>Manufacturer's Model Name | (0008,1090) | 2 | Manufacturer's model name of the equipment used for treatment delivery.
>Device Serial Number | (0018,1000) | 2 | Manufacturer's serial number of the equipment used for treatment delivery.

#### C.8.8.19 Measured Dose Reference Record Module

Table C.8-55. Measured Dose Reference Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Measured Dose Reference Sequence | (3008,0010) | 1 | Sequence of doses measured during treatment delivery, summed over entire session. One or more Items shall be included in this sequence.
>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required only if Measured Dose Reference Number (3008,0064) is not sent. It shall not be present otherwise.
>Measured Dose Reference Number | (3008,0064) | 1C | Unique identifier of measured dose point. Required only if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>Dose Units | (3004,0002) | 1 | Units used to describe measured dose. Enumerated Values: GY Gray RELATIVE Dose relative to implicit reference value
>Measured Dose Value | (3008,0016) | 2 | Measured Dose in units specified by Dose Units (3004,0002).
>Measured Dose Type | (3008,0014) | 2 | Type of dose measurement. Defined Terms: DIODE semiconductor diode TLD thermoluminescent dosimeter ION_CHAMBER ion chamber GEL dose sensitive gel EPID electronic portal imaging device FILM dose sensitive film
>Measured Dose Description | (3008,0012) | 3 | User-defined description of Dose Reference (e.g., "Exit dose", "Point A").

#### C.8.8.20 Calculated Dose Reference Record Module

Table C.8-56. Calculated Dose Reference Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Calculated Dose Reference Sequence | (3008,0070) | 1 | Sequence of doses estimated for each treatment delivery. One or more Items shall be included in this sequence.
>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required only if Calculated Dose Reference Number (3008,0072) is not sent. It shall not be present otherwise.
>Calculated Dose Reference Number | (3008,0072) | 1C | Unique identifier of dose reference point within RT Treatment Record IOD. Required only if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>Calculated Dose Reference Dose Value | (3008,0076) | 2 | Calculated Dose (Gy).
>Calculated Dose Reference Description | (3008,0074) | 3 | User-defined description of Calculated Dose Reference.

#### C.8.8.21 RT Beams Session Record Module

Table C.8-57. RT Beams Session Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Referenced Fraction Group Number | (300C,0022) | 3 | Identifier of Fraction Group within referenced RT Plan.
Number of Fractions Planned | (300A,0078) | 2 | Total number of treatments (Fractions) planned for current Fraction Group.
Primary Dosimeter Unit | (300A,00B3) | 1 | Measurement unit of machine dosimeter. Enumerated Values: MU Monitor Unit MINUTE minute
Treatment Session Beam Sequence | (3008,0020) | 1 | Sequence of Beams administered during treatment session. One or more Items shall be included in this sequence.
>Referenced Beam Number | (300C,0006) | 3 | References Beam specified by Beam Number (300A,00C0) in Beam Sequence (300A,00B0) in RT Beams Module within referenced RT Plan.
>Beam Name | (300A,00C2) | 3 | User-defined name for delivered Beam.
>Beam Description | (300A,00C3) | 3 | User-defined description for delivered Beam.
>Beam Type | (300A,00C4) | 1 | Motion characteristic of delivered Beam. Enumerated Values: STATIC all beam parameters remain unchanged during delivery DYNAMIC one or more beam parameters changes during delivery
>Radiation Type | (300A,00C6) | 1 | Particle type of delivered Beam. Defined Terms: PHOTON ELECTRON NEUTRON PROTON
>Primary Fluence Mode Sequence | (3002,0050) | 3 | Sequence defining whether the primary fluence of the treatment beam used a non-standard fluence-shaping when the beam was delivered. Only a single item is permitted in this sequence.
>>Fluence Mode | (3002,0051) | 1 | Describes whether the fluence shaping is the standard mode for the beam or an alternate. Enumerated Values: STANDARD Uses standard fluence-shaping NON_STANDARD Uses a non-standard fluence-shaping mode
>>Fluence Mode ID | (3002,0052) | 1C | Identifier for the specific fluence-shaping mode. Required if Fluence Mode (3002,0051) has value NON_STANDARD.
>High-Dose Technique Type | (300A,00C7) | 1C | Type of high-dose treatment technique. Defined Terms: TBI Total Body Irradiation HDR High Dose Rate Required if treatment technique requires a dose that would normally require overriding of treatment machine safety controls.
>Referenced Verification Image Sequence | (300C,0040) | 3 | Sequence of verification images obtained during delivery of current beam. One or more Items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>>Start Meterset | (3008,0078) | 3 | Cumulative Meterset Weight within Beam referenced by Referenced Beam Number at which image acquisition starts.
>>End Meterset | (3008,007A) | 3 | Cumulative Meterset Weight within Beam referenced by Referenced Beam Number at which image acquisition ends.
>Referenced Measured Dose Reference Sequence | (3008,0080) | 3 | Sequence of doses measured during treatment delivery for current Beam. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely references Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Measured Dose Reference Number (3008,0082) is not sent. It shall not be present otherwise.
>>Referenced Measured Dose Reference Number | (3008,0082) | 1C | Uniquely references Measured Dose Reference specified by Measured Dose Reference Number (3008,0064) in Measured Dose Reference Sequence (3008,0010). Required if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>>Measured Dose Value | (3008,0016) | 1 | Measured Dose in units specified by Dose Units (3004,0002) in sequence referenced by Measured Dose Reference Sequence (3008,0010) or Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan as defined above.
>Referenced Calculated Dose Reference Sequence | (3008,0090) | 3 | Sequence of doses estimated for each treatment delivery. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Calculated Dose Reference Number (3008,0092) is not sent.
>>Referenced Calculated Dose Reference Number | (3008,0092) | 1C | Uniquely identifies Calculated Dose Reference specified by Calculated Dose Reference Number (3008,0072) within Calculated Dose Reference Sequence (3008,0070). Required if Referenced Dose Reference Number (300C,0051) is not sent.
>>Calculated Dose Reference Dose Value | (3008,0076) | 1 | Calculated Dose (Gy).
>Source-Axis Distance | (300A,00B4) | 3 | Radiation source to gantry rotation axis distance of the equipment that was used for beam delivery (mm).
>Beam Limiting Device Leaf Pairs Sequence | (3008,00A0) | 1 | Sequence of beam limiting device (collimator) jaw or leaf (element) leaf pair values. One or more Items shall be included in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Number of Leaf/Jaw Pairs | (300A,00BC) | 1 | Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).
>Referenced Patient Setup Number | (300C,006A) | 3 | Uniquely identifies Patient Setup used within current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence (300A,0180) of RT Treatment Record.
>Number of Wedges | (300A,00D0) | 1 | Number of wedges associated with current delivered Beam.
>Recorded Wedge Sequence | (3008,00B0) | 1C | Sequence of treatment wedges present during delivered Beam. Required if Number of Wedges (300A,00D0) is non-zero. One or more Items shall be included in this sequence.
>>Wedge Number | (300A,00D2) | 3 | Identification number of the Wedge. The value of Wedge Number (300A,00D2) shall be unique within the wedge sequence.
>>Wedge Type | (300A,00D3) | 2 | Type of wedge defined for delivered Beam. Defined Terms: STANDARD standard (static) wedge DYNAMIC moving Beam Limiting Device (collimator) jaw simulating wedge MOTORIZED single wedge that can be removed from beam remotely
>>Wedge ID | (300A,00D4) | 3 | User-supplied identifier for wedge.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Wedge Angle | (300A,00D5) | 3 | Nominal wedge angle delivered (degrees).
>>Wedge Orientation | (300A,00D8) | 3 | Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to IEC BEAM LIMITING DEVICE coordinate system (degrees).
>Number of Compensators | (300A,00E0) | 2 | Number of compensators associated with current delivered Beam.
>Recorded Compensator Sequence | (3008,00C0) | 3 | Sequence of treatment compensators associated with current Beam. One or more Items are permitted in this sequence.
>>Referenced Compensator Number | (300C,00D0) | 1 | Uniquely identifies compensator specified by Compensator Number (300A,00E4) within Beam referenced by Referenced Beam Number (300C,0006).
>>Compensator Type | (300A,00EE) | 2 | Type of compensator (if any). Defined Terms: STANDARD physical (static) compensator DYNAMIC moving Beam Limiting Device (collimator) simulating compensator
>>Compensator ID | (300A,00E5) | 3 | User-supplied identifier for compensator.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Compensator Tray ID | (300A,00EF) | 3 | User-supplied identifier for compensator tray.
>Number of Boli | (300A,00ED) | 2 | Number of boli used with current Beam.
>Referenced Bolus Sequence | (300C,00B0) | 3 | Sequence of boli associated with Beam. One or more Items are permitted in this sequence.
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies ROI representing the bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set IOD referenced by referenced RT Plan in Referenced RT Plan Sequence (300C,0002) in RT General Treatment Record Module.
>>Bolus ID | (300A,00DC) | 3 | User-supplied identifier for the Bolus.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>Number of Blocks | (300A,00F0) | 2 | Number of shielding blocks or Electron Inserts associated with Beam.
>Recorded Block Sequence | (3008,00D0) | 3 | Sequence of blocks associated with current Beam. One or more Items are permitted in this sequence.
>>Block Tray ID | (300A,00F5) | 3 | User-supplied identifier for block tray or Electron Insert.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Referenced Block Number | (300C,00E0) | 3 | Uniquely identifies block specified by Block Number (300A,00FC) within Beam referenced by Referenced Beam Number (300C,0006).
>>Block Name | (300A,00FE) | 2 | User-defined name for block.
>Applicator Sequence | (300A,0107) | 3 | Sequence of Applicators associated with Beam. Only a single item is permitted in this sequence.
>>Applicator ID | (300A,0108) | 1 | User or machine supplied identifier for Applicator.
>>Accessory Code | (300A,00F9) | 3 | An identifier for the accessory intended to be read by a device such as a bar-code reader.
>>Applicator Type | (300A,0109) | 1 | Type of Applicator. Defined Terms: ELECTRON_SQUARE square electron applicator ELECTRON_RECT rectangular electron applicator ELECTRON_CIRC circular electron applicator ELECTRON_SHORT short electron applicator ELECTRON_OPEN open (dummy) electron applicator PHOTON_SQUARE square photon applicator PHOTON_RECT rectangular photon applicator PHOTON_CIRC circular photon applicator INTRAOPERATIVE intraoperative (custom) applicator STEREOTACTIC stereotactic applicator (deprecated)
>>Applicator Geometry Sequence | (300A,0431) | 3 | Describes the applicator aperture geometry. Only a single Item is permitted in this sequence.
>>>Applicator Aperture Shape | (300A,0432) | 1 | Aperture shape of the applicator. Defined Terms: SYM_SQUARE A square-shaped aperture symmetrical to the central axis. SYM_RECTANGLE A rectangular-shaped aperture symmetrical to the central axis. SYM_CIRCULAR A circular-shaped aperture symmetrical to the central axis.
>>>Applicator Opening | (300A,0433) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system. In case of square-shaped applicator contains the length of the sides of the square. In case of circular-shaped applicators, contains the diameter of the circular aperture. Required if Applicator Aperture Shape (300A,0432) is SYM_SQUARE or SYM_CIRCULAR.
>>>Applicator Opening X | (300A,0434) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in X-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>>>Applicator Opening Y | (300A,0435) | 1C | Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in Y-Direction. Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.
>> Source to Applicator Mounting Position Distance | (300A,0436) | 3 | Radiation source to applicator mounting position distance (in mm) for current applicator.
>>Applicator Description | (300A,010A) | 3 | User-defined description for Applicator.
>General Accessory Sequence | (300A,0420) | 3 | Introduces a Sequence of General Accessories associated with this Beam. One or more items are permitted in this sequence.
>>General Accessory Number | (300A,0424) | 1 | Identification Number of the General Accessory. The value shall be unique within the sequence.
>>General Accessory ID | (300A,0421) | 1 | User or machine supplied identifier for General Accessory.
>>General Accessory Description | (300A,0422) | 3 | User supplied description of General Accessory.
>>General Accessory Type | (300A,0423) | 3 | Specifies the type of accessory. Defined Terms: GRATICULE Accessory tray with a radio-opaque grid IMAGE_DETECTOR Image acquisition device positioned in the beam line RETICLE Accessory tray with radio-transparent markers or grid
>>Accessory Code | (300A,00F9) | 3 | Machine-readable identifier for this accessory
>>Source to General Accessory Distance | (300A,0425) | 3 | Radiation source to general accessory distance (in mm) for current accessory.
>Current Fraction Number | (3008,0022) | 2 | Fraction number for this beam administration.
>Treatment Delivery Type | (300A,00CE) | 2 | Delivery Type of treatment. Defined Terms: TREATMENT Normal patient treatment OPEN_PORTFILM Portal image acquisition with open field TRMT_PORTFILM Portal image acquisition with treatment port CONTINUATION Continuation of interrupted treatment SETUP No treatment beam is applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements are to be taken. VERIFICATION Treatment used for Quality Assurance rather than patient treatment
>Treatment Termination Status | (3008,002A) | 1 | Conditions under which treatment was terminated. Enumerated Values: NORMAL treatment terminated normally OPERATOR operator terminated treatment MACHINE machine terminated treatment UNKNOWN status at termination unknown
>Treatment Termination Code | (3008,002B) | 3 | Treatment machine termination code. This code is dependent upon the particular application and equipment.
>Treatment Verification Status | (3008,002C) | 2 | Conditions under which treatment was verified by a verification system. Enumerated Values: VERIFIED treatment verified VERIFIED_OVR treatment verified with at least one out-of-range value overridden NOT_VERIFIED treatment verified manually
>Specified Primary Meterset | (3008,0032) | 3 | Desired machine setting of primary Meterset.
>Specified Secondary Meterset | (3008,0033) | 3 | Desired machine setting of secondary Meterset.
>Delivered Primary Meterset | (3008,0036) | 3 | Machine setting actually delivered as recorded by primary Meterset.
>Delivered Secondary Meterset | (3008,0037) | 3 | Machine setting actually delivered as recorded by secondary Meterset.
>Specified Treatment Time | (3008,003A) | 3 | Treatment Time set (sec).
>Delivered Treatment Time | (3008,003B) | 3 | Treatment Time actually delivered (sec).
>Number of Control Points | (300A,0110) | 1 | Number of control points delivered.
>Control Point Delivery Sequence | (3008,0040) | 1 | Sequence of beam control points for current treatment beam. One or more Items shall be included in this sequence. See Section C.8.8.21.1.
>>Referenced Control Point Index | (300C,00F0) | 3 | Uniquely identifies Control Point specified by Control Point Index (300A,0112) within Beam referenced by Referenced Beam Number (300C,0006).
>>Treatment Control Point Date | (3008,0024) | 1 | Date when the delivery of radiation at this control point began. For the final control point this shall be the Date when the previous control point ended.
>>Treatment Control Point Time | (3008,0025) | 1 | Time when the delivery of radiation at this control point began. For the final control point this shall be the Time when the previous control point ended.
>>Specified Meterset | (3008,0042) | 2 | Desired machine setting for current control point. See Section C.8.8.21.2.
>>Delivered Meterset | (3008,0044) | 1 | Machine setting actually delivered at current control point. See Section C.8.8.21.2.
>>Dose Rate Set | (300A,0115) | 2 | Dose Rate set on treatment machine for segment beginning at current control point (Meterset/min).
>>Dose Rate Delivered | (3008,0048) | 2 | Dose Rate actually delivered for segment beginning at current control point (Meterset/min).
>>Nominal Beam Energy | (300A,0114) | 3 | Nominal Beam Energy at control point.
>>Nominal Beam Energy Unit | (300A,0015) | 1C | Units used for Nominal Beam Energy (300A,0114). Required if Nominal Beam Energy (300A,0114) is sent. Defined Terms: MV Megavolt MEV Mega electron-Volt If Radiation Type (300A,00C6) is PHOTON, Nominal Beam Energy Unit (300A,0015) shall be MV. If Radiation Type (300A,00C6) is ELECTRON, Nominal Beam Energy Unit (300A,0015) shall be MEV.
>>Wedge Position Sequence | (300A,0116) | 3 | Sequence of Wedge positions for current control point. One or more Items are permitted in this sequence.
>>>Referenced Wedge Number | (300C,00C0) | 1 | Uniquely identifies wedge specified by Wedge Number (300A,00D2) within the Recorded Wedge Sequence (3008,00B0).
>>>Wedge Position | (300A,0118) | 1 | Position of Wedge at current control point. Enumerated Values: IN OUT
>>Beam Limiting Device Position Sequence | (300A,011A) | 1C | Sequence of beam limiting device (collimator) jaw or leaf (element) positions. One or more Items shall be included in this sequence. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if beam limiting device (collimator) changes during beam administration.
>>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device. The value of this attribute shall correspond to RT Beam Limiting Device Type (300A,00B8) defined in an element of Beam Limiting Device Leaf Pairs Sequence (3008,00A0). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>>Leaf/Jaw Positions | (300A,011C) | 1 | Positions of beam limiting device (collimator) leaf (element) or jaw pairs (mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g., X-axis for MLCX, Y-axis for MLCY. Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC) defined in element of Beam Limiting Device Leaf Pairs Sequence (3008,00A0). Values shall be in IEC leaf subscript order 101, 102, … 1N, 201, 202 … 2N.
>>Gantry Angle | (300A,011E) | 1C | Treatment machine gantry angle, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Gantry Angle changes during beam administration.
>>Gantry Rotation Direction | (300A,011F) | 1C | Direction of Gantry Rotation when viewing gantry from isocenter, for segment beginning at current Control Point. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040), or if Gantry Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Gantry Pitch Angle | (300A,014A) | 3 | Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Angle changes during Beam, must be present. See Section C.8.8.25.6.5.
>>Gantry Pitch Rotation Direction | (300A,014C) | 3 | Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Direction changes during Beam, must be present. See Section C.8.8.14.8 and Section C.8.8.25.6.5. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Beam Stopper Position | (3008,0230) | 3 | Position of Beam Stopper during beam administration. Enumerated Values: EXTENDED Beam Stopper extended RETRACTED Beam Stopper retracted UNKNOWN Position unknown
>>Beam Limiting Device Angle | (300A,0120) | 1C | Beam Limiting Device (collimator) angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if beam limiting device (collimator) angle changes during beam delivery.
>>Beam Limiting Device Rotation Direction | (300A,0121) | 1C | Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment beginning at current Control Point. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Beam Limiting Device Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Patient Support Angle | (300A,0122) | 1C | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Patient Support Angle changes during beam administration.
>>Patient Support Rotation Direction | (300A,0123) | 1C | Direction of Patient Support Rotation when viewing table from above, for segment beginning at current Control Point. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040), or if Patient Support Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Eccentric Axis Distance | (300A,0124) | 3 | Distance (positive) from the IEC PATIENT SUPPORT vertical axis to the IEC TABLE TOP ECCENTRIC vertical axis (mm).
>>Table Top Eccentric Angle | (300A,0125) | 1C | Table Top (non-isocentric) angle, i.e., orientation of IEC TABLE TOP ECCENTRIC coordinate system with respect to IEC PATIENT SUPPORT coordinate system (degrees). Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Table Top Eccentric Angle changes during beam administration.
>>Table Top Eccentric Rotation Direction | (300A,0126) | 1C | Direction of Table Top Eccentric Rotation when viewing table from above, for segment beginning at current Control Point. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Table Top Eccentric Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Pitch Angle | (300A,0140) | 1C | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.25.6.2.
>>Table Top Pitch Rotation Direction | (300A,0142) | 1C | Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Roll Angle | (300A,0144) | 1C | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the IEC Y-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.25.6.2.
>>Table Top Roll Rotation Direction | (300A,0146) | 1C | Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Vertical Position | (300A,0128) | 2C | Table Top Vertical position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Table Top Vertical Position changes during beam administration.
>>Table Top Longitudinal Position | (300A,0129) | 2C | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Table Top Longitudinal Position changes during beam administration.
>>Table Top Lateral Position | (300A,012A) | 2C | Table Top Lateral position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Control Point Delivery Sequence (3008,0040) or if Table Top Lateral Position changes during beam administration.
>>Corrected Parameter Sequence | (3008,0068) | 3 | Introduces a sequence of items describing any corrections made to any attributes prior to delivery of the next control point. One or more Items are permitted in this sequence.
>>>Parameter Sequence Pointer | (3008,0061) | 1 | Contains the Data Element Tag of the parent sequence containing the attribute that was corrected. The value is limited in scope to the Treatment Session Beam Sequence (3008,0020) and all nested sequences therein.
>>>Parameter Item Index | (3008,0063) | 1 | Contains the sequence item index (starting at 1) of the corrected attribute within its parent sequence.
>>>Parameter Pointer | (3008,0065) | 1 | Contains the Data Element Tag of the attribute that was corrected.
>>>Correction Value | (3008,006A) | 1 | The value applied to the attribute that was referenced by the Parameter Sequence Pointer (3008,0061), Parameter Item Index (3008,0063) and Parameter Pointer (3008,0065).
>>Override Sequence | (3008,0060) | 3 | Sequence of parameters that were overridden during the administration of the beam segment immediately prior to the current control point. One or more Items are permitted in this sequence.
>>>Override Parameter Pointer | (3008,0062) | 2 | Contains the Data Element Tag of the attribute that was overridden.
>>>Parameter Sequence Pointer | (3008,0061) | 3 | Contains the Data Element Tag of the parent sequence containing the attribute that was overridden. The value is limited in scope to the Treatment Session Beam Sequence (3008,0020) and all nested sequences therein.
>>>Parameter Item Index | (3008,0063) | 3 | Contains the sequence item index (monotonically increasing from 1) of the overridden attributes within its parent sequence. The value is limited in scope to the Treatment Session Beam Sequence (3008,0020) and all nested sequences therein.
>>>Operators' Name | (0008,1070) | 2 | Name of operator who authorized override.
>>>Override Reason | (3008,0066) | 3 | User-defined description of reason for override of parameter specified by Override Parameter Pointer (3008,0062).

##### C.8.8.21.1 Control Point Machine Delivery Parameters

All treatment machine delivery parameters (including table angles and positions) in the RT Treatment Session Record Module shall be specified as absolute, not relative, values at the Control Point.

##### C.8.8.21.2 Specified and Delivered Meterset Values

###### C.8.8.21.2.1 Beam Level

The value of Specified Primary Meterset (3008,0032) shall be the value specified by Beam Meterset (300A,0086) in the corresponding Fraction Group of the referenced RT Plan. The referenced RT Plan is found in the Referenced RT Plan Sequence (300C,0002), and within this plan the Fraction Group is found using the Referenced Fraction Group Number (300C,0022) in this module. The Beam is found in the referenced RT Plan using the Referenced Beam Number (300C,0006) in the same item of the Treatment Session Beam Sequence (3008,0020) as the Specified Primary Meterset (3008,0032).

The value of Delivered Primary Meterset (3008,0036) shall be the accumulated value of the delivered Meterset across all Control Points, which is recorded in this item of the Treatment Session Beam Sequence (3008,0020).

Note that, for example, when a partial treatment has occurred and resumption(s) have been delivered that complete delivery of all control points remaining, the sum of the Delivered Primary Meterset (3008,0036) values in all RT Beams Session Records for the beam in question and the fraction being treated will match the specified Meterset for the whole fraction.

###### C.8.8.21.2.2 Control Point Level

Specified Meterset (3008,0042) contains the MU as specified in the corresponding RT Plan at a given control point.

Delivered Meterset (3008,0044) shall contain one of the following three values:

- the Meterset value at which the delivery of the current beam started

- the Specified Meterset

- the Meterset value at which the delivery of the current beam ended

Control points that already have been treated in an earlier session shall contain the Meterset value at which the delivery of the current beam started. Control points that have been completely treated during the current session shall contain the Specified Meterset value for this Control Point. Control Points that have not yet been treated or not completely shall contain the total delivered MU up to the point where the interruption has occurred (i.e., the last control point treated).

This can be expressed by the following equation:

DelMS[CPn] = MAX (StartMS, MIN (SpecMS[CPn], EndMS))

with

DelMS[CPn]

  Delivered Meterset value at control point n

SpecMS[CPn]

  Specified Meterset value at control point n

StartMS

  Meterset value where delivery of current beam started

EndMS

  Meterset value where delivery of current beam ended

By this definition it is unambiguously recorded, which 'segments' of control points have been delivered in case of partial treatments.

Figure C.8.8.21-1. Control Point Example 1: 2 Control Points, 2 Complete Partial Treatments

Figure C.8.8.21-2. Control Point Example 1: 2 Control Points, 2 Complete Partial Treatments

Figure C.8.8.21-3. Control Point Example 3: 7 Control Points, 2 Partial Treatments with Small Gap

#### C.8.8.22 RT Brachy Session Record Module

Table C.8-58. RT Brachy Session Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Referenced Fraction Group Number | (300C,0022) | 3 | Identifier of Fraction Group within referenced RT Plan.
Number of Fractions Planned | (300A,0078) | 2 | Total number of treatments (Fractions) planned for current Fraction Group.
Brachy Treatment Technique | (300A,0200) | 1 | Type of brachytherapy treatment technique. Enumerated Values: INTRALUMENARY INTRACAVITARY INTERSTITIAL CONTACT INTRAVASCULAR PERMANENT See RT Plan IOD.
Brachy Treatment Type | (300A,0202) | 1 | Type of brachytherapy treatment. Defined Terms: MANUAL Manually positioned HDR High dose rate MDR Medium dose rate LDR Low dose rate PDR Pulsed dose rate
Recorded Source Sequence | (3008,0100) | 1 | Sequence of Sources to be used within Application Setups. One or more Items shall be included in this sequence.
>Source Number | (300A,0212) | 1 | Identification number of the Source. The value of Source Number (300A,0212) shall be unique within the Recorded Source Sequence (3008,0100) in which it is created.
>Source Type | (300A,0214) | 1 | Type of Source. Defined Terms: POINT LINE CYLINDER SPHERE
>Source Manufacturer | (300A,0216) | 2 | Manufacturer of source.
>Source Serial Number | (3008,0105) | 2 | Serial Number of source.
>Source Isotope Name | (300A,0226) | 1 | User-defined name of Isotope.
>Source Isotope Half Life | (300A,0228) | 1 | Half-life of Isotope (days).
>Source Strength Units | (300A,0229) | 1C | Measurement unit of Source Strength. Required if the source is not a gamma-emitting (photon) source. May be present otherwise. Enumerated Values: AIR_KERMA_RATE Air Kerma Rate if Source is Gamma emitting Isotope. DOSE_RATE_WATER Dose Rate in Water if Source is Beta emitting Isotope.
>Reference Air Kerma Rate | (300A,022A) | 1 | Air Kerma Rate in air of Isotope specified at Source Strength Reference Date (300A,022C) and Source Strength Reference Time (300A,022E) (in µGy h-1 at 1 m). Value shall be zero for non-gamma sources.
>Source Strength | (300A,022B) | 1C | Source Strength of Isotope at Source Strength Reference Date (300A,022C) and Source Strength Reference Time (300A,022E), in units specified in Source Strength Units (300A,0229). Required if the source is not a gamma-emitting (photon) source. See Section C.8.8.15.13.
>Source Strength Reference Date | (300A,022C) | 1 | Reference date for Reference Air Kerma Rate (300A,022A) or Source Strength (300A,022B) of Isotope.
>Source Strength Reference Time | (300A,022E) | 1 | Reference time for Air Kerma Rate (300A,022A) or Source Strength (300A,022B) of Isotope.
Treatment Session Application Setup Sequence | (3008,0110) | 1 | Sequence of Application Setups for RT Treatment Record for current RT Plan. One or more Items shall be included in this sequence.
>Application Setup Type | (300A,0232) | 1 | Type of Application Setup. Defined Terms: FLETCHER_SUIT DELCLOS BLOEDORN JOSLIN_FLYNN CHANDIGARH MANCHESTER HENSCHKE NASOPHARYNGEAL OESOPHAGEAL ENDOBRONCHIAL SYED_NEBLETT ENDORECTAL PERINEAL
>Referenced Brachy Application Setup Number | (300C,000C) | 3 | References application setup specified by Application Setup Number (300A,0234) in Application Setup Sequence (300A,0230) in RT Brachy Applications Module within referenced RT Plan.
>Application Setup Name | (300A,0236) | 3 | User-defined name for Application Setup.
>Application Setup Manufacturer | (300A,0238) | 3 | Manufacturer of Application Setup.
>Template Number | (300A,0240) | 3 | Identification number of the Template.
>Template Type | (300A,0242) | 3 | User-defined type for Template Device.
>Template Name | (300A,0244) | 3 | User-defined name for Template Device.
>Application Setup Check | (3008,0116) | 3 | Results of check-wire travel through all channels of current Application Setup. Enumerated Values: PASSED Passed check FAILED Failed check UNKNOWN Unknown status
>Referenced Verification Image Sequence | (300C,0040) | 3 | Sequence of verification images obtained during delivery of current beam. One or more Items are permitted in this sequence. See Note.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Total Reference Air Kerma | (300A,0250) | 1 | Total Reference Air Kerma for current Application Setup, i.e., the sum of the products of the Air Kerma Rates of each Source in each Channel with its respective Channel Time (µGy at 1 m). Value shall be zero for non-gamma sources.
>Referenced Measured Dose Reference Sequence | (3008,0080) | 3 | Sequence of doses measured during treatment delivery, summed over entire session. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely references Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Measured Dose Reference Number (3008,0082) is not sent. It shall not be present otherwise.
>>Referenced Measured Dose Reference Number | (3008,0082) | 1C | Uniquely references Measured Dose Reference specified by Measured Dose Reference Number (3008,0064) in Measured Dose Reference Sequence (3008,0010). Required if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>>Measured Dose Value | (3008,0016) | 1 | Measured Dose in units specified by Dose Units (3004,0002) in sequence referenced by Measured Dose Reference Sequence (3008,0010) or Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan as defined above.
>Referenced Calculated Dose Reference Sequence | (3008,0090) | 3 | Sequence of doses estimated for each treatment delivery. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Calculated Dose Reference Number (3008,0092) is not sent. It shall not be present otherwise.
>>Referenced Calculated Dose Reference Number | (3008,0092) | 1C | Uniquely identifies Calculated Dose Reference specified by Calculated Dose Reference Number (3008,0072) within Calculated Dose Reference Sequence (3008,0070). Required if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>>Calculated Dose Reference Dose Value | (3008,0076) | 1 | Calculated Dose (Gy).
>Current Fraction Number | (3008,0022) | 2 | Fraction number for this application setup.
>Treatment Delivery Type | (300A,00CE) | 2 | Delivery Type of treatment. Defined Terms: TREATMENT normal patient treatment CONTINUATION continuation of interrupted treatment
>Treatment Termination Status | (3008,002A) | 1 | Conditions under which treatment was terminated. Enumerated Values: NORMAL treatment terminated normally OPERATOR operator terminated treatment MACHINE machine terminated treatment for other than NORMAL condition UNKNOWN status at termination unknown
>Treatment Termination Code | (3008,002B) | 3 | Treatment machine termination code. This code is dependent upon the particular application and equipment.
>Treatment Verification Status | (3008,002C) | 2 | Conditions under which treatment was verified by a verification system. Enumerated Values: VERIFIED treatment verified VERIFIED_OVR treatment verified with at least one out-of-range value overridden NOT_VERIFIED treatment verified manually
>Recorded Brachy Accessory Device Sequence | (3008,0120) | 3 | Sequence of Brachy Accessory Devices associated with current Application Setup. One or more Items are permitted in this sequence.
>>Referenced Brachy Accessory Device Number | (3008,0122) | 2 | Identification number of the Brachy Accessory Device. The value of Brachy Accessory Device Number (300A,0262) shall be unique within the Application Setup in which it is created.
>>Brachy Accessory Device ID | (300A,0263) | 2 | User or machine supplied identifier for Brachy Accessory Device.
>>Brachy Accessory Device Type | (300A,0264) | 1 | Type of Brachy Accessory Device. Defined Terms: SHIELD DILATATION MOLD PLAQUE FLAB
>>Brachy Accessory Device Name | (300A,0266) | 3 | User-defined name for Brachy Accessory Device.
>Recorded Channel Sequence | (3008,0130) | 1 | Sequence of Channels for current Application Setup. One or more Items shall be included in this sequence.
>>Channel Number | (300A,0282) | 1 | Identification number of the Channel. The value of Channel Number (300A,0282) shall be unique within the Application Setup in which it is created.
>>Channel Length | (300A,0284) | 2 | Length of Channel (mm). See RT Plan IOD.
>>Specified Channel Total Time | (3008,0132) | 1 | Total amount of time in seconds, scaled for the current source delivery strength and other delivery factors, specified to be delivered at the time of treatment between the first Control Point and the final Control Point for the current Channel. In the case of resuming a partially delivered treatment, the Specified Channel Total time will only include the remainder to be treated. See Section C.8.8.22.2.
>>Delivered Channel Total Time | (3008,0134) | 1 | Total amount of time in seconds actually delivered between Control Point 0 and final Control Point of the Brachy Control Point Delivered Sequence (3008,0160) for current Channel.
>>Source Movement Type | (300A,0288) | 1 | Type of Source movement. Defined Terms: STEPWISE FIXED OSCILLATING UNIDIRECTIONAL
>>Specified Number of Pulses | (3008,0136) | 1C | Number of Pulses specified per fraction for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR. See Section C.8.8.22.1.
>>Delivered Number of Pulses | (3008,0138) | 1C | Number of Pulses actually delivered per fraction for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR. See Section C.8.8.22.1.
>>Specified Pulse Repetition Interval | (3008,013A) | 1C | Pulse repetition interval (sec) specified for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR. See Section C.8.8.22.1
>>Delivered Pulse Repetition Interval | (3008,013C) | 1C | Pulse repetition interval (sec) actually delivered for current Channel. Required if Brachy Treatment Type (300A,0202) is PDR. See Section C.8.8.22.1.
>>Referenced Measured Dose Reference Sequence | (3008,0080) | 3 | Sequence of doses measured during treatment delivery, summed over entire session. One or more Items are permitted in this sequence.
>>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely references Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Measured Dose Reference Number (3008,0082) is not sent. It shall not be present otherwise.
>>>Referenced Measured Dose Reference Number | (3008,0082) | 1C | References Measured Dose Reference specified by Measured Dose Reference Number (3008,0064) in Measured Dose Reference Sequence (3008,0010). Required if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>>>Measured Dose Value | (3008,0016) | 1 | Measured Dose.
>>Referenced Calculated Dose Reference Sequence | (3008,0090) | 3 | Sequence of doses estimated for each treatment delivery. One or more Items are permitted in this sequence.
>>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan. Required if Referenced Calculated Dose Reference Number (3008,0092) is not sent. It shall not be present otherwise.
>>>Referenced Calculated Dose Reference Number | (3008,0092) | 1C | Uniquely identifies Calculated Dose Reference specified by Calculated Dose Reference Number (3008,0072) within Calculated Dose Reference Sequence (3008,0070). Required if Referenced Dose Reference Number (300C,0051) is not sent. It shall not be present otherwise.
>>>Calculated Dose Reference Dose Value | (3008,0076) | 1 | Calculated Dose (Gy).
>>Recorded Source Applicator Sequence | (3008,0140) | 3 | Sequence of recorded Source Applicators. One or more Items are permitted in this sequence.
>>>Referenced Source Applicator Number | (3008,0142) | 2 | Identification number of the Source Applicator. The value of Source Applicator Number (300A,0290) shall be unique within the Channel in which it is created.
>>>Source Applicator ID | (300A,0291) | 2 | User or machine supplied identifier for Source Applicator.
>>>Source Applicator Type | (300A,0292) | 1 | Type of Source Applicator. Defined Terms: FLEXIBLE RIGID
>>>Source Applicator Name | (300A,0294) | 3 | User-defined name for Source Applicator.
>>>Source Applicator Length | (300A,0296) | 1 | Length of Source Applicator (mm), defined as the distance between the connector of the applicator and the distal-most position of the source.
>>>Source Applicator Manufacturer | (300A,0298) | 3 | Manufacturer of Source Applicator.
>>>Source Applicator Step Size | (300A,02A0) | 1C | Distance of path along channel (mm) between adjacent (potential) dwell positions. Required if Source Movement Type (300A,0288) is STEPWISE.
>>Transfer Tube Number | (300A,02A2) | 2 | Identification number of the Transfer Tube. The value of Transfer Tube Number (300A,02A2) shall be unique within the Channel in which it is created.
>>Transfer Tube Length | (300A,02A4) | 2C | Length of Transfer Tube of current afterloading Channel (mm). Required if value Transfer Tube Number (300A,02A2) is not zero length.
>>Recorded Channel Shield Sequence | (3008,0150) | 3 | Sequence of Channel Shields associated with current Channel. One or more Items are permitted in this sequence. See RT Plan IOD for description of Channel Shields.
>>>Referenced Channel Shield Number | (3008,0152) | 2 | Identification number of the Channel Shield. The value of Channel Shield Number (300A,02B2) shall be unique within the Channel in which it is created.
>>>Channel Shield ID | (300A,02B3) | 2 | User or machine supplied identifier for Channel Shield.
>>>Channel Shield Name | (300A,02B4) | 3 | User-defined name for Channel Shield.
>>Referenced Source Number | (300C,000E) | 1 | Uniquely identifies the referenced Source within the Recorded Source Sequence (3008,0100) for current Application Setup.
>>Safe Position Exit Date | (3008,0162) | 1C | Date on which the source(s) exited the safe. Required if Recorded Channel Sequence (3008,0130) is sent and Brachy Treatment Type (300A,0202) is not MANUAL or PDR.
>>Safe Position Exit Time | (3008,0164) | 1C | Time on which the source(s) exited the safe. Required if Recorded Channel Sequence (3008,0130) is sent and Brachy Treatment Type (300A,0202) is not MANUAL or PDR.
>>Safe Position Return Date | (3008,0166) | 1C | Date on which the source(s) returned to the safe. Required if Recorded Channel Sequence (3008,0130) is sent and Brachy Treatment Type (300A,0202) is not MANUAL or PDR.
>>Safe Position Return Time | (3008,0168) | 1C | Time on which the source(s) returned to the safe. Required if Recorded Channel Sequence (3008,0130) is sent and Brachy Treatment Type (300A,0202) is not MANUAL or PDR.
>>Number of Control Points | (300A,0110) | 1 | Number of control points in Channel. For an N-segment Channel there will be 2N (stepwise movement) or N+1 (continuous movement) control points.
>>Brachy Control Point Delivered Sequence | (3008,0160) | 1 | Sequence of machine configurations describing this Channel. Two or more items shall be included in this sequence. See RT Plan IOD and Section C.8.8.22.1 for description of Brachy Control Point Delivered Sequence.
>>>Referenced Control Point Index | (300C,00F0) | 3 | Index of current Control Point, starting at 0 for first Control Point.
>>>Treatment Control Point Date | (3008,0024) | 1 | Date when the delivery of radiation at this control point began. For the final control point this shall be the Date when the previous control point ended.
>>>Treatment Control Point Time | (3008,0025) | 1 | Time when the delivery of radiation at this control point began. For the final control point this shall be the Time when the previous control point ended.
>>>Control Point Relative Position | (300A,02D2) | 1 | Distance in mm between current Control Point Position and the distal-most possible Source position in current Channel. See RT Plan IOD.
>>>Override Sequence | (3008,0060) | 3 | Sequence of parameters that were overridden during the administration of the treatment immediately prior to the current control point. One or more Items are permitted in this sequence.
>>>>Override Parameter Pointer | (3008,0062) | 2 | Contains the Data Element Tag of the attribute that was overridden.
>>>>Operators' Name | (0008,1070) | 2 | Name of operator who authorized override.
>>>>Override Reason | (3008,0066) | 3 | User-defined description of reason for override of parameter specified by Override Parameter Pointer (3008,0062).
>>Pulse Specific Brachy Control Point Delivered Sequence | (3008,0171) | 3 | Brachy Control Point Delivered Sequence for each PDR treatment pulse. Number of items in the sequence shall be equal to the Delivered Number of Pulses (3008,0138).
>>>Pulse Number | (3008,0172) | 1 | Identification Number of this delivered Pulse. The pulse numbers for a treatment start at 1 and increase monotonically by 1. A given SOP instance might only contain some of the pulses of the given treatment.
>>>Safe Position Exit Date | (3008,0162) | 1 | Date on which the source(s) exited the safe.
>>>Safe Position Exit Time | (3008,0164) | 1 | Time at which the source(s) exited the safe.
>>>Safe Position Return Date | (3008,0166) | 1 | Date on which the source(s) returned to the safe.
>>>Safe Position Return Time | (3008,0168) | 1 | Time at which the source(s) returned to the safe.
>>>Brachy Pulse Control Point Delivered Sequence | (3008,0173) | 1 | List of control points for this pulse. See Section C.8.8.22.1.
>>>>Referenced Control Point Index | (300C,00F0) | 3 | Index of current Control Point, starting at 0 for first Control Point in this sequence.
>>>>Treatment Control Point Date | (3008,0024) | 1 | Date when the delivery of radiation at this control point began. For the final control point, this shall be the Date when the previous control point ended.
>>>>Treatment Control Point Time | (3008,0025) | 1 | Time when the delivery of radiation at this control point began. For the final control point, this shall be the Time when the previous control point ended.
>>>>Control Point Relative Position | (300A,02D2) | 1 | Distance in mm between current Control Point Position and the distal-most possible Source position in current Channel. See Section C.8.8.15.9.
>>>>Override Sequence | (3008,0060) | 3 | Parameters which were overridden during the administration of the treatment immediately prior to the current control point. One or more Items are permitted in this sequence.
>>>>>Override Parameter Pointer | (3008,0062) | 2 | Data Element Tag of the attribute that was overridden.
>>>>>Operators' Name | (0008,1070) | 2 | Name of operator who authorized override.
>>>>>Override Reason | (3008,0066) | 3 | User-defined description of reason for override.

### Note

The Referenced Verification Image Sequence (300C,0040) may contain either images taken specifically for verification of the brachy application setup or reference images used in place of verification images, as might be done in HDR treatment planning.

##### C.8.8.22.1 PDR (Pulsed Dose Rate) Treatment

In Brachytherapy treatment techniques where Brachy Treatment Type (300A,0202) is PDR, the Brachy Control Point Sequence (300A,02D0) shall consist of 2N items, where N = Delivered Number of Pulses (3008,0138). Each control point pair shall represent a single pulse and consist of the first control point of the pulse and the last control point of the pulse.

The Brachy Pulse Control Point Delivered Sequence (3008,0173) is consistent with the Brachy Control Point Delivered Sequence (3008,0160) as defined in the enclosing Recorded Channel Sequence (3008,0130) except all control points delivered are listed in this sequence as opposed to listing only the start and end control points in the Brachy Control Point Delivered Sequence (3008,0160).

##### C.8.8.22.2 Specified Channel Total Time

Total time is derived from the Brachy Control Point Sequence (300A,02D0) by scaling times for the current source delivery strength and accounting for other delivery device capabilities influencing the actual delivery.

In brachytherapy treatment techniques where Brachy Treatment Type (300A,0202) is PDR, the Specified Channel Total Time (3008,0132) shall consist of the specified channel total time summed over the Specified Number of Pulses (3008,0136).

The following examples describe the contents of Specified Channel Total Time (3008,0132), Delivered Channel Total Time (3008,0134) and Treatment Termination Status (3008,002A) under normal and interrupted delivery conditions.

Example:

- Fraction delivered without interruption

  - Session 1:

    - Specified Channel Total Time = 100.0 seconds

    - Delivered Channel Total Time = 100.0 seconds

    - Treatment Termination Status = NORMAL

- Fraction delivered with interruption. Second session delivered in timely manner such that there is negligible source decay between sessions.

  - Session 1:

    - Specified Channel Total Time = 100.0 seconds

    - Delivered Channel Total Time = 50.0 seconds

    - Treatment Termination Status = OPERATOR or MACHINE

  - Session 2:

    - Specified Channel Total Time = 50.0 seconds

    - Delivered Channel Total Time = 50.0 seconds

    - Treatment Termination Status = NORMAL

- Fraction delivered with interruption. Second session delivered later such that additional source decay between sessions must be accounted for. In Session 2 the source is at approximately 96% of Session 1 strength.

  - Session 1:

    - Specified Channel Total Time = 100.0 seconds

    - Delivered Channel Total Time = 50.0 seconds

    - Treatment Termination Status = OPERATOR or MACHINE

  - Session 2:

    - Specified Channel Total Time = 52.0 seconds

    - Delivered Channel Total Time = 52.0 seconds

    - Treatment Termination Status = NORMAL

#### C.8.8.23 RT Treatment Summary Record Module

Table C.8-59. RT Treatment Summary Record Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Current Treatment Status | (3008,0200) | 1 | Status of the Treatment at the time the Treatment Summary was created. Enumerated Values: NOT_STARTED ON_TREATMENT ON_BREAK SUSPENDED STOPPED COMPLETED See Section C.8.8.23.1.
Treatment Status Comment | (3008,0202) | 3 | Comment on current treatment status.
First Treatment Date | (3008,0054) | 2 | Date of delivery of the first treatment.
Most Recent Treatment Date | (3008,0056) | 2 | Date of delivery of the most recent administration.
Fraction Group Summary Sequence | (3008,0220) | 3 | Sequence describing current state of planned vs. delivered fraction groups. One or more Items are permitted in this sequence.
>Referenced Fraction Group Number | (300C,0022) | 3 | References Fraction Group Number (300A,0071) in Fraction Group Sequence (300A,0070) in the referenced RT Plan.
>Fraction Group Type | (3008,0224) | 2 | Indicates type of fraction group. Enumerated Values: EXTERNAL_BEAM BRACHY
>Number of Fractions Planned | (300A,0078) | 2 | Number of fractions planned for this fraction group.
>Number of Fractions Delivered | (3008,005A) | 2 | Number of fractions delivered as of Treatment Summary Report.
>Fraction Status Summary Sequence | (3008,0240) | 3 | Sequence describing status of fractions in Fraction Group. One or more Items are permitted in this sequence.
>>Referenced Fraction Number | (3008,0223) | 1 | Identifies fraction.
>>Treatment Date | (3008,0250) | 2 | Date when fraction was delivered.
>>Treatment Time | (3008,0251) | 2 | Time when fraction was delivered.
>>Treatment Termination Status | (3008,002A) | 2 | Conditions under which treatment was terminated. Enumerated Values: NORMAL treatment terminated normally OPERATOR operator terminated treatment MACHINE machine terminated treatment for other than NORMAL condition UNKNOWN status at termination unknown
Treatment Summary Measured Dose Reference Sequence | (3008,00E0) | 3 | Sequence of references to Measured Dose References. One or more Items are permitted in this sequence.
>Referenced Dose Reference Number | (300C,0051) | 3 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan referenced in Referenced RT Plan Sequence (300C,0002) of RT General Treatment Record Module.
>Dose Reference Description | (300A,0016) | 3 | User-defined description of Dose Reference.
>Cumulative Dose to Dose Reference | (3008,0052) | 1 | Cumulative Dose delivered to Dose Reference (Gy).
Treatment Summary Calculated Dose Reference Sequence | (3008,0050) | 3 | Sequence of references to Calculated Dose References. One or more Items are permitted in this sequence.
>Referenced Dose Reference Number | (300C,0051) | 3 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Plan referenced in Referenced RT Plan Sequence (300C,0002) of RT General Treatment Record Module.
>Dose Reference Description | (300A,0016) | 3 | User-defined description of Dose Reference.
>Cumulative Dose to Dose Reference | (3008,0052) | 1 | Cumulative Dose delivered to Dose Reference (Gy).

### Note

The RT Treatment Summary Record IOD may contain references to related RT Treatment Session Record IODs. These references are contained within the Referenced Treatment Record Sequence (3008,0030) of the RT General Treatment Record Module.

##### C.8.8.23.1 Current Treatment Status

Enumerated Values:

NOT_STARTED

  Patient has not yet begun treatment

ON_TREATMENT

  Patient is currently undergoing treatment

ON_BREAK

  Patient is currently not undergoing treatment, but a resumption date is known

SUSPENDED

  Patient is currently not undergoing treatment, but resumption of treatment is planned at an unknown date

STOPPED

  Patient has stopped treatment without completing the planned course

COMPLETED

  Patient completed the planned course of treatment

A change in the Current Treatment Status (or any other field) in a RT Treatment Summary Record Object shall define a new instance of the RT Treatment Summary Record IOD.

#### C.8.8.24 RT Ion Tolerance Tables Module

The RT Ion Tolerance Tables Module contains information describing the maximum allowed differences between the planned and measured attributes for Ion therapy.

Table C.8.8.24-1. RT Ion Tolerance Tables Module Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Ion Tolerance Table Sequence | (300A,03A0) | 1 | Sequence of ion tolerance tables to be used for delivery of treatment plan. One or more items shall be included in this sequence. See Note 1.
>Tolerance Table Number | (300A,0042) | 1 | Identification number of the Tolerance Table. The value of Tolerance Table Number (300A,0042) shall be unique within the RT Ion Plan in which it is created.
>Tolerance Table Label | (300A,0043) | 3 | User-defined label for Tolerance Table.
>Gantry Angle Tolerance | (300A,0044) | 3 | Maximum permitted difference (in degrees) between planned and delivered Gantry Angle.
>Beam Limiting Device Angle Tolerance | (300A,0046) | 3 | Maximum permitted difference (in degrees) between planned and delivered Beam Limiting Device Angle.
>Beam Limiting Device Tolerance Sequence | (300A,0048) | 3 | Sequence of beam limiting device (collimator) tolerances. One or more items are permitted in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Beam Limiting Device Position Tolerance | (300A,004A) | 1 | Maximum permitted difference (in mm) between planned and delivered leaf (element) or jaw positions for current beam limiting device (collimator).
>Patient Support Angle Tolerance | (300A,004C) | 3 | Maximum permitted difference (in degrees) between planned and delivered Patient Support Angle.
>Table Top Vertical Position Tolerance | (300A,0051) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Vertical Position.
>Table Top Longitudinal Position Tolerance | (300A,0052) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Longitudinal Position.
>Table Top Lateral Position Tolerance | (300A,0053) | 3 | Maximum permitted difference (in mm) between planned and delivered Table Top Lateral Position.
>Table Top Pitch Angle Tolerance | (300A,004F) | 3 | Maximum permitted difference (in degrees) between planned and delivered Table Top Pitch Angle.
>Table Top Roll Angle Tolerance | (300A,0050) | 3 | Maximum permitted difference (in degrees) between planned and delivered Table Top Roll Angle.
>Snout Position Tolerance | (300A,004B) | 3 | Maximum permitted difference (in mm) between planned and delivered Snout Position.

Note 1: Tolerance Tables may be used to compare planned values to actual machine values. If the absolute difference between the planned and actual values exceeds the Tolerance Table value, treatment may be inhibited or the operator may be warned.

#### C.8.8.25 RT Ion Beams Module

The RT Ion Beams Module contains information defining equipment parameters for delivery of external Ion radiation beams.

Table C.8.8.25-1. RT Ion Beams Module Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Ion Beam Sequence | (300A,03A2) | 1 | Sequence of setup and/or treatment beams for current RT Ion Plan. One or more items shall be included in this sequence.
>Beam Number | (300A,00C0) | 1 | Identification number of the Beam. The value of Beam Number (300A,00C0) shall be unique within the RT Ion Plan in which it is created. See Section C.8.8.25.1.
>Beam Name | (300A,00C2) | 1 | User-defined name for Beam. See Section C.8.8.25.1.
>Beam Description | (300A,00C3) | 3 | User-defined description for Beam. See Section C.8.8.25.1.
>Beam Type | (300A,00C4) | 1 | Motion characteristic of Beam. Enumerated Values: STATIC all beam parameters remain unchanged during delivery DYNAMIC one or more beam parameters changes during delivery
>Radiation Type | (300A,00C6) | 1 | Particle type of Beam. Defined Terms: PHOTON PROTON ION
>Radiation Mass Number | (300A,0302) | 1C | Mass number of radiation. Required if Radiation Type (300A,00C6) is ION
>Radiation Atomic Number | (300A,0304) | 1C | Atomic number of radiation. Required if Radiation Type (300A,00C6) is ION
>Radiation Charge State | (300A,0306) | 1C | Charge state of radiation. Required if Radiation Type (300A,00C6) is ION
>Scan Mode | (300A,0308) | 1 | The method of beam scanning to be used during treatment. Defined Terms: NONE No beam scanning is performed. UNIFORM The beam is scanned between control points to create a uniform lateral fluence distribution across the field. MODULATED The beam is scanned between control points to create a modulated lateral fluence distribution across the field.
>Treatment Machine Name | (300A,00B2) | 2 | User-defined name identifying treatment machine to be used for beam delivery. See Section C.8.8.25.2.
>Manufacturer | (0008,0070) | 3 | Manufacturer of the equipment to be used for beam delivery.
>Institution Name | (0008,0080) | 3 | Institution where the equipment is located that is to be used for beam delivery.
>Institution Address | (0008,0081) | 3 | Mailing address of the institution where the equipment is located that is to be used for beam delivery.
>Institutional Department Name | (0008,1040) | 3 | Department in the institution where the equipment is located that is to be used for beam delivery.
>Manufacturer's Model Name | (0008,1090) | 3 | Manufacturer's model name of the equipment that is to be used for beam delivery.
>Device Serial Number | (0018,1000) | 3 | Manufacturer's serial number of the equipment that is to be used for beam delivery.
>Primary Dosimeter Unit | (300A,00B3) | 1 | Measurement unit of machine dosimeter. Enumerated Values: MU Monitor Unit NP number of particles
>Referenced Tolerance Table Number | (300C,00A0) | 3 | Uniquely identifies Tolerance Table specified by Tolerance Table Number (300A,0042) within Tolerance Table Sequence in RT Ion Tolerance Tables Module. These tolerances are to be used for verification of treatment machine settings.
>Virtual Source-Axis Distances | (300A,030A) | 1 | Distance (in mm) from virtual source position to gantry rotation axis or nominal isocenter position (fixed beam-lines) of the equipment to be used for beam delivery. Specified by a numeric pair - the VSAD in the IEC Gantry X direction followed by the VSAD in the IEC Gantry Y direction. The VSAD is commonly used for designing apertures in contrast to the effective source-axis-distance (ESAD) that is commonly used with the inverse square law for calculating the dose decrease with distance. See Section C.8.8.25.4.
>Ion Beam Limiting Device Sequence | (300A,03A4) | 3 | Sequence of beam limiting device (collimator) jaw or leaf (element) sets. One or more items are permitted in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Isocenter to Beam Limiting Device Distance | (300A,00BB) | 2 | Isocenter to beam limiting device (collimator) distance (in mm) of the equipment that is to be used for beam delivery. See Section C.8.8.25.4.
>>Number of Leaf/Jaw Pairs | (300A,00BC) | 1 | Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).
>>Leaf Position Boundaries | (300A,00BE) | 1C | Boundaries of beam limiting device (collimator) leaves (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), i.e., X-axis for MLCY, Y-axis for MLCX. Contains N+1 values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), starting from Leaf (Element) Pair 1. Required if RT Beam Limiting Device Type (300A,00B8) is MLCX or MLCY. May be present otherwise. See Section C.8.8.25.3.
>Referenced Patient Setup Number | (300C,006A) | 3 | Uniquely identifies Patient Setup to be used for current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence of RT Patient Setup Module.
>Referenced Reference Image Sequence | (300C,0042) | 3 | Reference images used for validation of current beam. One or more items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>>Reference Image Number | (300A,00C8) | 1 | Uniquely identifies Reference Image within Referenced Reference Image Sequence (300C,0042).
>Treatment Delivery Type | (300A,00CE) | 1 | Delivery Type of treatment. Defined Terms: TREATMENT Normal patient treatment OPEN_PORTFILM Portal image acquisition with open field (the source of radiation is specified by Radiation Type (300A,00C6)) TRMT_PORTFILM Portal image acquisition with treatment port (the source of radiation is specified by Radiation Type (300A,00C6)) CONTINUATION Continuation of interrupted treatment SETUP No treatment beam is applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements shall be taken.
>Referenced Dose Sequence | (300C,0080) | 3 | Related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses). One or more items are permitted in this sequence.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” | The Referenced Class SOP UID shall be that of the RT Dose SOP Class (1.2.840.10008.5.1.4.1.1.481.2.
>Number of Wedges | (300A,00D0) | 1 | Number of wedges associated with current beam.
>Total Wedge Tray Water-Equivalent Thickness | (300A,00D7) | 3 | Shift of the wedge tray induced on the range of the ion beam as measured in water (in mm).
>Ion Wedge Sequence | (300A,03AA) | 1C | Sequence of treatment wedges. Required if Number of Wedges (300A,00D0) is non-zero. The number of items shall be identical to the value of Number of Wedges (300A,00D0).
>>Wedge Number | (300A,00D2) | 1 | Identification number of the Wedges. The value of Wedge Number (300A,00D2) shall be unique within the Beam in which it was created.
>>Wedge Type | (300A,00D3) | 2 | Type of wedge (if any) defined for Beam. Defined Terms: STANDARD standard (static) wedge MOTORIZED single wedge that can be removed from beam remotely. PARTIAL_STANDARD wedge does not extend across the whole field and is operated manually. PARTIAL_MOTORIZ wedge does not extend across the whole field and can be removed from beam remotely.
>>Wedge ID | (300A,00D4) | 3 | User-supplied identifier for Wedge.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Wedge Angle | (300A,00D5) | 2 | Nominal wedge angle (degrees).
>>Wedge Orientation | (300A,00D8) | 2 | Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to the IEC BEAM LIMITING DEVICE coordinate systems (degrees).
>>Isocenter to Wedge Tray Distance | (300A,00D9) | 1 | Isocenter to downstream edge of wedge tray (mm). See Section C.8.8.25.4
>Number of Compensators | (300A,00E0) | 1 | Number of compensators associated with current Beam.
>Total Compensator Tray Water-Equivalent Thickness | (300A,02E3) | 3 | Water-Equivalent thickness of the compensator tray (in mm) parallel to radiation beam axis.
>Ion Range Compensator Sequence | (300A,02EA) | 1C | Sequence of compensators. Required if Number of Compensators (300A,00E0) is non-zero. The number of items shall be identical to the value of Number of Compensators (300A,00E0).
>>Compensator Description | (300A,02EB) | 3 | User defined description for the compensator.
>>Compensator Number | (300A,00E4) | 1 | Identification number of the Compensator. The value of Compensator Number (300A,00E4) shall be unique within the Beam in which it is created.
>>Material ID | (300A,00E1) | 2 | User-supplied identifier for material used to manufacture Compensator.
>>Compensator ID | (300A,00E5) | 3 | User-supplied identifier for the compensator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Isocenter to Compensator Tray Distance | (300A,02E4) | 1C | Isocenter to compensator tray attachment edge distance (in mm) for current range compensator. Required if Compensator Mounting Position (300A,02E1) is not DOUBLE_SIDED. See Section C.8.8.25.4
>>Compensator Divergence | (300A,02E0) | 1 | Indicates presence or absence of geometrical divergence of the range compensator. Enumerated Values: PRESENT the range compensator is shaped according to the beam geometrical divergence. ABSENT the range compensator is not shaped according to the beam geometrical divergence.
>>Compensator Mounting Position | (300A,02E1) | 1 | Indicates on which side of the Compensator Tray the compensator is mounted. Enumerated Values: PATIENT_SIDE the Compensator is mounted on the side of the Compensator Tray that is towards the patient. SOURCE_SIDE the Compensator is mounted on the side of the Compensator Tray that is towards the radiation source. DOUBLE_SIDED the Compensator has a shaped (i.e., non-flat) surface on both sides of the Compensator Tray.
>>Compensator Rows | (300A,00E7) | 1 | Number of rows in the range compensator. A row is defined to be in the X direction of the IEC Beam Limiting Device Coordinate system.
>>Compensator Columns | (300A,00E8) | 1 | Number of columns in the range compensator. A column is defined to be in the Y direction of the IEC Beam Limiting Device Coordinate system.
>>Compensator Pixel Spacing | (300A,00E9) | 1 | Physical distance (in mm) between the center of each pixel projected onto machine isocentric plane. Specified by a numeric pair - adjacent row spacing followed by adjacent column spacing. See Section 10.7.1.3 for further explanation of the value order.
>>Compensator Position | (300A,00EA) | 1 | The x and y coordinates of the upper left hand corner (first pixel transmitted) of the range compensator, projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).
>>Compensator Column Offset | (300A,02E5) | 1C | The offset distance (in mm) applied to the x coordinate of Compensator Position (300A,00EA) for even numbered rows. Required if the compensator pattern is hexagonal.
>>Compensator Thickness Data | (300A,00EC) | 1 | A data stream of the pixel samples that comprise the range compensator, expressed as physical thickness (in mm), either parallel to radiation beam axis if Compensator Divergence (300A,02E0) equals ABSENT, or divergent according to the beam geometrical divergence if Compensator Divergence (300A,02E0) equals PRESENT. The order of pixels sent is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the rows).
>>Isocenter to Compensator Distances | (300A,02E6) | 1C | A data stream of the pixel samples that comprise the distance from the isocenter to the compensator surface closest to the radiation source (in mm). The order of pixels sent is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the rows). Required if Material ID (300A,00E1) is non-zero length, and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. See Section C.8.8.14.9 and Section C.8.8.25.4.
>>Compensator Relative Stopping Power Ratio | (300A,02E7) | 3 | Compensator Linear Stopping Power Ratio, relative to water, at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Ion Control Point Sequence (300A,03A8).
>>Compensator Milling Tool Diameter | (300A,02E8) | 3 | The diameter (in mm) of the milling tool to be used to create the compensator. The diameter is expressed as the actual physical size and not a projected size at isocenter.
>Number of Boli | (300A,00ED) | 1 | Number of boli associated with current Beam.
>Referenced Bolus Sequence | (300C,00B0) | 1C | Sequence of boli associated with Beam. Required if Number of Boli (300A,00ED) is non-zero. The number of items shall be identical to the value of Number of Boli (300A,00ED).
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies ROI representing the Bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Number of Blocks | (300A,00F0) | 1 | Number of shielding blocks associated with Beam.
>Total Block Tray Water-Equivalent Thickness | (300A,00F3) | 3 | Water-Equivalent thickness of the block tray (in mm) parallel to radiation beam axis.
>Ion Block Sequence | (300A,03A6) | 1C | Sequence of blocks associated with Beam. Required if Number of Blocks (300A,00F0) is non-zero. The number of items shall be identical to the value of Number of Blocks (300A,00F0).
>>Block Tray ID | (300A,00F5) | 3 | User-supplied identifier for block tray.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Isocenter to Block Tray Distance | (300A,00F7) | 1 | Isocenter to downstream edge of block tray (mm). See Section C.8.8.25.4
>>Block Type | (300A,00F8) | 1 | Type of block. See Section C.8.8.14.4. Enumerated Values: SHIELDING blocking material is inside contour APERTURE blocking material is outside contour
>>Block Divergence | (300A,00FA) | 1 | Indicates presence or otherwise of geometrical divergence. Enumerated Values: PRESENT block edges are shaped for beam divergence ABSENT block edges are not shaped for beam divergence
>>Block Mounting Position | (300A,00FB) | 1 | Indicates on which side of the Block Tray the block is mounted. Enumerated Values: PATIENT_SIDE the block is mounted on the side of the Block Tray that is towards the patient SOURCE_SIDE the block is mounted on the side of the Block Tray that is towards the radiation source
>>Block Number | (300A,00FC) | 1 | Identification number of the Block. The value of Block Number (300A,00FC) shall be unique within the Beam in which it is created.
>>Block Name | (300A,00FE) | 3 | User-defined name for block.
>>Material ID | (300A,00E1) | 2 | User-supplied identifier for material used to manufacture Block.
>>Block Thickness | (300A,0100) | 1 | Physical thickness of block (in mm) parallel to radiation beam axis. See Section C.8.8.14.4.
>>Block Number of Points | (300A,0104) | 1 | Number of (x,y) pairs defining the block edge.
>>Block Data | (300A,0106) | 1 | A data stream of (x,y) pairs that comprise the block edge. The number of pairs shall be equal to Block Number of Points (300A,0104), and the vertices shall be interpreted as a closed polygon. Coordinates are projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).
>Snout Sequence | (300A,030C) | 3 | Sequence of Snouts associated with Beam. Only a single item is permitted in this sequence.
>>Snout ID | (300A,030F) | 1 | User or machine supplied identifier for Snout.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Applicator Sequence | (300A,0107) | 3 | Sequence of Applicators associated with Beam. Only a single item is permitted in this sequence.
>>Applicator ID | (300A,0108) | 1 | User or machine supplied identifier for Applicator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Applicator Type | (300A,0109) | 1 | Type of applicator. Defined Terms: ION_SQUARE square ion applicator ION_RECT rectangular ion applicator ION_CIRC circular ion applicator ION_SHORT short ion applicator ION_OPEN open (dummy) ion applicator INTRAOPERATIVE intraoperative (custom) applicator STEREOTACTIC stereotactic applicator
>>Applicator Description | (300A,010A) | 3 | User-defined description for Applicator.
>General Accessory Sequence | (300A,0420) | 3 | Introduces a Sequence of General Accessories associated with this Beam. One or more items are permitted in this sequence.
>>General Accessory Number | (300A,0424) | 1 | Identification Number of the General Accessory. The value shall be unique within the sequence.
>>General Accessory ID | (300A,0421) | 1 | User or machine supplied identifier for General Accessory.
>>General Accessory Description | (300A,0422) | 3 | User supplied description of General Accessory.
>>General Accessory Type | (300A,0423) | 3 | Specifies the type of accessory. Defined Terms: GRATICULE Accessory tray with a radio-opaque grid IMAGE_DETECTOR Image acquisition device positioned in the beam line RETICLE Accessory tray with radio-transparent markers or grid
>>Accessory Code | (300A,00F9) | 3 | Machine-readable identifier for this accessory
>>Source to General Accessory Distance | (300A,0425) | 3 | Radiation source to general accessory distance (in mm) for current accessory.
>Number of Range Shifters | (300A,0312) | 1 | Number of range shifters associated with current beam.
>Range Shifter Sequence | (300A,0314) | 1C | Sequence of range shifters associated with Beam. Required if Number of Range Shifters (300A,0312) is non-zero. The number of items shall be identical to the value of Number of Range Shifters (300A,0312).
>>Range Shifter Number | (300A,0316) | 1 | Identification number of the Range Shifter. The value of Range Shifter Number (300A,0316) shall be unique within the Beam in which it is created.
>>Range Shifter ID | (300A,0318) | 1 | User or machine supplied identifier for Range Shifter.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Range Shifter Type | (300A,0320) | 1 | Type of Range Shifter. Defined Terms: ANALOG Device is variable thickness and is composed of opposing sliding wedges, water column or similar mechanism. BINARY Device is composed of different thickness materials that can be moved in or out of the beam in various stepped combinations.
>>Range Shifter Description | (300A,0322) | 3 | User defined description of Range Shifter.
>Number of Lateral Spreading Devices | (300A,0330) | 1 | Number of lateral spreading devices associated with current beam.
>Lateral Spreading Device Sequence | (300A,0332) | 1C | Sequence of lateral spreading devices associated with Beam. Required if Number of Lateral Spreading Devices (300A,0330) is non-zero. The number of items shall be identical to the value of Number of Lateral Spreading Devices (300A,0330).
>>Lateral Spreading Device Number | (300A,0334) | 1 | Identification number of the Lateral Spreading Device. The value of Lateral Spreading Device Number (300A,0334) shall be unique within the Beam in which it is created.
>>Lateral Spreading Device ID | (300A,0336) | 1 | User or machine supplied identifier for Lateral Spreading Device.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Lateral Spreading Device Type | (300A,0338) | 1 | Type of Lateral Spreading Device. Defined Terms: SCATTERER metal placed into the beam path to scatter charged particles laterally. MAGNET nozzle configuration of magnet devices to expand beam laterally.
>>Lateral Spreading Device Description | (300A,033A) | 3 | User-defined description for lateral spreading device.
>Number of Range Modulators | (300A,0340) | 1 | Number of range modulators associated with current beam.
>Range Modulator Sequence | (300A,0342) | 1C | Sequence of range modulators associated with Beam. Required if Number of Range Modulators (300A,0340) is non-zero. The number of items shall be identical to the value of Number of Range Modulators (300A,0340).
>>Range Modulator Number | (300A,0344) | 1 | Identification number of the Range Modulator. The value of Range Modulator Number (300A,0344) shall be unique within the Beam in which it is created.
>>Range Modulator ID | (300A,0346) | 1 | User or machine supplied identifier for Range Modulator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Range Modulator Type | (300A,0348) | 1 | Type of Range Modulator. Defined Terms: FIXED fixed modulation width and weights using ridge filter or constant speed wheel with constant beam current WHL_FIXEDWEIGHTS selected wheel/track (Range Modulator ID) is spinning at constant speed. Modulation width is adjusted by switching constant beam current on and off at wheel steps indicated by Range Modulator Gating Values. WHL_MODWEIGHTS selected wheel/track (Range Modulator ID) is spinning at constant speed. Weight per wheel step is adjusted by modulating beam current according to selected Beam Current Modulation ID (300A,034C). Only one item in the Range Modulator Sequence (300A,0342) can have a Range Modulator Type (300A,0348) of WHL_MODWEIGHTS.
>>Range Modulator Description | (300A,034A) | 3 | User-defined description of Range Modulator.
>>Beam Current Modulation ID | (300A,034C) | 1C | User-supplied identifier for the beam current modulation pattern. Required if Range Modulator Type (300A,0348) is WHL_MODWEIGHTS
>Include Table C.8.8.28-1 “Patient Support Identification Macro Attributes” |
>Fixation Light Azimuthal Angle | (300A,0356) | 3 | Azimuthal angle (degrees) of the fixation light coordinate around IEC BEAM LIMITING DEVICE Y-axis. Used for eye treatments. See Section C.8.8.25.6.4.
>Fixation Light Polar Angle | (300A,0358) | 3 | Polar angle (degrees) of the fixation light coordinate. Used for eye treatments. See Section C.8.8.25.6.4.
>Final Cumulative Meterset Weight | (300A,010E) | 1C | Value of Cumulative Meterset Weight (300A,0134) for final Control Point in Ion Control Point Sequence (300A,03A8). Required if Cumulative Meterset Weight is non-null in Control Points specified within Ion Control Point Sequence. See Section C.8.8.14.1.
>Number of Control Points | (300A,0110) | 1 | Number of control points in Beam. Value shall be greater than or equal to 2.
>Ion Control Point Sequence | (300A,03A8) | 1 | Sequence of machine configurations describing Ion treatment beam. The number of items shall be identical to the value of Number of Control Points (300A,0110). See Section C.8.8.25.7.
>>Control Point Index | (300A,0112) | 1 | Index of current Control Point, starting at 0 for first Control Point.
>>Cumulative Meterset Weight | (300A,0134) | 2 | Cumulative weight to current control point. Cumulative Meterset Weight for the first item in Control Point Sequence shall always be zero. Cumulative Meterset Weight for the final item in Ion Control Point Sequence shall always be equal to Final Cumulative Meterset Weight.
>>Referenced Dose Reference Sequence | (300C,0050) | 3 | Introduces a sequence of Dose References for current Beam. One or more items are permitted in this sequence.
>>>Referenced Dose Reference Number | (300C,0051) | 1 | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module.
>>>Cumulative Dose Reference Coefficient | (300A,010C) | 2 | Coefficient used to calculate cumulative dose contribution from this Beam to the referenced Dose Reference at the current Control Point.
>>Nominal Beam Energy | (300A,0114) | 1C | Nominal Beam Energy at control point in MeV per nucleon. Defined at nozzle entrance before all Beam Modifiers. Required for first item of Control Point Sequence, or if Nominal Beam Energy changes during Beam, and KVP (0018,0060) is not present.
>>KVP | (0018,0060) | 1C | Peak kilo voltage output of the setup X-Ray generator to be used. Required for first item of Control Point Sequence, or if kVp changes during setup, and Nominal Beam Energy (300A,0114) is not present.
>>Meterset Rate | (300A,035A) | 3 | Specifies the speed of delivery of the specified dose in units specified by Primary Dosimeter Unit (300A,00B3) per minute.
>>Ion Wedge Position Sequence | (300A,03AC) | 1C | Sequence of Wedge positions for current control point. Required for first item of Ion Control Point Sequence if Number of Wedges (300A,00D0) is non-zero, and in subsequent control points if Wedge Position (300A,0118) or Wedge Thin Edge Position (300A,00DB) changes during beam. The number of items shall be identical to the value of Number of Wedges (300A,00D0).
>>>Referenced Wedge Number | (300C,00C0) | 1 | Uniquely references Wedge described by Wedge Number (300A,00D2) in Wedge Sequence (300A,00D1).
>>>Wedge Position | (300A,0118) | 1 | Position of Wedge at current Control Point. Enumerated Values: IN OUT
>>>Wedge Thin Edge Position | (300A,00DB) | 1C | Closest distance from the central axis of the beam along a wedge axis to the thin edge as projected to the machine isocentric plane (mm). Value is positive is the wedge does not cover the central axis, negative if it does. Required if Wedge Type (300A,00D3) of the wedge referenced by Referenced Wedge Number (300C,00C0) is PARTIAL_STANDARD or PARTIAL_MOTORIZ. See Section C.8.8.25.6.4.
>>Range Shifter Settings Sequence | (300A,0360) | 1C | Sequence of Range Shifter settings for the current control point. One or more items shall be included in this sequence. Required for first item of Control Point Sequence if Number of Range Shifters (300A,0312) is non-zero, or if Range Shifter Setting (300A,0362) changes during Beam.
>>>Referenced Range Shifter Number | (300C,0100) | 1 | Uniquely references Range Shifter described by Range Shifter Number (300A,0316) in Range Shifter Sequence (300A,0314).
>>>Range Shifter Setting | (300A,0362) | 1 | Machine specific setting attribute for the range shifter. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.
>>>Isocenter to Range Shifter Distance | (300A,0364) | 3 | Isocenter to downstream edge of range shifter (mm) at current control point. See Section C.8.8.25.4
>>>Range Shifter Water Equivalent Thickness | (300A,0366) | 3 | Water equivalent thickness (in mm) of the range shifter at the central axis for the beam energy incident upon the device.
>>Lateral Spreading Device Settings Sequence | (300A,0370) | 1C | Sequence of Lateral Spreading Device settings for the current control point. One or more items shall be included in this sequence. Required for first item of Control Point Sequence if Number of Lateral Spreading Devices (300A,0330) is non-zero, or if Lateral Spreading Device Setting (300A,0372) changes during Beam.
>>>Referenced Lateral Spreading Device Number | (300C,0102) | 1 | Uniquely references Lateral Spreading Device described by Lateral Spreading Device Number (300A,0334) in Lateral Spreading Device Sequence (300A,0332).
>>>Lateral Spreading Device Setting | (300A,0372) | 1 | Machine specific setting attribute for the lateral spreading device. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.
>>>Isocenter to Lateral Spreading Device Distance | (300A,0374) | 3 | Isocenter to downstream edge of Lateral Spreading Device (mm) at current control point. See Section C.8.8.25.4
>>>Lateral Spreading Device Water Equivalent Thickness | (300A,033C) | 3 | Water equivalent thickness (in mm) of the lateral spreading device at the central axis for the beam energy incident upon the device.
>>Range Modulator Settings Sequence | (300A,0380) | 1C | Sequence of Range Modulator Settings for current control point. One or more items shall be included in this sequence. Required for first item of Control Point Sequence if Number of Range Modulators (300A,0340) is non-zero, or if Range Modulator Setting changes during Beam.
>>>Referenced Range Modulator Number | (300C,0104) | 1 | Uniquely references Range Modulator described by Range Modulator Number (300A,0344) in Range Modulator Sequence (300A,0342).
>>>Range Modulator Gating Start Value | (300A,0382) | 1C | Start position defines the range modulator position at which the beam is switched on. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS
>>>Range Modulator Gating Stop Value | (300A,0384) | 1C | Stop position defines the range modulator position at which the beam is switched off. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS
>>>Range Modulator Gating Start Water Equivalent Thickness | (300A,0386) | 3 | If Range Modulator Type (300A,0348) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS: Water equivalent thickness (in mm) of the range modulator at the position specified by Range Modulator Gating Start Value (300A,0382). If Range Modulator Type (300A,0348) is FIXED: Minimum water equivalent thickness (in mm) of the range modulator.
>>>Range Modulator Gating Stop Water Equivalent Thickness | (300A,0388) | 3 | If Range Modulator Type (300A,0348) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS: Water equivalent thickness (in mm) of the range modulator at the position specified by Range Modulator Gating Stop Value (300A,0384). If Range Modulator Type (300A,0348) is FIXED: Maximum water equivalent thickness (in mm) of the range modulator.
>>>Isocenter to Range Modulator Distance | (300A,038A) | 3 | Isocenter to downstream edge of range modulator (mm) at current control point. See Section C.8.8.25.4
>>Include Table C.8.8.27-1 “Beam Limiting Device Position Macro Attributes” |
>>Gantry Angle | (300A,011E) | 1C | Gantry angle of radiation source, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Angle changes during Beam.
>>Gantry Rotation Direction | (300A,011F) | 1C | Direction of Gantry Rotation when viewing gantry from isocenter, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Gantry Pitch Angle | (300A,014A) | 2C | Gantry Pitch Angle of the radiation source, i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Angle changes during Beam. See Section C.8.8.25.6.5.
>>Gantry Pitch Rotation Direction | (300A,014C) | 2C | Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.5. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Beam Limiting Device Angle | (300A,0120) | 1C | Beam Limiting Device angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Beam Limiting Device Angle changes during Beam.
>>Beam Limiting Device Rotation Direction | (300A,0121) | 1C | Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment following Control Point. Required for first item of Control Point Sequence, or if Beam Limiting Device Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Scan Spot Tune ID | (300A,0390) | 1C | User-supplied or machine code identifier for machine configuration to produce beam spot. This may be the nominal spot size or some other machine specific value. Required if Scan Mode (300A,0308) is MODULATED.
>>Number of Scan Spot Positions | (300A,0392) | 1C | Number of spot positions used to specify scanning pattern for current segment beginning at control point. Required if Scan Mode (300A,0308) is MODULATED.
>>Scan Spot Position Map | (300A,0394) | 1C | The x and y coordinates of the scan spots are defined as projected onto the machine isocentric plane in the IEC GANTRY coordinate system (mm). Required if Scan Mode (300A,0308) is MODULATED. Contains 2N values where N is the Number of Scan Spot Positions (300A,0392).
>>Scan Spot Meterset Weights | (300A,0396) | 1C | A data set of Meterset weights corresponding to scan spot positions. The order of weights matches the positions in Scan Spot Positions (300A,0394). The sum contained in all Meterset weights shall match the difference of the cumulative Meterset weight of the current control point to the following control point. Required if Scan Mode (300A,0308) is MODULATED.
>>Scanning Spot Size | (300A,0398) | 3 | The Scanning Spot Size as calculated using the Full Width Half Maximum (FWHM). Specified by a numeric pair - the size measured in air at isocenter in IEC GANTRY X direction followed by the size in the IEC GANTRY Y direction (mm).
>>Number of Paintings | (300A,039A) | 1C | The number of times the scan pattern given by Scan Spot Position Map (300A,0394) and Scan Spot Meterset Weights (300A,0396) shall be applied at the current control point. To obtain the Meterset weight per painting, the values in the Scan Spot Meterset Weights (300A,0396) should be divided by the value of this attribute. Required if Scan Mode (300A,0308) is MODULATED.
>>Patient Support Angle | (300A,0122) | 1C | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Patient Support Angle changes during Beam.
>>Patient Support Rotation Direction | (300A,0123) | 1C | Direction of Patient Support Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Patient Support Rotation Direction changes during Beam. See Section C.8.8.14.8. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Pitch Angle | (300A,0140) | 2C | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Pitch Angle changes during Beam. See Section C.8.8.25.6.2.
>>Table Top Pitch Rotation Direction | (300A,0142) | 2C | Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Roll Angle | (300A,0144) | 2C | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Roll Angle changes during Beam. See Section C.8.8.25.6.2.
>>Table Top Roll Rotation Direction | (300A,0146) | 2C | Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Roll Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation.
>>Head Fixation Angle | (300A,0148) | 3 | Angle (in degrees) of the head fixation for eye treatments with respect to the Table Top Pitch Angle (300A,0140) coordinate system. Positive head fixation angle is the same direction as positive Table Top pitch. See Section C.8.8.25.6.4.
>>Table Top Vertical Position | (300A,0128) | 2C | Table Top Vertical position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Vertical Position changes during Beam. See Section C.8.8.14.6.
>>Table Top Longitudinal Position | (300A,0129) | 2C | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Longitudinal Position changes during Beam. See Section C.8.8.14.6.
>>Table Top Lateral Position | (300A,012A) | 2C | Table Top Lateral position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Lateral Position changes during Beam. See Section C.8.8.14.6.
>>Snout Position | (300A,030D) | 2C | Axial position of the snout (in mm) measured from isocenter to the downstream side of the snout (without consideration of variable length elements such as blocks, MLC and/or compensators). Required for first item in Control Point Sequence, or if Snout Position changes during Beam.
>>Isocenter Position | (300A,012C) | 2C | Isocenter coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). Required for first item of Segment Control Point Sequence, or if Segment Isocenter Position changes during Beam.
>>Surface Entry Point | (300A,012E) | 3 | Patient surface entry point coordinates (x,y,z), along the central axis of the beam, in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).

##### C.8.8.25.1 Beam Identifying Information

Beam Number (300A,00C0) is provided to link related information across modules, and its value has no real-world interpretation. Beam Name (300A,00C2), a Type 1 attribute, is intended to store the primary beam identifier (often referred to as "Field ID"). Beam Description (300A,00C3), a Type 3 attribute, is intended to store additional beam identifying information (often referred to as "Field Name").

##### C.8.8.25.2 Treatment Machine Name

The DICOM standard does not support the transmission of treatment unit modeling information such as depth doses and beam profiles. In the case of Ion therapy, the Treatment Machine Name attribute is used to uniquely identify a treatment port (or beam line), since there is in effect only one treatment machine (i.e., synchrotron).

##### C.8.8.25.3 Leaf Position Boundaries

The Leaf Position Boundaries (300A,00BE) shall be the positions of the mechanical boundaries (projected to the isocentric plane) between beam limiting device (collimator) leaves, fixed for a given beam limiting device (collimator). Leaf/Jaw positions (300A,011C) are values specific to a given control point, specifying the beam limiting device (collimator) leaf (element) openings.

In an RT Ion Plan, the Virtual SAD can have different values along the X/Y axes (see Section C.8.8.25.4). Thus the effects of possibly different X/Y SADs shall be taken into account when leaf position boundaries and leaf/jaw positions are projected from the virtual source to the plane of isocenter.

Leaf Position Boundaries (300A,00BE), are outside the control point sequence, which may define a collimator rotation. Therefore their values shall be defined for a collimator angle of 0 Deg IEC nominal position). For rotated collimators, the leaf position calculation is as follows: Define Mx and My as the magnification factors for the scaling of the leaf positions from their real space position to the isocenter plane. Mx and My are calculated from the virtual SADs VSADx or VSADy, respectively, and the Isocenter to Beam Limiting Device Distance (300A,00BB).

The magnification factor Mα for an arbitrary beam limiting device angle a then becomes:

Snout Position (300A,030D) may be changed between beams, and possibly between control points as well. This results in different effective isocenter to beam limiting device distances and thus leaf position boundaries for the same physical beam limiting device for each beam and possibly control points.

The values for Beam Limiting Device Distances (300A,00BB) and Leaf Position Boundaries (300A,00BE) are defined outside the control point sequence. Therefore the Isocenter to Beam Limiting Device Distance (300A,00BB) and the Leaf Position Boundaries (300A,00BE) shall be defined to apply to the first control point of the respective beam. If the snout position changes for subsequent control points, this must be taken into account for the projection of the leaf/jaw positions (i.e., replace IsocenterToBeamLimitingDeviceDistance in the above formula by the effective distance as calculated from the shift in snout position).

##### C.8.8.25.4 Virtual Source-Axis Distances and the Use of Trays in Ion Therapy

The apparent source position in ion therapy is not constant or can be different in x or y direction. The apparent source position (as measured from field size projections) shall be called Virtual Source, the distance from the virtual source to isocenter the Virtual SAD.

Most of the cases, no trays are used for blocks, compensators and wedges. However, the concept of trays together with the mounting position is useful for specifying exactly at which point the position of these devices shall be measured. Therefore, trays shall always be sent, even though they are only virtual trays.

Figure C.8.8.25-1 shows an example.

Figure C.8.8.25-1. Virtual Source-Axis Distances

Examples: The use of the above attributes for snout positioning and block/compensator manufacturing:

1. Snout positioning:

   The mounting positions as depicted in the drawing are only examples. As the block tray does not really exist in most of the cases, it is only used as a reference position. As some machines use the downstream face of the block as a reference position for their snout positioning, it could make sense to define for example that the block mounting position must be SOURCE_SIDE. In this case, one uses the downstream face of the block as the reference position, which is the same side as used by the machine. This definition is always independent of the actual thickness of the block. The Isocenter-Block Distance is defined and the machine can deduce the position of the snout from this value.

2. Scaling of block/compensator data for manufacturing

   The Isocenter position is always used as the reference position for all distances measured 'from isocenter'. Real size block and compensator manufacturing should be based on the distance from the Virtual Source (X/Y) to the device, i.e., VirtualSourceToDeviceDistance = VirtualSAD - IsocenterToDeviceDistance.

##### C.8.8.25.5 Range Shifter and Lateral Spreading Device Settings

The Range Shifter and Lateral Spreading Device Settings attributes are used to capture machine specific values related to these devices. For example, some machines may specify the Range Shifter setting as the desired Water-Equivalent Thickness (in mm). Others contain a series of interchangeable plates, whose position in or out of the beam is specified by a series of ones and zeros (i.e., 100010 would specify that plates #1 and #5 are in the beam. If the device does not a specific setting, but rather is defined by the ID, then the Enumerated Values IN/OUT shall be used for the setting.

##### C.8.8.25.6 Coordinate Systems

Where explicitly specified, the coordinate systems defined by IEC 61217 shall be applied, with the exception of the IEC Patient Coordinate System.

In addition, the following sections define the coordinate systems to be used in situations where IEC 61217 coordinate systems are not applicable. No other coordinate systems shall be used.

###### C.8.8.25.6.1 Fixed Beam Line

The direction of fixed beam-line can be described as a gantry system, provided that the position of the (virtual) gantry bearing is defined. The relation between their patient support coordinate system axes and the choice of the 'gantry' angle, e.g., 90 or 270 deg, shall be consistent with a standard gantry coordinate system. All coordinate systems derived from the IEC GANTRY coordinate system (BEAM LIMITING DEVICE, WEDGE, X-RAY IMAGE RECEPTOR) automatically follow in the same way as defined in a 'real' gantry system.

The IEC PATIENT SUPPORT system is linked to the IEC GANTRY coordinate system through its common parent system, the IEC FIXED coordinate system. The Y-axis of IEC GANTRY points towards the (virtual) gantry bearing. The Y-axis of the IEC FIXED coordinate system has to point in the same direction. Z-axis in IEC FIXED coordinate system is always pointing upwards. With Y and Z-axes defined, the X-axis of IEC FIXED is also given.

Figure C.8.8.25-2a and Figure C.8.8.25-2b show IEC FIXED (F), GANTRY (G) and PATIENT SUPPORT (S) coordinate systems for a horizontal fixed beam-line.

Figure C.8.8.25-2a. Fixed Beam Line - View Along IEC FIXED Y-axis

Figure C.8.8.25-2b. Fixed Beam Line - View From Top (Along IEC FIXED Z-axis)

###### C.8.8.25.6.2 Table Top Pitch and Table Top Roll

For further information, see Section C.8.8.14.12.

###### C.8.8.25.6.3 Seated Treatments

RT Ion Plan contains an attribute Patient Support Type (300A,0350), which can be CHAIR or TABLE. The patient support type CHAIR does not change the coordinate axes of the patient support coordinate systems relative to their parent systems. It is more an attribute of the type like the patient position in imaging (i.e., HFS, HFP, …).

The orientation of the treatment chair shall be defined with the chair positioned in such way, that the patient looks towards the gantry bearing (or along the Y axis of the IEC FIXED system) if all angles, especially IEC PATIENT SUPPORT angle are 0°. All other parameters follow straight forward, once this definition is accepted. i.e., chair rotation is a rotation of IEC PATIENT SUPPORT coordinate system; a backward tilt of the chair is a positive rotation of the PITCHED TABLE TOP coordinate system. A translation of the chair is a translation of the IEC TABLE TOP system.

The roll angle is typically 0º.

For a seated treatment on a horizontal beam-line, the following angles are therefore defined:If IEC GANTRY angle is 90º (270º), IEC PATIENT SUPPORT angle is 270º (90º) for the position where the patient looks into the beam port.

###### C.8.8.25.6.4 Ocular Treatments

###### C.8.8.25.6.4.1 Gantry Beam Line

Eye treatments on the gantry shall use all existing IEC coordinate systems with their standard definition. This applies especially to IEC BEAM LIMITING DEVICE, IEC WEDGE FILTER, IEC X-RAY IMAGE RECEPTOR.

IEC PATIENT SUPPORT, and IEC TABLE TOP coordinate systems are defined as above. Additionally, a rotation of the head fixation device is possible. The Head Fixation Angle (300A,0148) shall be defined as the angle of the head fixation device with respect to the TABLE TOP coordinate system. Positive head fixation angle is in the same direction as positive PATIENT SUPPORT pitch, i.e., backwards.

Proton eye treatments require an additional coordinate system for the placement of the fixation light. Since it is usually mounted onto the beam port the 'natural' coordinate system for devices mounted there is the IEC BEAM LIMITING DEVICE coordinate system. The angles for the fixation light positions shall therefore be defined as follows:

Rotation of the fixation light about the IEC BEAM LIMITING DEVICE Z-axis (Zb) is defined as Azimuthal Angle. The Azimuthal Angle is equal to 0° when the fixation light is positioned on the axis Xb of the IEC BEAM LIMITING DEVICE coordinate system. An increase in the value of the Azimuthal Angle corresponds to clockwise rotation of the fixation light as view along the axis Zb towards the virtual source.

The polar angle is always positive and defined as the angle between IEC BEAM LIMITING DEVICE Z-axis and the line connecting isocenter with the fixation light position.

Proton eye treatments require the wedge thin edge position as one additional. The wedge thin edge position allows the specification of a wedge, which does not cover the full open field. The wedge thin edge position is positive, if the wedge does not cover the isocenter position and negative, if it does cover.

Figure C.8.8.25-5 and Figure C.8.8.25-6 show the angles and attributes as described above.

Figure C.8.8.25-5. Patient's eye view

Figure C.8.8.25-6. Lateral view along the positive axis Xb

###### C.8.8.25.6.4.2 Fixed Beam Line

The coordinate systems for the treatment chair are defined above and shall also be applied to seated eye treatments.

In this case, it is recommended that a beam limiting device angle of 90º be formally applied (provided the gantry angle is defined to be 90º (and not 270º). This results in the same coordinates of the fixation light and wedge relative to the patient as in the treatment situation with the patient lying on the table.

###### C.8.8.25.6.5 Gantry Pitch Angle

The Gantry Pitch Angle is not defined in IEC 61217. This angle is defined in the DICOM standard in a way compatible with the current notion of IEC by introducing it as rotation of the IEC GANTRY System as indicated below.

The Gantry Pitch Angle is defined as the rotation of the coordinate axes Yg, Zg about axis Xg by an angle ψg; See Figure C.8.8.25-7. An increase in the value of angle ψg corresponds to the clockwise rotation as viewed from the isocenter along the positive Xg axis

Figure C.8.8.25-7. Gantry Pitch Angle

##### C.8.8.25.7 Ion Control Point Sequence

The control point sequence for RT Ion Beams is defined using the same rule set as in the RT Beams module (see Section C.8.8.14.5). Specifically, the following rules apply:

- All parameters that change at any control point of a given beam shall be specified explicitly at all control points (including those preceding the change).

- All parameters of an irradiation segment (i.e., with values of the Cumulative Meterset Weight (300A,0134) different at the beginning and at the end of the segment) shall therefore be specified in 2 separate control points denoting the beginning and at the end of this segment. Each irradiation segment is therefore represented by 2 control points.

- Parameters changing during the segment shall be represented by their different values at those control points. Parameters that do not change during the segment shall be represented with equal values at both control points (unless they are constant for all control points of the beam). For example, a beam delivery involving two independent irradiation segments will require 4 control points. Control Points 0 and 1 define the first irradiation segment. Between control points 1 and 2, no radiation is given (Meterset is constant), but other parameters may change. Finally, the second irradiation segment occurs between control points 2 and 3.

This definition allows unambiguous and explicit determination of those parameters changing while irradiation is occurring, as opposed to those parameters that change between irradiation segments. No assumptions are made about the behavior of machine parameters between specified control points, and communicating devices shall agree on this behavior outside the standard.

The following example illustrates this rule (not all parameters are shown), in the case of a scanning beam with 2 segments and Total Cumulative Meterset of 70.

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0 Nominal Energy: 200 Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1st segment) Scan Spot Meterset Weight: 0.5, 0.3, 1.2, (Values add up to Meterset difference between Control Points 0 and 1)

Control Point 1: All applicable treatment parameters defined, Cumulative Meterset Weight = 30.0 Nominal Energy: 200 Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1st segment) Scan Spot Meterset Weight:0.0, 0.0, 0.0, … (All values are 0.0, because Meterset Weight difference between Control Point 1 and 2 is 0.0)

Control Point 2: All applicable treatment parameters defined, Cumulative Meterset Weight = 30.0 Nominal Energy: 180 Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2nd segment) Spot Meterset Weight: 0.7, 0.8, 1.5 (Values add up to Meterset difference between Control Points 2 and 3)

Control Point 3: All applicable treatment parameters defined, Cumulative Meterset Weight = 70.0 Nominal Energy: 180 Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2nd segment) Spot Meterset Weight: 0.0, 0.0, 0.0, (All values are 0.0, because there is no following control point (end of sequence).

#### C.8.8.26 RT Ion Beams Session Record Module

Table C.8.8.26-1 specifies the Attributes that describe the measured and recorded settings acquired during Ion Radiation Treatments.

Table C.8.8.26-1. RT Ion Beams Session Record Module Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Referenced Fraction Group Number | (300C,0022) | 3 | Identifier of fraction group within referenced RT Ion Plan.
Number of Fractions Planned | (300A,0078) | 2 | Total number of treatments (fractions) planned for current fraction group.
Primary Dosimeter Unit | (300A,00B3) | 1 | Measurement unit of the machine dosimeter. Enumerated Values: MU Monitor Units NP Number of Particles
Treatment Session Ion Beam Sequence | (3008,0021) | 1 | Sequence of setup and/or treatment beams administered during treatment session. One or more items shall be included in this sequence.
>Referenced Beam Number | (300C,0006) | 1 | References Beam specified by Beam Number (300A,00C0) in Ion Beam Sequence (300A,03A2) in RT Ion Beams Module within the referenced RT Ion Plan.
>Beam Name | (300A,00C2) | 1 | User-defined name for Beam. See Section C.8.8.25.1.
>Beam Description | (300A,00C3) | 3 | User-defined description for Beam. See Section C.8.8.25.1.
>Beam Type | (300A,00C4) | 1 | Motion characteristic of Beam. Enumerated Values: STATIC all beam parameters remain unchanged during delivery DYNAMIC one or more beam parameters changes during delivery
>Radiation Type | (300A,00C6) | 1 | Particle type of Beam. Defined Terms: PHOTON PROTON ION
>Radiation Mass Number | (300A,0302) | 1C | Mass number of radiation. Required if Radiation Type (300A,00C6) is ION
>Radiation Atomic Number | (300A,0304) | 1C | Atomic number of radiation. Required if Radiation Type (300A,00C6) is ION
>Radiation Charge State | (300A,0306) | 1C | Charge state of radiation. Required if Radiation Type (300A,00C6) is ION
>Scan Mode | (300A,0308) | 1 | The method of beam scanning used during treatment. Defined Terms: NONE No beam scanning is performed. UNIFORM The beam is scanned between control points to create a uniform lateral fluence distribution across the field. MODULATED The beam is scanned between control points to create a modulated lateral fluence distribution across the field.
>Referenced Tolerance Table Number | (300C,00A0) | 3 | Uniquely identifies Ion Tolerance Table specified by Tolerance Table Number (300A,0042) within Ion Tolerance Table Sequence in RT Ion Tolerance Tables Module. These tolerances are to be used for verification of treatment machine settings.
>Beam Limiting Device Leaf Pairs Sequence | (3008,00A0) | 3 | Sequence of beam limiting device (collimator) jaw or leaf (element) sets. One or more items are permitted in this sequence.
>>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>>Number of Leaf/Jaw Pairs | (300A,00BC) | 1 | Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).
>Referenced Patient Setup Number | (300C,006A) | 3 | Uniquely identifies Ion Patient Setup to be used for current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence of RT Patient Setup Module.
>Referenced Verification Image Sequence | (300C,0040) | 3 | Sequence of verification images obtained during delivery of current beam. One or more items are permitted in this sequence. See Section C.8.8.14.2.
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Referenced Measured Dose Reference Sequence | (3008,0080) | 3 | Sequence of doses measured during treatment delivery for current Beam. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely references Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Ion Plan. Required if Referenced Measured Dose Reference Number (3008,0082) is not sent.
>>Referenced Measured Dose Reference Number | (3008,0082) | 1C | Uniquely references Measured Dose Reference specified by Measured Dose Reference Number (3008,0064) in Measured Dose Reference Sequence (3008,0010). Required if Referenced Dose Reference Number (300C,0051) is not sent.
>>Measured Dose Value | (3008,0016) | 1 | Measured Dose in units specified by Dose Units (3004,0002) in sequence referenced by Measured Dose Reference Sequence (3008,0010) or Dose Reference Sequence (300A,0010) in RT Prescription Module of Referenced RT Ion Plan as defined above.
>Referenced Calculated Dose Reference Sequence | (3008,0090) | 3 | Sequence of doses estimated for each treatment delivery. One or more Items are permitted in this sequence.
>>Referenced Dose Reference Number | (300C,0051) | 1C | Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module of referenced RT Ion Plan. Required if Referenced Calculated Dose Reference Number (3008,0092) is not sent.
>>Referenced Calculated Dose Reference Number | (3008,0092) | 1C | Uniquely identifies Calculated Dose Reference specified by Calculated Dose Reference Number (3008,0072) within Calculated Dose Reference Sequence (3008,0070). Required if Referenced Dose Reference Number (300C,0051) is not sent.
>>Calculated Dose Reference Dose Value | (3008,0076) | 1 | Calculated Dose (Gy).
>Number of Wedges | (300A,00D0) | 1 | Number of wedges associated with current beam.
>Recorded Wedge Sequence | (3008,00B0) | 1C | Sequence of treatment wedges. Required if Number of Wedges (300A,00D0) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Wedges (300A,00D0).
>>Wedge Number | (300A,00D2) | 1 | Identification number of the Wedges. The value of Wedge Number (300A,00D2) shall be unique within the Beam in which it was created.
>>Wedge Type | (300A,00D3) | 2 | Type of wedge (if any) defined for Beam. Defined Terms: STANDARD standard (static) wedge MOTORIZED single wedge that can be removed from beam remotely. PARTIAL_STANDARD wedge does not extend across the whole field and is operated manually. PARTIAL_MOTORIZ wedge does not extend across the whole field and can be removed from beam remotely.
>>Wedge ID | (300A,00D4) | 3 | User-supplied identifier for Wedge.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Wedge Angle | (300A,00D5) | 2 | Nominal wedge angle (degrees).
>>Wedge Orientation | (300A,00D8) | 2 | Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to the IEC BEAM LIMITING DEVICE coordinate systems (degrees).
>Number of Compensators | (300A,00E0) | 1 | Number of range compensators associated with current Beam.
>Recorded Compensator Sequence | (3008,00C0) | 1C | Sequence of treatment compensators. Required if Number of Compensators (300A,00E0) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Compensators (300A,00E0).
>>Referenced Compensator Number | (300C,00D0) | 1 | Uniquely identifies compensator specified by Compensator Number (300A,00E4) within Beam referenced by Referenced Beam Number (300C,0006).
>>Compensator ID | (300A,00E5) | 3 | User-supplied identifier for compensator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Number of Boli | (300A,00ED) | 1 | Number of boli associated with current Beam.
>Referenced Bolus Sequence | (300C,00B0) | 1C | Sequence of boli associated with Beam. Required if Number of Boli (300A,00ED) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Boli (300A,00ED).
>>Referenced ROI Number | (3006,0084) | 1 | Uniquely identifies ROI representing the Bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Number of Blocks | (300A,00F0) | 1 | Number of shielding blocks associated with Beam.
>Recorded Block Sequence | (3008,00D0) | 1C | Sequence of blocks associated with Beam. Required if Number of Blocks (300A,00F0) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Blocks (300A,00F0).
>>Block Tray ID | (300A,00F5) | 3 | User-supplied identifier for block tray.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Referenced Block Number | (300C,00E0) | 1 | Uniquely identifies block specified by Block Number (300A,00FC) within Beam referenced by Referenced Beam Number (300C,0006).
>>Block Name | (300A,00FE) | 3 | User-defined name for block.
>Recorded Snout Sequence | (3008,00F0) | 1C | Sequence of Snouts associated with Beam. Required if Snout Sequence (300A,030C) is included in the RT Ion Plan referenced within the Referenced RT Plan Sequence (300C,0002). Only a single item shall be included in this sequence.
>>Snout ID | (300A,030F) | 1 | User or machine supplied identifier for Snout.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Applicator Sequence | (300A,0107) | 1C | Sequence of Applicators associated with Beam. Required if Applicator Sequence (300A,0107) is included in the RT Ion Plan referenced within the Referenced RT Plan Sequence (300C,0002). Only a single item shall be included in this sequence.
>>Applicator ID | (300A,0108) | 1 | User or machine supplied identifier for Applicator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Applicator Type | (300A,0109) | 1 | Type of applicator. Defined Terms: ION_SQUARE square ion applicator ION_RECT rectangular ion applicator ION_CIRC circular ion applicator ION_SHORT short ion applicator ION_OPEN open (dummy) ion applicator INTRAOPERATIVE intraoperative (custom) applicator STEREOTACTIC stereotactic applicator
>>Applicator Description | (300A,010A) | 3 | User-defined description for Applicator.
>General Accessory Sequence | (300A,0420) | 3 | Introduces a Sequence of General Accessories associated with this Beam. One or more items are permitted in this sequence.
>>General Accessory Number | (300A,0424) | 1 | Identification Number of the General Accessory. The value shall be unique within the sequence.
>>General Accessory ID | (300A,0421) | 1 | User or machine supplied identifier for General Accessory.
>>General Accessory Description | (300A,0422) | 3 | User supplied description of General Accessory.
>>General Accessory Type | (300A,0423) | 3 | Specifies the type of accessory. Defined Terms: GRATICULE Accessory tray with a radio-opaque grid IMAGE_DETECTOR Image acquisition device positioned in the beam line RETICLE Accessory tray with radio-transparent markers or grid
>>Accessory Code | (300A,00F9) | 3 | Machine-readable identifier for this accessory
>>Source to General Accessory Distance | (300A,0425) | 3 | Radiation source to general accessory distance (in mm) for current accessory.
>Number of Range Shifters | (300A,0312) | 1 | Number of range shifters associated with current beam.
>Recorded Range Shifter Sequence | (3008,00F2) | 1C | Sequence of range shifters recorded with Beam. Required if Number of Range Shifters (300A,0312) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Range Shifters (300A,0312).
>>Referenced Range Shifter Number | (300C,0100) | 1 | Uniquely identifies range shifter specified by Range Shifter Number (300A,0316) within Beam referenced by Referenced Beam Number (300C,0006).
>>Range Shifter ID | (300A,0318) | 1 | User or machine supplied identifier for Range Modulator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Number of Lateral Spreading Devices | (300A,0330) | 1 | Number of lateral spreading devices associated with current beam.
>Recorded Lateral Spreading Device Sequence | (3008,00F4) | 1C | Sequence of lateral spreading devices associated with Beam. Required if Number of Lateral Spreading Devices (300A,0330) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Lateral Spreading Devices (300A,0330).
>>Referenced Lateral Spreading Device Number | (300C,0102) | 1 | Uniquely identifies lateral spreading device specified by Lateral Spreading Device Number (300A,0334) within Beam referenced by Referenced Beam Number (300C,0006).
>>Lateral Spreading Device ID | (300A,0336) | 1 | User or machine supplied identifier for Lateral Spreading Device.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>Number of Range Modulators | (300A,0340) | 1 | Number of range modulators associated with current beam.
>Recorded Range Modulator Sequence | (3008,00F6) | 1C | Sequence of range modulators associated with Beam. Required if Number of Range Modulators (300A,0340) is non-zero. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Range Modulators (300A,0340).
>>Referenced Range Modulator Number | (300C,0104) | 1 | Uniquely identifies range modulator specified by Range Modulator Number (300A,0344) within Beam referenced by Referenced Beam Number (300C,0006).
>>Range Modulator ID | (300A,0346) | 1 | User or machine supplied identifier for Range Modulator.
>>Accessory Code | (300A,00F9) | 3 | An accessory identifier to be read by a device such as a bar code reader.
>>Range Modulator Type | (300A,0348) | 1 | Type of Range Modulator. Defined Terms: FIXED fixed modulation width and weights using ridge filter or constant speed wheel with constant beam current WHL_FIXEDWEIGHTS selected wheel/track (Range Modulator ID) is spinning at constant speed. Modulation width is adjusted by switching constant beam current on and off at wheel steps indicated by Range Modulator Interrupt Values WHL_MODWEIGHTS selected wheel/track (Range Modulator ID) is spinning at constant speed. Weight per wheel step is adjusted by modulating beam current according to selected Beam Current Modulation ID (300A,034C) Only one item in the Recorded Range Modulator Sequence (3008,00F6) can have a Range Modulator Type (300A,0348) of WHL_MODWEIGHTS.
>>Beam Current Modulation ID | (300A,034C) | 1C | User-supplied identifier for the beam current modulation pattern. Required if Range Modulator Type (300A,0348) is WHL_MODWEIGHTS
>Include Table C.8.8.28-1 “Patient Support Identification Macro Attributes” |
>Fixation Light Azimuthal Angle | (300A,0356) | 3 | Azimuthal angle (degrees) of the fixation light coordinate around IEC PATIENT SUPPORT Y-axis. Used for eye treatments. See Section C.8.8.25.6.4.
>Fixation Light Polar Angle | (300A,0358) | 3 | Polar angle (degrees) of the fixation light coordinate. Used for eye treatments. See Section C.8.8.25.6.4.
>Current Fraction Number | (3008,0022) | 2 | Fraction number for this beam administration.
>Treatment Delivery Type | (300A,00CE) | 2 | Delivery Type of treatment. Defined Terms: TREATMENT normal patient treatment OPEN_PORTFILM portal image acquisition with open field (the source of radiation is specified by Radiation Type (300A,00C6)) TRMT_PORTFILM portal image acquisition with treatment port (the source of radiation is specified by Radiation Type (300A,00C6)) CONTINUATION continuation of interrupted treatment SETUP no treatment beam was applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements were taken VERIFICATION Treatment used for Quality Assurance rather than patient treatment
>Treatment Termination Status | (3008,002A) | 1 | Conditions under which treatment was terminated. Enumerated Values: NORMAL treatment terminated normally OPERATOR operator terminated treatment MACHINE machine terminated treatment UNKNOWN status at termination unknown
>Treatment Termination Code | (3008,002B) | 3 | Treatment machine termination code. This code is dependent upon the particular application and equipment.
>Treatment Verification Status | (3008,002C) | 2 | Conditions under which treatment was verified by a verification system. Enumerated Values: VERIFIED treatment verified VERIFIED_OVR treatment verified with at least one out-of-range value overridden NOT_VERIFIED treatment verified manually
>Specified Primary Meterset | (3008,0032) | 3 | Desired machine setting of primary Meterset in units specified by Primary Dosimeter Unit (300A,00B3). See Section C.8.8.26.1.
>Specified Secondary Meterset | (3008,0033) | 3 | Desired machine setting of secondary Meterset. See Section C.8.8.26.1.
>Delivered Primary Meterset | (3008,0036) | 3 | Machine setting actually delivered as recorded by primary Meterset in units specified by Primary Dosimeter Unit (300A,00B3). See Section C.8.8.26.1.
>Delivered Secondary Meterset | (3008,0037) | 3 | Machine setting actually delivered as recorded by secondary Meterset. See Section C.8.8.26.1.
>Specified Treatment Time | (3008,003A) | 3 | Treatment Time set (sec).
>Delivered Treatment Time | (3008,003B) | 3 | Treatment Time actually delivered (sec).
>Number of Control Points | (300A,0110) | 1 | Number of control points in Beam.
>Ion Control Point Delivery Sequence | (3008,0041) | 1 | Sequence of beam control points for current ion treatment beam. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Control Points (300A,0110). See Section C.8.8.21.1.
>>Referenced Control Point Index | (300C,00F0) | 1 | Uniquely identifies Control Point specified by Control Point Index (300A,0112) within the Beam referenced by Referenced Beam Number (300C,0006).
>>Treatment Control Point Date | (3008,0024) | 1 | Date when the delivery of radiation at this control point began. For the final control point this shall be the Date when the previous control point ended.
>>Treatment Control Point Time | (3008,0025) | 1 | Time when the delivery of radiation at this control point began. For the final control point this shall be the Time when the previous control point ended.
>>Specified Meterset | (3008,0042) | 2 | Desired machine setting for current control point in units specified by Primary Dosimeter Unit (300A,00B3).
>>Delivered Meterset | (3008,0044) | 1 | Machine setting actually delivered at current control point in units specified by Primary Dosimeter Unit (300A,00B3).
>>Meterset Rate Set | (3008,0045) | 3 | The specified speed of delivery of the specified dose in units specified by Primary Dosimeter Unit (300A,00B3) per minute.
>>Meterset Rate Delivered | (3008,0046) | 3 | The delivered speed of delivery of the specified dose in units specified by Primary Dosimeter Unit (300A,00B3) per minute.
>>Nominal Beam Energy | (300A,0114) | 1C | Nominal Beam Energy at control point in MeV per nucleon. Defined at nozzle entrance before all Beam Modifiers. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Nominal Beam Energy (300A,0114) changes during beam administration, and KVP (0018,0060) is not present.
>>KVP | (0018,0060) | 1C | Peak kilo voltage output of the setup X-Ray generator used. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041), or if kVp changes during setup, and Nominal Beam Energy (300A,0114) is not present.
>>Ion Wedge Position Sequence | (300A,03AC) | 1C | Sequence of Wedge positions for current control point. Required for first item of Ion Control Point Sequence if Number of Wedges (300A,00D0) is non-zero, and in subsequent control points if Wedge Position (300A,0118) or Wedge Thin Edge Position (300A,00DB) changes during beam. One or more items shall be included in this sequence. The number of items shall be identical to the value of Number of Wedges (300A,00D0).
>>>Referenced Wedge Number | (300C,00C0) | 1 | Uniquely references Wedge described by Wedge Number (300A,00D2) in Wedge Sequence (300A,00D1).
>>>Wedge Position | (300A,0118) | 1 | Position of Wedge at current control point. Enumerated Values: IN OUT
>>>Wedge Thin Edge Position | (300A,00DB) | 1C | Closest distance from the central axis of the beam along a wedge axis to the thin edge as projected to the machine isocentric plane (mm). Value is positive is the wedge does not cover the central axis, negative if it does. Required if Wedge Type (300A,00D3) of the wedge referenced by Referenced Wedge Number (300C,00C0) is PARTIAL_STANDARD or PARTIAL_MOTORIZ. See Section C.8.8.25.6.4.
>>Include Table C.8.8.27-1 “Beam Limiting Device Position Macro Attributes” |
>>Range Shifter Settings Sequence | (300A,0360) | 1C | Sequence of Range Shifter settings for the current control point. One or more items shall be included in this sequence. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Range Shifter Setting (300A,0362) changes during beam administration,and Number of Range Shifters (300A,0312) is non-zero.
>>>Referenced Range Shifter Number | (300C,0100) | 1 | Uniquely references Range Shifter described by Range Shifter Number (300A,0316) in Range Shifter Sequence (300A,0314).
>>>Range Shifter Setting | (300A,0362) | 1 | Machine specific setting attribute for the range shifter. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.
>>Lateral Spreading Device Settings Sequence | (300A,0370) | 1C | Sequence of Lateral Spreading Device settings for the current control point. One or more items shall be included in this sequence. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Lateral Spreading Device Setting (300A,0372) changes during beam administration, and Number of Lateral Spreading Devices (300A,0330) is non-zero.
>>>Referenced Lateral Spreading Device Number | (300C,0102) | 1 | Uniquely references Lateral Spreading Device described by Lateral Spreading Device Number (300A,0334) in Lateral Spreading Device Sequence (300A,0332).
>>>Lateral Spreading Device Setting | (300A,0372) | 1 | Machine specific setting attribute for the lateral spreading device. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.
>>Range Modulator Settings Sequence | (300A,0380) | 1C | Sequence of Range Modulator Settings for current control point. One or more items shall be included in this sequence. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041), or if Range Modulator Settings change during beam administration, and Number of Range Modulators (300A,0340) is non-zero.
>>>Referenced Range Modulator Number | (300C,0104) | 1 | Uniquely references Range Modulator described by Range Modulator Number (300A,0344) in Range Modulator Sequence (300A,0342).
>>>Range Modulator Gating Start Value | (300A,0382) | 1C | Start position defines the range modulator position at which the beam is switched on. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS
>>>Range Modulator Gating Stop Value | (300A,0384) | 1C | Stop position defines the range modulator position at which the beam is switched off. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS
>>Gantry Angle | (300A,011E) | 1C | Treatment machine gantry angle, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Gantry Angle changes during beam administration.
>>Gantry Rotation Direction | (300A,011F) | 1C | Direction of Gantry Rotation when viewing gantry from isocenter, for segment beginning at current Control Point. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041), or if Gantry Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Gantry Pitch Angle | (300A,014A) | 2C | Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Angle changes during Beam. See Section C.8.8.25.6.5.
>>Gantry Pitch Rotation Direction | (300A,014C) | 2C | Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.5. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Beam Limiting Device Angle | (300A,0120) | 1C | Beam Limiting Device (collimator) angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if beam limiting device (collimator) angle changes during beam administration.
>>Beam Limiting Device Rotation Direction | (300A,0121) | 1C | Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment beginning at current Control Point. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Beam Limiting Device Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Scan Spot Tune ID | (300A,0390) | 1C | User-supplied or machine code identifier for machine configuration to produce beam spot. This may be the nominal spot size or some other machine specific value. Required if Scan Mode (300A,0308) is MODULATED.
>>Number of Scan Spot Positions | (300A,0392) | 1C | Number of spot positions used to specify scanning pattern for current segment beginning at control point. Required if Scan Mode (300A,0308) is MODULATED.
>>Scan Spot Position Map | (300A,0394) | 1C | The x and y coordinates of the scan spots are defined as projected onto the machine isocentric plane in the IEC GANTRY coordinate system (mm). Required if Scan Mode (300A,0308) is MODULATED. Contains 2N values were N is the Number of Scan Spot Positions (300A,0392).
>>Scan Spot Metersets Delivered | (3008,0047) | 1C | A data set of Metersets delivered to the scan spot positions. The order of Metersets matches the positions in Scan Spot Position Map (300A,0394). The sum contained in all Metersets shall match the difference of the Delivered Meterset of the current control point to the following control point. Required if Scan Mode (300A,0308) is MODULATED.
>>Scanning Spot Size | (300A,0398) | 3 | The Scanning Spot Size as calculated using the Full Width Half Maximum (FWHM). Specified by a numeric pair - the size measured in air at isocenter in IEC GANTRY X direction followed by the size in the IEC GANTRY Y direction (mm).
>>Number of Paintings | (300A,039A) | 1C | The intended number of times the scan pattern given by Scan Spot Position Map (300A,0394) and Scan Spot Meterset Weights (300A,0396) in the Referenced RT Plan was to be applied at the current control point. ### Note The actual number of paintings is not known or recorded. The Scan Spot Metersets Delivered (3008,0047) contains the sum of all complete and partial repaints. Required if Scan Mode (300A,0308) is MODULATED.
>>Patient Support Angle | (300A,0122) | 1C | Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Patient Support Angle changes during beam administration.
>>Patient Support Rotation Direction | (300A,0123) | 1C | Direction of Patient Support Rotation when viewing table from above, for segment beginning at current Control Point. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041), or if Patient Support Rotation Direction changes during beam administration. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Pitch Angle | (300A,0140) | 2C | Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Pitch Angle changes during Beam. See Section C.8.8.25.6.2.
>>Table Top Pitch Rotation Direction | (300A,0142) | 2C | Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Table Top Roll Angle | (300A,0144) | 2C | Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Roll Angle changes during Beam. See Section C.8.8.25.6.2.
>>Table Top Roll Rotation Direction | (300A,0146) | 2C | Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Roll Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2. Enumerated Values: CW clockwise CC counter-clockwise NONE no rotation
>>Head Fixation Angle | (300A,0148) | 3 | Angle (in degrees) of the head fixation for eye treatments with respect to the Table Top Pitch Angle (300A,0140) coordinate system. Positive head fixation angle is the same direction as positive Table Top Pitch. See Section C.8.8.25.6.4.
>>Table Top Vertical Position | (300A,0128) | 2C | Table Top Vertical position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Table Top Vertical Position changes during beam administration.
>>Table Top Longitudinal Position | (300A,0129) | 2C | Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Table Top Longitudinal Position changes during beam administration.
>>Table Top Lateral Position | (300A,012A) | 2C | Table Top Lateral position in IEC TABLE TOP coordinate system (mm). This value is interpreted as an absolute, rather than relative, Table setting. Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Table Top Lateral Position changes during beam administration.
>>Snout Position | (300A,030D) | 2C | Axial position of the snout (in mm) measured from isocenter to the downstream side of the snout (without consideration of variable length elements such as blocks, MLC and/or compensators). Required for Control Point 0 of Ion Control Point Delivery Sequence (3008,0041) or if Snout Position changes during beam administration.
>>Corrected Parameter Sequence | (3008,0068) | 3 | Introduces a sequence of items describing corrections made to any attributes prior to delivery of the next control point. One or more Items are permitted in this sequence.
>>>Parameter Sequence Pointer | (3008,0061) | 1 | Contains the Data Element Tag of the parent sequence containing the attribute that was corrected. The value is limited in scope to the Treatment Session Ion Beam Sequence (3008,0021) and all nested sequences therein.
>>>Parameter Item Index | (3008,0063) | 1 | Contains the ones-based sequence item index of the corrected attribute within its parent sequence as indicated by Parameter Sequence Pointer (3008,0061).
>>>Parameter Pointer | (3008,0065) | 1 | Contains the Data Element Tag of the attribute that was corrected.
>>>Correction Value | (3008,006A) | 1 | The value that was added the value referenced by the Parameter Sequence Pointer (3008,0061), Parameter Item Index (3008,0063) and Parameter Pointer (3008,0065).
>>Override Sequence | (3008,0060) | 3 | Sequence of parameters that were overridden during the administration of the beam segment immediately prior to the current control point. One or more Items are permitted in this sequence.
>>>Parameter Sequence Pointer | (3008,0061) | 1 | Contains the Data Element Tag of the parent sequence containing the attribute that was overriden. The value is limited in scope to the Treatment Session Ion Beam Sequence (3008,0021) and all nested sequences therein.
>>>Override Parameter Pointer | (3008,0062) | 1 | Contains the Data Element Tag of the attribute that was overridden.
>>>Parameter Item Index | (3008,0063) | 1 | Contains the ones-based sequence item index of the overriden attributes within it's parent sequence. The value is limited in scope to the Treatment Session Ion Beam Sequence (3008,0021) and all nested sequences therein.
>>>Operators' Name | (0008,1070) | 2 | Name of operator who authorized override.
>>>Override Reason | (3008,0066) | 3 | User-defined description of reason for override of parameter specified by Override Parameter Pointer (3008,0062).

##### C.8.8.26.1 Specified and Delivered Meterset Values

Specified and Delivered Meterset values on beam and control point level shall be handled as specified for RT Beams Session records in Section C.8.8.21.2.

#### C.8.8.27 Beam Limiting Device Position Macro

Table C.8.8.27-1 specifies the attributes that specify the Beam Limiting Device Sequence.

Table C.8.8.27-1. Beam Limiting Device Position Macro Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Beam Limiting Device Position Sequence | (300A,011A) | 1C | Sequence of beam limiting device (collimator) jaw or leaf (element) positions. One or more items shall be included in this sequence. Required if Ion Beam Limiting Device Sequence (300A,03A4) or Beam Limiting Device Leaf Pairs Sequence (3008,00A0) is included in this SOP instance and for first item of Ion Control Point Sequence, or if Beam Limiting Device changes during Beam.
>RT Beam Limiting Device Type | (300A,00B8) | 1 | Type of beam limiting device (collimator). The value of this attribute shall correspond to RT Beam Limiting Device Type (300A,00B8) defined in an item of Ion Beam Limiting Device Sequence (300A,03A4). Enumerated Values: X symmetric jaw pair in IEC X direction Y symmetric jaw pair in IEC Y direction ASYMX asymmetric jaw pair in IEC X direction ASYMY asymmetric pair in IEC Y direction MLCX multileaf (multi-element) jaw pair in IEC X direction MLCY multileaf (multi-element) jaw pair in IEC Y direction
>Leaf/Jaw Positions | (300A,011C) | 1 | Positions of beam limiting device (collimator) leaf (element) or jaw pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g., X-axis for MLCX, Y-axis for MLCY. Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC) in Ion Beam Limiting Device Sequence (300A,03A4). Values shall be listed in IEC leaf (element) subscript order 101, 102, … 1N, 201, 202, … 2N. See Section C.8.8.25.3.

#### C.8.8.28 Patient Support Identification Macro

Table C.8.8.28-1 specifies the attributes that identify the Patient Support System.

Table C.8.8.28-1. Patient Support Identification Macro Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Patient Support Type | (300A,0350) | 1 | Defined Terms: TABLE Treatment delivery system table CHAIR Treatment delivery system chair See Section C.8.8.25.6.3.
Patient Support ID | (300A,0352) | 3 | User-specified identifier for manufacturer specific patient support devices.
Patient Support Accessory Code | (300A,0354) | 3 | A Patient Support accessory identifier to be read by a device such as a bar code reader.

#### C.8.8.29 RT Beams Delivery Instruction Module

The RT Beams Delivery Instruction Module contains additional information required by a Treatment Delivery System (TDS) when specifying delivery of an external beam radiotherapy treatment. This information is supplied by a Treatment Management System (TMS) when it creates an RT Beams Delivery Instruction SOP Instance, a composite SOP Instance in turn referenced by a Unified Procedure Step (UPS) in the Unified Procedure Step model.

The RT Beams Delivery Instruction Module consists of a sequence of one or more beam tasks, where each beam task may also specify one or more Delivery Verification images to be acquired prior to, during, or after the treatment delivery.

Table C.8.8.29-1. RT Beams Delivery Instruction Module Attributes

Attribute Name | Tag | Type | Description
--- | --- | --- | ---
Referenced RT Plan Sequence | (300C,0002) | 1 | Reference to a single RT Plan or RT Ion Plan SOP Instance (whose UID is also supplied in the Input Information Sequence - see PS3.4) containing all the Beams and the Fraction Group referenced in this SOP Instance. Only a single item shall be included in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Beam Task Sequence | (0074,1020) | 1 | Specification of beams to be delivered and/or verified. One or more Items shall be included in this sequence.
>Beam Task Type | (0074,1022) | 1 | Indication whether beam is to be verified, treated (delivered), or both. Enumerated Values: VERIFY Beam verification only TREAT Beam treatment only VERIFY_AND_TREAT Beam verification and treatment
>Treatment Delivery Type | (300A,00CE) | 1 | Delivery Type of treatment. Enumerated Values: TREATMENT normal patient treatment CONTINUATION continuation of interrupted treatment
>Primary Dosimeter Unit | (300A,00B3) | 1C | Measurement unit of machine dosimeter. Enumerated Values: MU Monitor Unit MINUTE minute NP Number of Particles This value shall be the same as in the referenced RT Plan. It applies only to the Continuation Start Meterset (0074,0120) and Continuation End Meterset (0074,0121). Required if Treatment Delivery Type (300A,00CE) is CONTINUATION.
>Continuation Start Meterset | (0074,0120) | 1C | Meterset within Beam referenced by Referenced Beam Number (300C,0006) at which treatment delivery starts, in units specified by Primary Dosimeter Unit (300A,00B3). Required if Treatment Delivery Type (300A,00CE) is CONTINUATION.
>Continuation End Meterset | (0074,0121) | 1C | Meterset within Beam referenced by Referenced Beam Number (300C,0006) at which treatment delivery ends, in units specified by Primary Dosimeter Unit (300A,00B3). Required if Treatment Delivery Type (300A,00CE) is CONTINUATION.
>Current Fraction Number | (3008,0022) | 1 | The index of the fraction that is to be delivered or completed in this session. See Section C.8.8.29.1.
>Referenced Fraction Group Number | (300C,0022) | 1C | Indicates which fraction group of the referenced plan is to be treated in the treatment session. Only one Fraction Group shall be specified per Delivery Instruction SOP Instance. Required if the referenced plan has more than one Fraction Group Sequence (300A,0070) item.
>Referenced Beam Number | (300C,0006) | 1 | Uniquely identifies the Beam that is specified by Beam Number (300A,00C0) within Beam Sequence (300A,00B0) in RT Beams Module of referenced RT Plan or RT Ion Plan.
>Beam Order Index | (0074,1324) | 3 | Identifies required ordering of beam delivery, monotonically increasing by 1, starting from 1. See Section C.8.8.29.5.
>Autosequence Flag | (0074,1025) | 3 | Enumerated Values: YES The current beam shall be automatically treated following the preceding beam as defined by the Beam Order Index (0074,1324). NO The current beam shall not be auto-sequenced. See Section C.8.8.29.6.
>Table Top Vertical Adjusted Position | (0074,1026) | 2 | Adjusted Table Top Vertical position in the IEC TABLE TOP coordinate system in mm for patient setup. See Section C.8.8.29.2.
>Table Top Longitudinal Adjusted Position | (0074,1027) | 2 | Adjusted Table Top Longitudinal position in the IEC TABLE TOP coordinate system in mm for patient setup. See Section C.8.8.29.2.
>Table Top Lateral Adjusted Position | (0074,1028) | 2 | Adjusted Table Top Lateral position in the IEC TABLE TOP coordinate system in mm for patient setup. See Section C.8.8.29.2.
>Patient Support Adjusted Angle | (0074,102A) | 2 | Adjusted Patient Support angle for patient setup, i.e., orientation of the IEC PATIENT SUPPORT coordinate system with respect to the IEC FIXED REFERENCE coordinate system in degrees. See Section C.8.8.29.2.
>Table Top Eccentric Adjusted Angle | (0074,102B) | 2 | Adjusted Table Top (non-isocentric) angle for patient setup, i.e., orientation of the IEC TABLE TOP ECCENTRIC coordinate system with respect to the IEC PATIENT SUPPORT system in degrees. See Section C.8.8.29.2.
>Table Top Pitch Adjusted Angle | (0074,102C) | 2 | Adjusted Table Top Pitch Angle for patient setup, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system in degrees. See Section C.8.8.29.2.
>Table Top Roll Adjusted Angle | (0074,102D) | 2 | Adjusted Table Top Roll Angle for patient setup, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system in degrees. See Section C.8.8.29.2.
>Table Top Vertical Setup Displacement | (300A,01D2) | 2 | Vertical Displacement in the IEC TABLE TOP coordinate system in mm relative to initial Setup Position, i.e., vertical offset between patient positioning performed using setup and treatment position.
>Table Top Longitudinal Setup Displacement | (300A,01D4) | 2 | Longitudinal Displacement in the IEC TABLE TOP coordinate system in mm relative to initial Setup Position, i.e., longitudinal offset between patient positioning performed using setup and treatment position.
>Table Top Lateral Setup Displacement | (300A,01D6) | 2 | Lateral Displacement in the IEC TABLE TOP coordinate system in mm relative to initial Setup Position, i.e., lateral offset between patient positioning performed using setup and treatment position.
>Delivery Verification Image Sequence | (0074,1030) | 2C | Beam verification images to be acquired for current beam. Required if Beam Task Type (0074,1022) is VERIFY or VERIFY_AND_TREAT. Zero or one Item shall be included in this sequence if Beam Task Type (0074,1022) is VERIFY. Zero or more Items shall be included in this sequence if Beam Task Type (0074,1022) is VERIFY_AND_TREAT.
>>Verification Image Timing | (0074,1032) | 1 | Indicates the temporal relationship of the verification image with respect to the current treatment beam delivery. Value shall be DURING_BEAM for Beams with a Beam Task Type (0074,1022) of VERIFY. Enumerated Values: BEFORE_BEAM DURING_BEAM AFTER_BEAM
>>Start Cumulative Meterset Weight | (300C,0008) | 1C | Cumulative Meterset Weight within current Beam at which image acquisition will start. Required if Verification Image Timing (0074,1032) is DURING_BEAM.
>>Meterset Exposure | (3002,0032) | 2C | Treatment machine Meterset duration over which image is to be acquired, specified in Monitor units (MU) or minutes as defined by Primary Dosimeter Unit (300A,00B3) specified in the Referenced RT Plan Sequence (300C,0002). Required if Verification Image Timing (0074,1032) is BEFORE_BEAM or AFTER_BEAM. See Section C.8.8.29.3.
>>End Cumulative Meterset Weight | (300C,0009) | 2C | Cumulative Meterset Weight within current Beam at which image acquisition will end. Required if Verification Image Timing (0074,1032) is DURING_BEAM.
>>Double Exposure Flag | (0074,1034) | 1 | Indicates whether the current verification image is a single or double exposure. Enumerated Values: SINGLE single exposure DOUBLE double exposure
>>Double Exposure Ordering | (0074,1036) | 1C | Indicates the ordering of the open (double exposure) field with respect to the primary (collimated) field in a double exposure. Defined Terms: OPEN_FIRST Open field first OPEN_SECOND Open field second Required if Double Exposure Flag (0074,1034) is DOUBLE.
>>Double Exposure Meterset | (0074,1338) | 2C | If this field is present, an additional exposure with the indicated Meterset is requested. Required if Double Exposure Flag (0074,1034) is DOUBLE.
>>Double Exposure Field Delta | (0074,133A) | 2C | Offsets of field-defining edges in mm for the double exposure in the IEC BEAM LIMITING DEVICE coordinate system in the IEC order X1, X2, Y1, Y2. Negative values for X1 and Y1 indicate an enlarged field, negative values for X2 and Y2 indicate a reduced field. Required if Double Exposure Flag (0074,1034) is DOUBLE. See Section C.8.8.29.4.
>>X-Ray Image Receptor Translation | (3002,000D) | 2 | Position in (x,y,z) coordinates in mm of origin of the IEC X-RAY IMAGE RECEPTOR System in the IEC GANTRY coordinate system.
>>Related Reference RT Image Sequence | (0074,1040) | 3 | Uniquely identifies Reference Images to which planned verification image is related. All items in this sequence shall be RT Image SOP Instances. One or more items are permitted in this sequence.
>>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

##### C.8.8.29.1 Current Fraction Number

For beams with a Treatment Delivery Type (300A,00CE) of CONTINUATION, the Current Fraction Number (3008,0022) is that of the original fraction to be completed by the current beam.

##### C.8.8.29.2 Adjusted Table Positions and Angles

Adjusted Table positions and angles serve as a facility to communicate a shift (often systematic) that has been detected from previous treatments. They define a new initial patient position, which is near and aligned to the actual patient position during beam delivery. These attributes do not affect the original relationship between the beams and the planning image patient anatomy.

##### C.8.8.29.3 Meterset Exposure

Meterset Exposure (3002,0032) can be interpreted as the 'maximum' Meterset duration in cases where an automatic exposure is taken.

##### C.8.8.29.4 Double Exposure Field Delta

The following diagram illustrates the case where the second X aperture in a double exposure is larger than the initial aperture. In this case ΔX1 is negative and ΔX2 is positive. If a field edge is defined by a multileaf collimator, then the field delta is to be applied to the most open leaf, such that all leaves can be moved to that position.

Figure C.8.8.29-1. Double Exposure Field Delta

##### C.8.8.29.5 Beam Order Index

If the Beam Order Index (0074,1324) is present for any item in the Beam Task Sequence (0074,1020), it shall be provided for all items in that sequence.

##### C.8.8.29.6 Autosequence Flag

Autosequence Flag (0074,1025) shall not be present when the Beam Order Index (0074,1324) is not present. The first treatment Beam (Beam Task Type (0074,1022) is not VERIFY) as specified by the Beam Order Index (0074,1324), shall have an Autosequence Flag (0074,1025) value of NO.

### C.8.9 PET Information Module Definitions

This Section describes Positron Emission Tomography series and image Modules. These Modules contain Attributes that are specific to Positron Emission Tomography images.

#### C.8.9.1 PET Series Module

Table C.8-60 contains IOD Attributes that describe a PET Series.

Table C.8-60. PET Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Series Date | (0008,0021) | 1 | Date the Series started. See Section C.8.9.1.1.2 for specialization.
Series Time | (0008,0031) | 1 | Time the Series started. See Section C.8.9.1.1.2 for specialization.
Units | (0054,1001) | 1 | Pixel value units. See Section C.8.9.1.1.3 for explanation. Defined Terms: CNTS NONE CM2 CM2ML PCNT CPS BQML MGMINML UMOLMINML MLMING MLG 1CM UMOLML PROPCNTS PROPCPS MLMINML MLML GML STDDEV
SUV Type | (0054,1006) | 3 | Type of Standardized Uptake Value (SUV). Enumerated Values: BSA body surface area BW body weight LBM lean body mass IBW - ideal body weight If absent, and the Units (0054,1001) are GML, then the type of SUV shall be assumed to be BW. ### Note The type of SUV cannot reliably be deduced from the units alone, i.e., SUVbw, SUVibw and SUVlbm all have units of GML.
Counts Source | (0054,1002) | 1 | The primary source of counts. The primary source leads to the underlying image Units (0054,1001), as opposed to secondary sources that are used during reconstruction correction. Enumerated Values: EMISSION TRANSMISSION
Series Type | (0054,1000) | 1 | A multi-valued indicator of the type of Series. See Section C.8.9.1.1.4 for explanation. Value 1 Enumerated Values: STATIC DYNAMIC GATED WHOLE BODY Value 2 Enumerated Values: IMAGE REPROJECTION
Reprojection Method | (0054,1004) | 2C | Method for projecting volumetric data onto planar projection. Required if Series Type (0054,1000), Value 2 is REPROJECTION. Defined Terms: SUM MAX PIXEL
Number of R-R Intervals | (0054,0061) | 1C | The maximum number of R-R Intervals that may exist in this Series. Required if Series Type (0054,1000), Value 1 is GATED.
Number of Time Slots | (0054,0071) | 1C | The maximum number of Time Slots that may exist in this Series. Required if Series Type (0054,1000), Value 1 is GATED.
Number of Time Slices | (0054,0101) | 1C | The maximum number of Time Slices that may exist in this Series. Required if Series Type (0054,1000), Value 1 is DYNAMIC.
Number of Slices | (0054,0081) | 1 | The maximum number of Slices that may exist in this Series.
Corrected Image | (0028,0051) | 2 | One or more values that indicate which, if any, corrections have been applied to the images in this series. Defined Terms: DECY decay corrected ATTN attenuation corrected SCAT scatter corrected DTIM dead time corrected MOTN gantry motion corrected (e.g., wobble, clamshell) PMOT patient motion corrected CLN count loss normalization (correction for count loss in gated Time Slots) RAN randoms corrected RADL non-uniform radial sampling corrected DCAL sensitivity calibrated using dose calibrator NORM detector normalization
Randoms Correction Method | (0054,1100) | 3 | Type of randoms correction processing. Defined Terms: NONE no randoms correction DLYD delayed event subtraction SING singles estimation
Attenuation Correction Method | (0054,1101) | 3 | A textual description of the attenuation correction processing. e.g., measured vs. calculated, transmission source type (ring, line, point), assumed patient geometry (polygon, ellipse, segmented, attenuation coefficient, skull thickness), post-injection transmission, smoothing.
Scatter Correction Method | (0054,1105) | 3 | A textual description of the scatter correction processing. e.g., convolution-subtraction, dual energy window, model-based, use of attenuation data.
Decay Correction | (0054,1102) | 1 | The real-world event to which images in this Series were decay corrected. See Section C.8.9.1.1.5 for explanation. Defined Terms: NONE no decay correction START acquisition start time ADMIN radiopharmaceutical administration time
Reconstruction Diameter | (0018,1100) | 3 | Diameter, in mm, of the region within which the data was used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region.
Convolution Kernel | (0018,1210) | 3 | Textual description of the convolution kernel(s) used to reconstruct the data (e.g., name, cutoff, radial/axial/angular, mathematical form, DC handling)
Reconstruction Method | (0054,1103) | 3 | Textual description of reconstruction processing, e.g., 2D filtered backprojection, 2D iterative, 3D PROMIS, 3D FAVOR, 3D iterative.
Detector Lines of Response Used | (0054,1104) | 3 | Textual description of which detector lines of response were used, mashed, or otherwise processed during tomographic reconstruction.
Acquisition Start Condition | (0018,0073) | 3 | Description of how the data collection was started. Defined Terms: DENS density (counts/sec) RDD relative density difference (change in counts/sec) MANU manual TIME time AUTO automatic, when ready TRIG physiological trigger See Section C.8.9.1.1.6 for explanation.
Acquisition Start Condition Data | (0018,0074) | 3 | Count density, change in count density, or physiological triggers causing data collection to start.
Acquisition Termination Condition | (0018,0071) | 3 | Description of how the data collection for the series was stopped. Defined Terms: CNTS counts DENS density (counts/sec) RDD relative density difference (change in counts/sec) MANU manual OVFL data overflow TIME time TRIG physiological trigger See Section C.8.4.9.1.3 for explanation.
Acquisition Termination Condition Data | (0018,0075) | 3 | Number of counts, count density, change in count density, or physiological triggers causing the termination.
Field of View Shape | (0018,1147) | 3 | Shape of the field of view of the PET camera. Defined Terms: CYLINDRICAL RING HEXAGONAL MULTIPLE PLANAR
Field of View Dimensions | (0018,1149) | 3 | Dimensions of the field of view, in mm. Transverse detector diameter followed by axial width.
Gantry/Detector Tilt | (0018,1120) | 3 | Angle of tilt in degrees of the gantry. See Section C.8.9.1.1.7 for explanation.
Gantry/Detector Slew | (0018,1121) | 3 | Angle of slew in degrees of the gantry. Positive slew is moving the gantry on the patient's left toward the patient's superior, when the patient is supine.
Type of Detector Motion | (0054,0202) | 3 | Describes the detector motion during acquisition. Defined Terms: NONE stationary gantry STEP AND SHOOT Interrupted motion, acquire only while stationary CONTINUOUS Gantry motion and acquisition are simultaneous and continuous WOBBLE wobble motion CLAMSHELL clamshell motion
Collimator Type | (0018,1181) | 2 | Collimator Type. Defined Terms: NONE no collimator RING transverse septa
Collimator/Grid Name | (0018,1180) | 3 | Label describing the collimator used.
Axial Acceptance | (0054,1200) | 3 | Maximum axial angle accepted, in degrees.
Axial Mash | (0054,1201) | 3 | Number of adjacent axial lines of response mashed together. See Section C.8.9.1.1.8 for explanation.
Transverse Mash | (0054,1202) | 3 | Number of adjacent transverse lines of response mashed together. See Section C.8.9.1.1.9 for explanation.
Detector Element Size | (0054,1203) | 3 | Size of an individual detector element, in mm. Transverse dimension followed by axial dimension. For a discrete crystal, this is the crystal size. For a continuous detector, this is the pixel bin size.
Coincidence Window Width | (0054,1210) | 3 | The width of the coincidence timing window, in nsec. The maximum time difference accepted between two single events.
Energy Window Range Sequence | (0054,0013) | 3 | Sequence of Items that describes the energy windows used for this Series. One or more Items are permitted in this sequence. See Section C.8.9.1.1.10 for explanation.
>Energy Window Lower Limit | (0054,0014) | 3 | The lower limit of the energy window, in KeV.
>Energy Window Upper Limit | (0054,0015) | 3 | The upper limit of the energy window, in KeV.
Secondary Counts Type | (0054,1220) | 3 | Array defining the type of additional counts accumulated during acquisition. Defined Terms: DLYD delayed events SCAT scattered events in secondary window SING singles DTIM events lost due to deadtime
Scan Progression Direction | (0054,0501) | 3 | The anatomical order in which the slices were acquired. Enumerated Values: FEET_TO_HEAD Slices closest to the patient's feet were acquired first. HEAD_TO_FEET Slices closest to the patient's head were acquired first.

### Note

The formulas for the determination of SUVbw, SUVbsa, SUVlbm and SUVibw are defined in Sugawara et al. Reevaluation of the Standardized Uptake Value for FDG: Variations with Body Weight and Methods for Correction. Radiology, 1999 at http://radiology.rsna.org/content/213/2/521. See also CID 84 “PET Units for Real World Value Mapping” in PS3.16 .

##### C.8.9.1.1 PET Series Attribute Descriptions

### Note

The meaning of a General Series in DICOM is determined by the attributes in the General Series Module and by the Source Entities (Patient, Study, Frame of Reference, Equipment) that originate the Series. The Source Entities are the single-valued entities of the 1->n relationship, where the Series is the multi-valued entity. Therefore, a Series is a group of images that: are from the same patient and study; are from the same Equipment; and, are from the same spatial Frame of Reference.

The PET Image IOD further refines a PET Series IE by the attributes in the PET Series Module, the PET Isotope Module, the PET Multi-gated Acquisition Module and the Acquisition Context Module. These are the attributes that shall not change from Image to Image. Therefore, in addition to the criteria above for a General Series (same patient, study, frame of reference, equipment), the attributes in the PET Series IE define a PET series as a group of images that: are from the same temporal frame of reference; have the same fundamental meaning (e.g., same units: either activity density, metabolism, or attenuation); are derived from the same activity source (emission or transmission); are from the same isotope and radiopharmaceutical; were derived from the same reconstruction processing; and, originated from the same acquisition setup and parameters, including the patient conditions (cardiac stress or rest) if applicable.

###### C.8.9.1.1.1 Specialization of Image Plane Module and Image Pixel Module Attributes

For PET Series, the following Image Pixel Module attributes shall not vary from Image to Image:

- Photometric Interpretation (0028,0004)

- Rows (0028,0010)

- Columns (0028,0011)

- Bits Allocated (0028,0100)

- Bits Stored (0028,0101)

- Pixel Representation (0028,0103)

For PET Series, the following Image Plane Module attributes shall not vary from Image to Image:

- Pixel Spacing (0028,0030)

For PET Series where Series Type (0054,1000), Value 2 is IMAGE, the following Image Plane Module attributes shall not vary from Image to Image:

- Image Orientation (Patient) (0020,0037)

### Note

This means that for a Series Type (0054,1000) Value 2 of IMAGE, all images in the PET Series lie on parallel planes. The images, however, may have non-uniform spacing along the normals to the planes.

For PET Series where Series Type (0054,1000), Value 2 is REPROJECTION, Image Orientation (0020,0037) shall vary such that the images rotate about a single axis. Geometrically, the normal to each image plane is defined by the cross product of its row and column vectors. Each reprojection image has one Center Normal that passes through the center of the image. Reprojection images within a PET Series shall have their Center Normals be co-planar and pass through a single point.

###### C.8.9.1.1.2 Series Date, Series Time

For PET Series, Series Date (0008,0021) and Series Time (0008,0031) are specified to be Type 1. Series Date (0008,0021) and Series Time (0008,0031) are used as the reference time for all PET Image attributes that are temporally related, including activity measurements. Series Date (0008,0021) and Series Time (0008,0031) are not tied to any real-world event (e.g., acquisition start, radiopharmaceutical administration) and their real-world meaning are implementation dependent.

###### C.8.9.1.1.3 Units

The units of the pixel values obtained after conversion from the stored pixel values (SV) (Pixel Data (7FE0,0010)) to pixel value units (U), as defined by Rescale Intercept (0028,1052) and Rescale Slope (0028,1053).

Defined Terms:

CNTS

  counts

NONE

  unitless

CM2

  centimeter**2

PCNT

  percent

CPS

  counts/second

BQML

  Becquerels/milliliter

MGMINML

  milligram/minute/milliliter

UMOLMINML

  micromole/minute/milliliter

MLMING

  milliliter/minute/gram

MLG

  milliliter/gram

1CM

  1/centimeter

UMOLML

  micromole/milliliter

PROPCNTS

  proportional to counts

PROPCPS

  proportional to counts/sec

MLMINM

  milliliter/minute/milliliter

MLML

  milliliter/milliliter

GML

  grams/milliliter

STDDEV

  standard deviations

###### C.8.9.1.1.4 Series Type

Series Type (0054,1000) Value 1 is used to identify the spatial location and temporal nature of the images within a PET Series.

Enumerated Values for Value 1:

STATIC

  a group of images at varying spatial locations at the same time

DYNAMIC

  a group of images at a set of spatial locations (e.g., slices) at varying time slices, with all spatial locations acquired at all time slices

GATED

  a group of images at the same spatial location, same starting and ending time, but acquired in different time slots of (possibly) different R-R intervals

WHOLE BODY

  same as STATIC, except covering multiple transverse fields of view (and therefore acquired at a different time)

### Note

1. Using this definition and the comments in Section C.8.9.1.1.1, here are some examples of PET series and the encoding of Series Type (0054,1000) Value 1.

   - Static acquisition: a group of n transverse images at varying superior<->inferior locations, all acquired between the same starting and ending time. Series Type = STATIC.

   - Dynamic acquisition: a group of n*m transverse images at n superior<->inferior locations, acquired with m different starting and ending times. Series Type = DYNAMIC.

   - Gated acquisition: a group of n*m*p transverse images at n superior<->inferior locations, all acquired between the same starting and ending time, acquired in m different R-R Intervals (as determined by Low R-R Value (0018,1081) and High R-R Value (0018,1082)),and acquired in p time slots of a given R-R Interval (as determined by Trigger Time (0054,1000)). Series Type = GATED.

   - Whole body acquisition: a group of n transverse images at varying superior<->inferior locations covering a significant fraction of the entire body. Series Type = WHOLE BODY.

   - Multiple transverse fields of view: a group of n transverse images at varying superior<->inferior locations. Series Type = WHOLE BODY.

   - Interleaved: group of 2*n transverse images acquired at overlapped AFOVs to increase transverse sampling. Series Type = WHOLE BODY.

   - Sagittal (Coronal, Oblique): sagittal (coronal, oblique) re-sliced images derived by reformatting transverse images. The Series Type is STATIC, DYNAMIC, GATED, or WHOLE BODY depending on source Series Type.

   - Arithmetic: images derived by an arithmetic operation on operand images. The Series Type is STATIC, DYNAMIC, GATED, or WHOLE BODY depending on source Series Type.

   - Metabolic: images derived by a metabolic model. The Series Type is STATIC, DYNAMIC, GATED, or WHOLE BODY depending on source Series Type.

2. Using this definition, here are some images that are not stored in the same PET Series:

   - Two images from the same scan that were reconstructed differently.

   - Emission and transmission images for the same Patient and Study, even if acquired simultaneously (because emission and transmission images have different reconstruction processing).

   - Two images of same patient, one after NH3 injection and one after FDG injection.

   - Two images: an original image created from reconstructed scan data and its derived image based on a metabolic model.

Series Type (0054,1000) Value 2 is used to identify the volumetric meaning of the images within a PET Series.

Enumerated Values for Value 2:

IMAGE

  a tomographic image slice

REPROJECTION

  a projection image derived from forward projection through slices of tomographic images, using the algorithm defined in Reprojection Method (0054,1004)

###### C.8.9.1.1.5 Decay Correction

Decay Correction (0054,1102) is the real-world event to which images in this Series were decay corrected. If decay correction is applied, all images in the Series shall be decay corrected to the same time.

Defined Terms:

NONE

  no decay correction

START

  acquisition start time, Acquisition Time (0008,0032)

ADMIN

  radiopharmaceutical administration time, Radiopharmaceutical Start Time (0018,1072)

The time to which images have been decay corrected can be derived from Decay Factor (0054,1321), Frame Reference Time (0054,1300), Radionuclide Half Life (0018,1075), Series Date (0008,0021) and Series Time (0008,0031).

###### C.8.9.1.1.6 Acquisition Start Condition

Acquisition Start Condition (0018,0073) is the method of starting acquisition data collection.

Defined Terms:

DENS

  preset count density (counts/sec) was reached

RDD

  preset relative count density difference (change in counts/sec) was reached

MANU

  acquisition was started manually

TIME

  preset time limit was reached

AUTO

  start automatically, when ready

TRIG

  preset number of physiological triggers was reached

###### C.8.9.1.1.7 Gantry/Detector Tilt

Gantry/Detector Tilt (0018,1120) for PET Image data is the angle in degrees of the gantry relative to the patient's major (Head to Feet) axis (or the table supporting the patient). Positive tilt is moving the top of the gantry towards the patient's feet.

###### C.8.9.1.1.8 Axial Mash

Axial Mash (0054,1201) is multi-valued and is defined as the number of unique axial Lines of Response (LOR) that were mashed together (center of the axial field of view only). Value 1 is the number of LORs mashed for an odd slice. Value 2 is the number of LORs mashed for an even slice. For discrete crystal scanners, each unique LOR corresponds to a pair of crystals. For continuous detectors whose bin size is variable, the number of LORs mashed is determined by the actual bin size divided by the Detector Element Size (0054,1203), Value 2. The value of Axial Mash (0054,1201) is the same regardless of whether the mashing was done during acquisition or reconstruction.

### Note

As an example on a discrete crystal scanner, if a ring difference of -2,0,+2 are binned as an odd slice and a ring difference of -1,+1 are binned as an even slice, then Axial Mash (0054,1201) is equal to 3\2.

###### C.8.9.1.1.9 Transverse Mash

Transverse Mash (0054,1202) is defined as the number of unique transverse Lines of Response (LOR) that were mashed together. For discrete crystal scanners, each unique LOR corresponds to a pair of crystals. For continuous detectors whose bin size is variable, the number of LORs mashed is determined by the actual bin size divided by the Detector Element Size (0054,1203), Value 1. The value of Transverse Mash (0054,1202) is the same regardless of whether the mashing was done during acquisition or reconstruction.

###### C.8.9.1.1.10 Energy Window Range Sequence

Multiple energy windows are allowed in order to allow coincidence events based on additional Energy Windows (e.g., Compton events scattered in the detector). All energy windows are assumed to contribute to all images in the PET Series.

###### C.8.9.1.1.11 Temporal Relationships of Images in PET Series

Figure C.8.9.1.1.11-1a and Figure C.8.9.1.1.11-1b show the temporal relationships of images within a PET Series.

Figure C.8.9.1.1.11-1a. Example DYNAMIC PET Series

Figure C.8.9.1.1.11-1b. Example GATED PET Series

#### C.8.9.2 PET Isotope Module

Table C.8-61 contains IOD Attributes that describe a PET Isotope.

Table C.8-61. PET Isotope Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Radiopharmaceutical Information Sequence | (0054,0016) | 2 | Sequence of Items that describe isotope information. Zero or more Items shall be included in this sequence.
>Radionuclide Code Sequence | (0054,0300) | 2 | Sequence that identifies the radionuclide. Zero or one item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4020 “PET Radionuclide”.
>Radiopharmaceutical Route | (0018,1070) | 3 | Route of administration.
>Administration Route Code Sequence | (0054,0302) | 3 | Sequence that identifies the administration route of the radiopharmaceutical. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 11 “Route of Administration”.
>Radiopharmaceutical Volume | (0018,1071) | 3 | Volume of administered radiopharmaceutical in cubic cm.
>Radiopharmaceutical Start Time | (0018,1072) | 3 | Time of start of administration. The actual time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as Series Time (0008,0031). The use of this Attribute is deprecated in favor of Radiopharmaceutical Start DateTime (0018,1078). ### Note The use of a time alone can cause confusion when the procedure spans midnight.
>Radiopharmaceutical Start DateTime | (0018,1078) | 3 | Date and time of start of administration. The actual date and time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as Series Time (0008,0031).
>Radiopharmaceutical Stop Time | (0018,1073) | 3 | Time of end of administration. The actual ending time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as Series Time (0008,0031). The use of this Attribute is deprecated in favor of Radiopharmaceutical Stop DateTime (0018,1079). ### Note The use of a time alone can cause confusion when the procedure spans midnight.
>Radiopharmaceutical Stop DateTime | (0018,1079) | 3 | Date and time of end of administration. The actual ending date and time of radiopharmaceutical administration to the patient for imaging purposes, using the same time base as Series Time (0008,0031).
>Radionuclide Total Dose | (0018,1074) | 3 | The radiopharmaceutical dose administered to the patient measured in Becquerels (Bq) at the Radiopharmaceutical Start Time (0018,1072). ### Note In other IODs, such as the NM IOD, this same attribute is specified in MegaBecquerels (MBq).
>Radiopharmaceutical Administration Event UID | (0008,3012) | 3 | Unique identification of the administration of the radiopharmaceutical to the patient. ### Note The UID is the same Radiopharmaceutical Administration Event UID that is in the Radiopharmaceutical Radiation Dose Report.
>Radionuclide Half Life | (0018,1075) | 3 | The radionuclide half life, in seconds, that was used in the correction of this image.
>Radionuclide Positron Fraction | (0018,1076) | 3 | The radionuclide positron fraction (fraction of decays that are by positron emission) that was used in the correction of this image.
>Radiopharmaceutical Specific Activity | (0018,1077) | 3 | The activity per unit mass of the radiopharmaceutical, in Bq/micromole, at the Radiopharmaceutical Start Time (0018,1072).
>Radiopharmaceutical | (0018,0031) | 3 | Name of the radiopharmaceutical.
>Radiopharmaceutical Code Sequence | (0054,0304) | 3 | Sequence that identifies the radiopharmaceutical. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4021 “PET Radiopharmaceutical”.
Intervention Drug Information Sequence | (0018,0026) | 3 | Sequence of Items that describes the intervention drugs used. One or more items are permitted in this sequence.
>Intervention Drug Name | (0018,0034) | 3 | Name of the intervention drug.
>Intervention Drug Code Sequence | (0018,0029) | 3 | Sequence that identifies the intervention drug name. Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 10 “Interventional Drug”.
>Intervention Drug Start Time | (0018,0035) | 3 | Time of administration of the intervention drug, using the same time base as for Series Time (0008,0031).
>Intervention Drug Stop Time | (0018,0027) | 3 | Time of completion of administration of the intervention drug, using the same time base as for Series Time (0008,0031).
>Intervention Drug Dose | (0018,0028) | 3 | Intervention drug dose, in mg.

#### C.8.9.3 PET Multi-gated Acquisition Module

Table C.8-62 contains IOD Attributes that describe a PET Multi-gated Acquisition.

Table C.8-62. PET Multi-Gated Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Beat Rejection Flag | (0018,1080) | 2 | Heart beat duration sorting has been applied. Enumerated Values: Y yes N no
Trigger Source or Type | (0018,1061) | 3 | Text indicating trigger source. Defined Terms: EKG
PVC Rejection | (0018,1085) | 3 | Description of the type of PVC rejection criteria used.
Skip Beats | (0018,1086) | 3 | Number of beats skipped after a detected arrhythmia.
Heart Rate | (0018,1088) | 3 | Average number of heart beats per minute for the collection period for this image. This shall include all accepted beats as well as rejected beats.
Cardiac Framing Type | (0018,1064) | 3 | Description of type of framing performed. See Section C.7.6.18.1.1.1 for description and Defined Terms.

#### C.8.9.4 PET Image Module

Table C.8-63 contains IOD Attributes that describe PET images.

Table C.8-63. PET Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.9.4.1.1 for specialization.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. This value shall be 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.9.4.1.2 for specialization.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. The value shall be the same as the value in Bits Allocated (0028,0100).
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Rescale Intercept | (0028,1052) | 1 | The value b in relationship between stored values (SV) and pixel value units (U) defined in Units (0054,1001): U = m*SV+b. The Rescale Intercept is always zero for PET images.
Rescale Slope | (0028,1053) | 1 | m in the equation specified in Rescale Intercept (0028,1052).
Frame Reference Time | (0054,1300) | 1 | The time that the pixel values in the image occurred. Frame Reference Time is the offset, in msec, from the Series reference time. See explanation in Section C.8.9.4.1.5.
Trigger Time | (0018,1060) | 1C | Time interval, in msec, from the start of the trigger to the beginning of data acquisition for this image. Required if Series Type (0054,1000), Value 1 is GATED.
Frame Time | (0018,1063) | 1C | Nominal duration per individual frame, in msec. Required if Series Type (0054,1000), Value 1 is GATED. See Section C.8.9.4.1.3 for explanation.
Low R-R Value | (0018,1081) | 1C | R-R interval lower limit for beat rejection, in msec. Required if Series Type (0054,1000), Value 1 is GATED and Beat Rejection Flag (0018,1080) is Y.
High R-R Value | (0018,1082) | 1C | R-R interval upper limit for beat rejection, in msec. Required if Series Type (0054,1000), Value 1 is GATED and Beat Rejection Flag (0018,1080) is Y.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5. Required if Lossy Compression has been performed on the image. May be present otherwise.
Image Index | (0054,1330) | 1 | An index identifying the position of this image within a PET Series. See Section C.8.9.4.1.9 for explanation.
Acquisition Date | (0008,0022) | 2 | The date the acquisition of data that resulted in this image started. See Section C.8.9.4.1.4 for specialization.
Acquisition Time | (0008,0032) | 2 | The time the acquisition of data that resulted in this image started. See Section C.8.9.4.1.4 for specialization.
Actual Frame Duration | (0018,1242) | 2 | Elapsed time of the data acquisition for this image, in msec. See Section C.8.9.4.1.6 for explanation.
Nominal Interval | (0018,1062) | 3 | Average duration of accepted beats, in msec, of the R-R interval.
Intervals Acquired | (0018,1083) | 3 | Number of heartbeats that fall within Low R-R Value (0018,1081) and High R-R Value (0018,1082), and were therefore accepted and contribute coincidence events to this R-R Interval.
Intervals Rejected | (0018,1084) | 3 | Number of heartbeats that fall outside Low R-R Value (0018,1081) and High R-R Value (0018,1082), and do not contribute coincidence events to this R-R Interval. However, they may contribute coincidence events to other R-R Intervals.
Primary (Prompts) Counts Accumulated | (0054,1310) | 3 | The sum of events that occur in the primary event channel. The counts include Trues +Scatter+ Randoms if Randoms Correction Method (0054,1100) is NONE; otherwise the counts are Trues +Scatter.
Secondary Counts Accumulated | (0054,1311) | 3 | Sum of counts accumulated in secondary channels. See Section C.8.9.4.1.7 for explanation.
Slice Sensitivity Factor | (0054,1320) | 3 | The slice-to-slice sensitivity correction factor that was used to correct this image. The value shall be one if no slice sensitivity correction was applied.
Decay Factor | (0054,1321) | 1C | The decay factor that was used to scale this image. Required if Decay Correction (0054,1102) is other than NONE. If decay correction is applied, all images in the Series shall be decay corrected to the same time.
Dose Calibration Factor | (0054,1322) | 3 | Factor that was used to scale this image from counts/sec to Bq/ml using a dose calibrator. The value shall be one if no dose calibration was applied. See Section C.8.9.4.1.8 for explanation.
Scatter Fraction Factor | (0054,1323) | 3 | An estimate of the fraction of acquired counts that were due to scatter and were corrected in this image. The value shall be zero if no scatter correction was applied.
Dead Time Factor | (0054,1324) | 3 | The average dead time correction factor that was applied to this image. The value shall be one if no dead time correction was applied.
Include Table 10-7 “General Anatomy Optional Macro Attributes” | No Context ID for the Anatomic Region Sequence is defined.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.

### Note

Referenced Overlay Sequence (0008,1130) and Referenced Curve Sequence (0008,1145) were previously included in this Module as optional Attributes but have been retired. See PS3.3-2004.

##### C.8.9.4.1 PET Image Module Attribute Descriptions

###### C.8.9.4.1.1 Image Type

For PET Images, Image Type (0008,0008) is specified to be Type 1.

### Note

For PET images, Image Type (0008,0008) Value 1 will be ORIGINAL for reconstructed images. DERIVED may be appropriate for some other results images. For PET images, Image Type (0008,0008) Value 2 will be PRIMARY.

###### C.8.9.4.1.2 Photometric Interpretation

Enumerated Values:

MONOCHROME2

See Section C.7.6.3.1.2 for definition of this term.

###### C.8.9.4.1.3 Frame Time

Frame Time (0018,1063) is the explicit duration of the gated frame when Cardiac Framing Type (0018,1064) is equal to FORW or BACK. Frame Time (0018,1063) is the nominal duration of the gated frame when Cardiac Framing Type (0018,1064) is equal to PCNT.

###### C.8.9.4.1.4 Acquisition Date, Acquisition Time

For PET Images, Acquisition Date (0008,0022) and Acquisition Time (0008,0032) are specified to be Type 2. Acquisition Date (0008,0022) and Acquisition Time (0008,0032) use the same time base as Series Time (0008,0031).

For Series Type (0054,1000) Value 1 equal to STATIC, WHOLE BODY, or DYNAMIC, Acquisition Time (0008,0032) is the real-world beginning of the accumulation of events into this Image. For STATIC, WHOLE BODY, or DYNAMIC Series, Acquisition Time (0008,0032) may vary from Image to Image within a PET Series.

For Series Type (0054,1000) Value 1 equal to GATED, Acquisition Time (0008,0032) is the real-world beginning of the capability of accumulating events into this Image. (The actual accumulation of events has only occurred during an R-R Interval.) For GATED Series, Acquisition Time (0008,0032) shall not vary from Image to Image within a PET Series.

###### C.8.9.4.1.5 Frame Reference Time

Frame Reference Time (0054,1300) is the time that the pixel values in the Image occurred. Frame Reference Time is defined as the time offset, in msec, from the Series Reference Time, where the Series Reference Time is defined by the combination of Series Date (0008,0021) and Series Time (0008,0031).

### Note

Frame Reference Time (0054,1300) is implementation dependent and may or may not be tied to any real-world event. To illustrate the meaning of Frame Reference Time (0054,1300), the following are some examples of possible implementations:

- Example 1: For a long-lived radionuclide and a non-time-varying radiopharmaceutical distribution, an implementation sets the Frame Reference Time (0054,1300) to the midpoint of the Actual Frame Duration (0018,1242).

- Example 2: For a short-lived radionuclide and a non-time-varying radiopharmaceutical distribution, an implementation sets the Frame Reference Time (0054,1300) to the time at which the average activity occurs for a decaying radionuclide, Tave. If image acquisition started at the Series Reference Time and the image has not been decay corrected, then Tave will be:

  where:

  - lambda = decay constant = (ln 2) / T1/2

  - T1/2 = Radionuclide Half Life (0018,1075)

  - T = Actual Frame Duration (0018,1242)

  Note that Tave will be sooner than the midpoint of the Actual Frame Duration (0018,1242).

- Example 3: For a short-lived radionuclide and a time-varying radiopharmaceutical distribution, an implementation with supplementary data (e.g., scanner count rates or blood sample data) sets the Frame Reference Time (0054,1300) to a derived time determined to be its best estimate of the time that the pixel values occurred.

###### C.8.9.4.1.6 Actual Frame Duration

The accumulation of counts for a PET Image shall occur entirely between:

1. the acquisition starting time (as specified by Acquisition Date (0008,0022) and Acquisition Time (0008,0032)), and

2. the acquisition ending time, which is equal to the acquisition starting time in (1) plus the Actual Frame Duration (0018,1242).

If Series Type (0054,1000) Value 1 is GATED, then the actual accumulation of counts has only occurred during an R-R Interval.

###### C.8.9.4.1.7 Secondary Counts Accumulated

Secondary Counts Accumulated (0054,1311) is multi-valued and, if supplied, has Values corresponding to the Secondary Counts Type (0054,1220). The number and order of the Values in Secondary Counts Accumulated (0054,1311) shall be the same as Secondary Counts Type (0054,1220).

###### C.8.9.4.1.8 Dose Calibration Factor

The Dose Calibration Factor (0054,1322) is the factor that was used to scale this image from counts/sec to Bq/ml using an external dose calibrator. The value shall be one if no dose calibration was applied. The application of a dose calibration correction is specified by Corrected Image (0028,0051) equal to DCAL.

### Note

Dose Calibration Factor (0054,1322) is not equal to the inverse of the sensitivity (kcps/Bq/ml) of the scanner, which is usually measured for a given radiopharmaceutical distribution and excluding the effects of attenuation.

###### C.8.9.4.1.9 Image Index

Image Index (0054,1330) is an index identifying the position of this image within a PET Series.

### Note

The scheme for encoding Image Index (0054,1330) is as follows. Images within a PET Series can be viewed as a multi-dimensional array whose possible dimensions include R-R Intervals, Time Slots, Time Slices, and Slices. The dimensions of the array are defined by Series Type (0054,1000) Value 1. Each dimension of the array has an index that identifies the position of this image in the array. The indices are: R-R Interval Index, Time Slot Index, Time Slice Index, Slice Index. The indices are calculated as follows:

Index | Range of Index | Order of Images along that Dimension
--- | --- | ---
R-R Interval Index | 1 to Number of R-R Intervals (0054,0061) | Increasing Low R-R Value (0018,1081)
Time Slot Index | 1 to Number of Time Slots (0054,0071) | Increasing Trigger Time (0018,1060)
Time Slice Index | 1 to Number of Time Slices (0054,0101) | Increasing Frame Reference Time (0054,1300)
Slice Index | 1 to Number of Slices (0054,0081) | If Series Type (0054,1000) Value 2 is IMAGE:Order is in increasing position along the normal, where the normal is determined by the cross product of the direction cosines of the row and column of the image. See Image Orientation (0020,0037) in the Image Plane Module. If Series Type (0054,1000) Value 2 is REPROJECTION:Order is in increasing or decreasing angle of the normal, where the normal is determined by the cross product of the direction cosines of the row and column of the image. See Image Orientation (0020,0037) in the Image Plane Module. (Note that reprojection images rotate about only a single axis as described in Section C.8.9.1.1.1. Therefore, all normals are co-planar and make a single angle with respect to each other.)

Using these index values the position of this image within the multi-dimensional array (Image Index (0054,1330)) is calculated as follows:

Series Type (0054,1000), Value 1 | Dimensions of Array (Last dimension is most rapidly changing) | Encoding of Image Index (0054,1330)
--- | --- | ---
STATIC | Slice | Slice Index
WHOLE BODY | Slice | Slice Index
DYNAMIC | Time Slice \Slice | ((Time Slice Index - 1) * (Number of Slices (0054,0081))) + Slice Index
GATED | R-R Interval \Time Slot \Slice | ((R-R Interval Index - 1) * (Number of Time Slots (0054,0071)) * (Number of Slices (0054,0081))) + ((Time Slot Index - 1) * (Number of Slices (0054,0081))) + Slice Index

#### C.8.9.5 PET Curve Module

Retired. See PS3.3-2004.

### C.8.10 Hardcopy Modules

Retired. See PS3.3-2004.

### C.8.11 DX Modules

#### C.8.11.1 DX Series Module

The Digital X-Ray IODs use the General Series module described in Section C.7.3.1, specialized by the DX Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of projection Digital X-Ray.

### Note

In an abstract sense, a series may be viewed from the perspective of an acquisition device or a display device.

In the former case, it is convenient to group images related by commonality of acquisition parameters, such as the imaging subject's physical relationship to the equipment (such as a patient lying in a particular position with respect to the equipment), a single acquisition initiation (such as an MR pulse sequence or spiral CT run), or a single workflow action on the part of the operator (such as the reading of a collection of CR plates from the same examination).

In the latter case, it is often convenient to organize images for viewing or browsing into series based upon other criteria such as physical or temporal proximity that may not necessarily correspond with the order or grouping in which the images were acquired.

This conflict is most apparent in the existing CR Image IOD Section C.8.1, where the definition of View Position at the Series Level in CR Series Section C.8.1.1 implies, for example, that a Lateral and PA Chest X-Ray may not be grouped into a single series. While this may be in keeping with the traditional CT and MR notions that a change in an imaging subject's physical orientation with respect to the imaging equipment implies a new series, it is most unnatural from the point of view of a reader viewing or browsing a collection of projection radiographic images.

A similar example pertains in the case of the traditional set of views of the maxillary and mandibular dentition, in which all the images are logically grouped in one sequence, but the imaging equipment moves with respect to the imaging subject, and the size of the detector may vary between images.

Accordingly, the constraint (apparent from the CT, MR and CR IODs) that a change in position, detector, body part or laterality implies a new series has been relaxed in the DX IODs, through the use of the DX Anatomy Imaged Module and the DX Positioning Module, which define Attributes at the Image level that specify these concepts with finer granularity. This approach is consistent with that used in the XA, XRF, US and NM IODs.

Images within a series are still required, if the Condition for the inclusion of the Frame of Reference Module is met, to be relative to the same Frame of Reference.

Table C.8-68 specifies the Attributes that identify and describe general information about the DX Series.

Table C.8-68. DX Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: DX PX IO MG See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Presentation Intent Type | (0008,0068) | 1 | Identifies the intent of the images that are contained within this Series. Enumerated Values: FOR PRESENTATION FOR PROCESSING See Section C.8.11.1.1.1 for further explanation.

##### C.8.11.1.1 DX Series Attribute Descriptions

###### C.8.11.1.1.1 Presentation Intent Type

Presentation Intent Type (0008,0068) shall identify the intent for the purposes of display or other presentation of all Images within this Series.

### Note

1. Since this is a Series level attribute, all Images within a Series have the same value for this Attribute.

2. The intent of this restriction is to ensure that FOR PRESENTATION and FOR PROCESSING images are placed in separate Series, so that no confusion can arise as to which images are suitable for diagnostic reading as determined by local policy.

A Series of Images intended for viewing by an observer, after application of any grayscale transformations specified in the image object such as VOI LUT, shall have an Enumerated Value of FOR PRESENTATION.

### Note

1. These images may still be of Image Type (0008,0008) ORIGINAL rather than DERIVED despite the possibility that they may have undergone some processing, such as unsharp masking. In this case a DERIVED image would have undergone yet further processing to make it substantially different from the original. See Figure C.8-13.

2. These images may still be subjected to processing or further processing, if appropriate, depending on the application.

3. These images are intended for display on a device, without (further) processing, since that device may not be capable of image processing. The quality of the displayed image or its suitability for any purpose is beyond the scope of the DICOM Standard.

Images that have been corrected to account for characteristics of the detector but are intended to be further processed before being displayed, shall have an Enumerated Value of FOR PROCESSING.

### Note

This type is provided to allow the functions of image acquisition and image processing for presentation to be separated and yet have images conveyed between the two processes using a DICOM object. Individual sites or users may choose to substitute their own specialized processing in place of that supplied by the implementer.

Images available at this stage of processing may be useful for quality control and problem solving purposes, as well as academic research.

Images of this type may also be archived, retrieved and processed with different algorithms or parameters in order to alter the appearance of specific features for clinical purposes.

The nature of the detector correction that may have been applied before sending an image of type FOR PROCESSING is not specified. In particular, acquisitions that acquire several sets of matrices of pixel values (such as image data, gain offset and a defect map) must perform some processing (detector correction) before a DX Image object can be instantiated.

The nature of the processing that may have been applied before sending an image of type FOR PRESENTATION is also not specified.

It is expected that individual implementers will use Private Attributes to convey specifics of the processing applied that may be of use for further processing by those aware of the parameters and algorithms. The diversity of detector types and processing algorithms make it undesirable to standardize such parameters.

Whether or not the spatial locations of all pixels are preserved during the processing of the source image that resulted in the current image can be indicated by Spatial Locations Preserved (0028,135A) in a Source Image Sequence (0008,2112) reference from the FOR PRESENTATION image to a FOR PROCESSING predecessor.

If images from the same exposure exist with different Values of Presentation Intent Type (0008,0068), then they shall have different SOP Instance UIDs.

### Note

1. Source Image Sequence (0008,2112) may be used to relate these images.

2. The SOP Class UIDs of the two images will also be different.

Figure C.8-13. Explanation of Presentation Intent Type

#### C.8.11.2 DX Anatomy Imaged Module

Table C.8-69 contains IOD Attributes that describe the anatomy contained in a DX IOD.

Table C.8-69. DX Anatomy Imaged Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Laterality | (0020,0062) | 1 | Laterality of (possibly paired) body part (as described in Anatomic Region Sequence (0008,2218)) examined. Enumerated Values: R right L left U unpaired B both left and right ### Note This Attribute is mandatory, in order to ensure that images may be positioned correctly relative to one another for display. Shall be consistent with any laterality information contained in Primary Anatomic Structure Modifier Sequence (0008,2230), if present. ### Note Laterality (0020,0060) is a Series level Attribute and must be the same for all Images in the Series, hence it must be absent.
Include Table 10-6 “General Anatomy Required Macro Attributes” | Defined CID for the Anatomic Region Sequence is 4009 for humans, and 7482 for animals. This is the anatomic region that is placed on the table or bucky for examination. ### Note It is strongly recommended that Anatomic Region Sequence (0008,2218) be sent with a value, in order to ensure that images may be positioned correctly relative to one another for display.

##### C.8.11.2.1 DX Anatomy Imaged Attribute Descriptions

The Attributes in this Module extend the function of Body Part Examined (0018,0015) as used in other IODs, and are intended to be used to facilitate the management of images and series in terms of routing, storage and display, as well as to dictate certain Conditions on Attributes and Modules in the DX IOD.

#### C.8.11.3 DX Image Module

Table C.8-70 contains IOD Attributes that describe a DX Image by specializing Attributes of the General Image and Image Pixel Modules, and adding additional Attributes.

Table C.8-70. DX Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.11.3.1.1 for specialization.
Samples per Pixel | (0028,0002) | 1 | Number of samples in this image. Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME1 MONOCHROME2
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Enumerated Values: 6 7 8 9 10 11 12 13 14 15 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Shall be one less than the value in Bit Stored (0028,0101).
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Enumerated Values: 0000H Unsigned Integer
Pixel Intensity Relationship | (0028,1040) | 1 | The relationship between the Pixel sample values and the X-Ray beam intensity. Enumerated Values: LIN Linearly proportional to X-Ray beam intensity LOG Logarithmically proportional to X-Ray beam intensity See Section C.8.11.3.1.2 for further explanation.
Pixel Intensity Relationship Sign | (0028,1041) | 1 | The sign of the relationship between the Pixel sample values stored in Pixel Data (7FE0,0010) and the X-Ray beam intensity. Enumerated Values: 1 Lower pixel values correspond to less X-Ray beam intensity -1 Higher pixel values correspond to less X-Ray beam intensity See Section C.8.11.3.1.2 for further explanation.
Rescale Intercept | (0028,1052) | 1 | The value b in the relationship between stored values (SV) in Pixel Data (7FE0,0010) and the output units specified in Rescale Type (0028,1054). Output units = m*SV + b. Enumerated Values: 0 See Section C.8.11.3.1.2 for further explanation.
Rescale Slope | (0028,1053) | 1 | m in the equation specified by Rescale Intercept (0028,1052). Enumerated Values: 1 See Section C.8.11.3.1.2 for further explanation.
Rescale Type | (0028,1054) | 1 | Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). Enumerated Values: US Unspecified See Section C.8.11.3.1.2 for further explanation.
Presentation LUT Shape | (2050,0020) | 1 | Specifies an identity transformation for the Presentation LUT, other than to account for the value of Photometric Interpretation (0028,0004), such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values - shall be used if Photometric Interpretation (0028,0004) is MONOCHROME2. INVERSE output after inversion is in P-Values - shall be used if Photometric Interpretation (0028,0004) is MONOCHROME1. See Section C.8.11.3.1.2 for further explanation.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Derivation Description | (0008,2111) | 3 | A text description of how this image was derived. See Section C.8.11.3.1.4 for further explanation.
Acquisition Device Processing Description | (0018,1400) | 3 | Indicates any visual processing performed on the images prior to exchange. See Section C.8.11.3.1.3 for further explanation.
Acquisition Device Processing Code | (0018,1401) | 3 | Code representing the device-specific processing associated with the image (e.g., Organ Filtering code) ### Note This Code is manufacturer specific but provides useful annotation information to the knowledgeable observer.
Patient Orientation | (0020,0020) | 1C | Patient direction of the rows and columns of the image. See Section C.7.6.1.1.1 for further explanation. Required if View Code Sequence (0054,0220) is not present or is present with an Item value other than (G-8300, SRT, "tissue specimen") or (G-8310, SRT, "tissue specimen from breast"). May be present otherwise.
Calibration Image | (0050,0004) | 3 | Indicates whether a reference object (phantom) of known size is present in the image and was used for calibration. Enumerated Values: YES NO Device is identified using the Device module. See Section C.7.6.12 for further explanation.
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: YES NO
VOI LUT Sequence | (0028,3010) | 1C | Defines a sequence of VOI LUTs. See Section C.8.11.3.1.5 for further explanation. One or more Items shall be included in this Sequence. Required if Presentation Intent Type (0008,0068) is FOR PRESENTATION and Window Center (0028,1050) is not present. May also be present if Window Center (0028,1050) is present.
>LUT Descriptor | (0028,3002) | 1 | Specifies the format of the LUT Data in this Sequence. See Section C.8.11.3.1.5 for further explanation.
>LUT Explanation | (0028,3003) | 3 | Free form text explanation of the meaning of the LUT.
>LUT Data | (0028,3006) | 1 | LUT Data in this Sequence.
Window Center | (0028,1050) | 1C | Defines a Window Center for display. See Section C.8.11.3.1.5 for further explanation. Required if Presentation Intent Type (0008,0068) is FOR PRESENTATION and VOI LUT Sequence (0028,3010) is not present. May also be present if VOI LUT Sequence (0028,3010) is present.
Window Width | (0028,1051) | 1C | Window Width for display. See Section C.8.11.3.1.5 for further explanation. Required if Window Center (0028,1050) is sent.
Window Center & Width Explanation | (0028,1055) | 3 | Free form explanation of the meaning of the Window Center and Width. Multiple values correspond to multiple Window Center and Width values.

##### C.8.11.3.1 DX Image Attribute Descriptions

###### C.8.11.3.1.1 Image Type

Value 1 shall identify the Pixel Data Characteristics in accordance with Section C.7.6.1.1.2 where the Enumerated Values are defined to be ORIGINAL or DERIVED.

### Note

DX images may still be of type ORIGINAL rather than DERIVED despite the possibility that they may have undergone some processing. In this case a DERIVED image would have undergone yet further processing to make it substantially different from the original.

Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2 where the Enumerated Values are defined to be PRIMARY or SECONDARY.

### Note

DX images generally use PRIMARY value for images captured from patient exposure.

If images from the same exposure exist with different Values of Image Type, then they shall have different SOP Instance UIDs.

### Note

Source Image Sequence (0008,2112) may be used to relate these images.

Value 3 (which is specific to the IOD) shall be present and have zero length (null value).

Other Values (4 and beyond) are optional and implementation specific.

###### C.8.11.3.1.2 Pixel Intensity Relationship and Grayscale Transformations

Pixel Intensity Relationship (0028,1040) and Pixel Intensity Relationship Sign (0028,1041) describe how the stored pixel values in Pixel Data (7FE0,0010) are related to the X-Ray beam intensity incident on the detector.

They do not define a transformation intended to be applied to the pixel data for presentation.

### Note

For example, if Pixel Intensity Relationship (0028,1040) is LIN and Pixel Intensity Relationship Sign (0028,1041) is -1, then lower values of Pixel Data (7FE0,0010) indicate higher X-Ray beam intensities corresponding to less radiographically dense regions projected on the image such as through air, and higher values of Pixel Data (7FE0,0010) indicate lower X-Ray beam intensities corresponding to more radiographically dense regions projected on the image such as through bone and radio-opaque contrast agents.

The transformation to be applied to the pixel data for presentation is defined by the successive application of the conceptual Modality LUT, the VOI Attributes and the conceptual Presentation LUT. This shall result in the output of P-Values.

Rescale Slope (0028,1053) and Rescale Intercept (0028,1052) define a linear subset of a conceptual Modality LUT transformation. For IODs that include this Module, these Attributes define an identity transformation. IODs that include the DX Image Module shall not include the Modality LUT Module.

The Presentation LUT Shape (2050,0020) defines a subset of a conceptual Presentation LUT. For IODs that include this Module, this Attribute defines an identity transformation or inverse identity transformation. IODs that include the DX Image Module shall not include the Presentation LUT Module.

Photometric Interpretation (0028,0004) indicates whether lower values that are the output of the VOI Attributes should be displayed as darker or lighter. Since the output of the equivalent of a conceptual Presentation LUT is in P-Values, which are defined in PS3.14 such that lower values correspond to lower luminance levels, then the definition of the Presentation LUT Shape (2050,0020), otherwise intended to be an identity transformation, must take into account the effect of the value specified for Photometric Interpretation (0028,0004).

### Note

Regardless of the values of Pixel Intensity Relationship (0028,1040) and Pixel Intensity Relationship Sign (0028,1041), the grayscale transformations to be applied to Pixel Data (7FE0,0010) are defined by the equivalent of the Modality LUT (Rescale Slope (0028,1053) and Rescale Intercept (0028,1052)), Value of Interest Attributes, Photometric Interpretation (0028,0004) and the equivalent of the Presentation LUT (Presentation LUT Shape (2050,0020)). However, the combination of the grayscale transformations and the description of the pixel intensity relationship, together define whether, for example, air is expected to be displayed as black or white.

###### C.8.11.3.1.3 Acquisition Device Processing Description

Acquisition Device Processing Description (0018,1400) provides some indication in human readable text of the digital processing on the images before exchange. Examples of this processing are: edge enhanced, subtracted, time filtered, gamma corrected, convolved (spatially filtered).

###### C.8.11.3.1.4 Derivation Description

If an Image is identified to be a Derived image in Image Type (0008,0008), Derivation Description (0008,2111) is an optional and implementation specific text description of the way the image was derived from an original image. As applied to DX images, it may be used to describe derivation operations such as edge enhancement, temporal filtering, digital subtraction, or other linear and non-linear transformations.

###### C.8.11.3.1.5 VOI Attributes

The Attributes of the VOI LUT Module (C.11.2) are specialized in the DX Image Module.

Window Center (0028,1050) and Window Width (0028,1051) specify a linear conversion (unless otherwise specified by the value of VOI LUT Function (0028,1056); See Section C.11.2.1.3) from the output of the (conceptual) Modality LUT values to the input to the (conceptual) Presentation LUT. Window Center contains the value that is the center of the window. Window Width contains the width of the window.

The application of Window Center (0028,1050) and Window Width (0028,1051) shall not produce a signed result.

### Note

If the Presentation LUT Shape (2050,0020) is IDENTITY, then the result of applying Window Center (0028,1050) and Window Width (0028,1051) is P-Values.

If multiple values are present, both Attributes shall have the same number of values and shall be considered as pairs. Multiple values indicate that multiple alternative views should be presented.

The VOI LUT Sequence specifies a (potentially non-linear) conversion from the output of the (conceptual) Modality LUT values to the input to the (conceptual) Presentation LUT.

If multiple items are present in VOI LUT Sequence (0028,3010), only one shall be applied. Multiple items indicate that multiple alternative views should be presented.

If any VOI LUT Attributes are included by an Image, a Window Width and Window Center or the VOI LUT Table, but not both,shall be applied to the Image for display. Inclusion of both indicates that multiple alternative views should be presented.

The three values of LUT Descriptor (0028,3002) describe the format of LUT Data (0028,3006).

The first value is the number of entries in the lookup table.

The second value is the first stored pixel value mapped. This pixel value is mapped to the first entry in the LUT. All image pixel values less than the first value mapped are also mapped to the first entry in the LUT Data. An image pixel value one greater than the first value mapped is mapped to the second entry in the LUT Data. Subsequent image pixel values are mapped to the subsequent entries in the LUT Data up to an image pixel value equal to number of entries + first value mapped - 1 that is mapped to the last entry in the LUT Data. Image pixel values greater than number of entries + first value mapped are also mapped to the last entry in the LUT Data.

The third value specifies the number of bits for each entry in the LUT Data (analogous to "bits stored"). It shall be between 10-16. The LUT Data shall be stored in a format equivalent to 16 "bits allocated" and "high bit" equal to "bits stored" - 1. The third value conveys the range of LUT entry values. These unsigned LUT entry values shall range between 0 and 2n-1, where n is the third value of the LUT Descriptor.

### Note

1. The third value is restricted in the VOI LUT Module to 8 or 16 but is specialized here.

2. The first and second values are not specialized and are the same as in the VOI LUT Module.

LUT Data (0028,3006) contains the LUT entry values.

#### C.8.11.4 DX Detector Module

Table C.8-71 contains IOD Attributes that describe a DX detector.

Table C.8-71. DX Detector Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
Detector Active Time | (0018,7014) | 3 | Time in mSec that the detector is active during acquisition of this image. ### Note This activation window overlaps the time of the X-Ray exposure as defined by Exposure Time (0018,1150) and Detector Activation Offset From Exposure (0018,7016).
Detector Activation Offset From Exposure | (0018,7016) | 3 | Offset time in mSec that the detector becomes active after the X-Ray beam is turned on during acquisition of this image. May be negative.
Field of View Shape | (0018,1147) | 3 | Shape of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). Enumerated Values: RECTANGLE ROUND HEXAGONAL
Field of View Dimension(s) | (0018,1149) | 3 | Dimensions in mm of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). If Field of View Shape (0018,1147) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of a circumscribed circle.
Field of View Origin | (0018,7030) | 1C | Offset of the TLHC of a rectangle circumscribing the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), before rotation or flipping, from the TLHC of the physical detector area measured in physical detector pixels as a row offset followed by a column offset. Required if Field of View Rotation (0018,7032) or Field of View Horizontal Flip (0018,7034) is present. See Section C.8.11.4.1.1 for further explanation.
Field of View Rotation | (0018,7032) | 1C | Clockwise rotation in degrees of Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), relative to the physical detector. Enumerated Values: 0 90 180 270 Required if Field of View Horizontal Flip (0018,7034) is present. See Section C.8.11.4.1.1 for further explanation.
Field of View Horizontal Flip | (0018,7034) | 1C | Whether or not a horizontal flip has been applied to the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), after rotation relative to the physical detector as described in Field of View Rotation (0018,7032). Enumerated Values: YES NO Required if Field of View Rotation (0018,7032) is present. See Section C.8.11.4.1.1 for further explanation.
Imager Pixel Spacing | (0018,1164) | 1 | Physical distance measured at the front plane of the detector housing between the center of each image pixel specified by a numeric pair - row spacing value(delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. The value of this attribute shall never be adjusted to account for correction for the effect of geometric magnification or calibration against an object of known size; Pixel Spacing (0028,0030) is specified for that purpose.
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Cassette ID | (0018,1007) | 3 | Identifier of the cassette that contains the photostimulable phosphor plate, for CR acquisitions.
Plate ID | (0018,1004) | 3 | Identifier of the photostimulable phosphor plate, for CR acquisitions.

Table C.8-71b contains common attributes that describe digital X-Ray detector.

Table C.8-71b. Digital X-Ray Detector Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Detector Type | (0018,7004) | 2 | The type of detector used to acquire this image. Defined Terms: DIRECT X-Ray photoconductor SCINTILLATOR Phosphor used STORAGE Storage phosphor FILM Scanned film/screen
Detector Configuration | (0018,7005) | 3 | The physical configuration of the detector. Defined Terms: AREA single or tiled detector SLOT scanned slot, slit or spot
Detector Description | (0018,7006) | 3 | Free text description of detector.
Detector Mode | (0018,7008) | 3 | Text description of operating mode of detector (implementation specific).
Detector ID | (0018,700A) | 3 | The ID or serial number of the detector used to acquire this image.
Date of Last Detector Calibration | (0018,700C) | 3 | The date on which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated.
Time of Last Detector Calibration | (0018,700E) | 3 | The time at which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated.
Exposures on Detector Since Last Calibration | (0018,7010) | 3 | Total number of X-Ray exposures that have been made on the detector used to acquire this image as identified in Detector ID (0018,700A) since it was calibrated.
Exposures on Detector Since Manufactured | (0018,7011) | 3 | Total number of X-Ray exposures that have been made on the detector used to acquire this image as identified in Detector ID (0018,700A) since it was manufactured.
Detector Time Since Last Exposure | (0018,7012) | 3 | Time in Seconds since an exposure was last made on this detector prior to the acquisition of this image.
Detector Binning | (0018,701A) | 3 | Number of active detectors used to generate a single pixel. Specified as number of row detectors per pixel then column.
Detector Manufacturer Name | (0018,702A) | 3 | Name of the manufacturer of the detector component of the acquisition system
Detector Manufacturer's Model Name | (0018,702B) | 3 | Model name of the detector component of the acquisition system
Detector Conditions Nominal Flag | (0018,7000) | 3 | Whether or not the detector is operating within normal tolerances during this image acquisition. Enumerated Values: YES NO ### Note This flag is intended to indicate whether or not there may have been some compromise of the diagnostic quality of the image due to some condition such as over-temperature, etc.
Detector Temperature | (0018,7001) | 3 | Detector temperature during exposure in degrees Celsius.
Sensitivity | (0018,6000) | 3 | Detector sensitivity in manufacturer specific units. ### Note This value is intended to provide a single location where manufacturer specific information can be found for annotation on a display or film, that has meaning to a knowledgeable observer. This value is manufacturer-specific. DICOM specifies standard Attributes in Table 10-23 'Exposure Index Macro', which are recommended.
Detector Element Physical Size | (0018,7020) | 3 | Physical dimensions of each detector element that comprises the detector matrix, in mm. Expressed as row dimension followed by column. ### Note This may not be the same as Detector Element Spacing (0018,7022) due to the presence of spacing material between detector elements.
Detector Element Spacing | (0018,7022) | 3 | Physical distance between the center of each detector element, specified by a numeric pair - row spacing value(delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. ### Note This may not be the same as the Imager Pixel Spacing (0018,1164), and should not be assumed to describe the stored image.
Detector Active Shape | (0018,7024) | 3 | Shape of the active area. Enumerated Values: RECTANGLE ROUND HEXAGONAL ### Note This may be different from the Field of View Shape (0018,1147), and should not be assumed to describe the stored image.
Detector Active Dimension(s) | (0018,7026) | 3 | Dimensions in mm of the active area. If Detector Active Shape (0018,7024) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of a circumscribed circle. ### Note This may be different from the Field of View Dimensions (0018,1149), and should not be assumed to describe the stored image.
Detector Active Origin | (0018,7028) | 3 | Offset of the TLHC of a rectangle circumscribing the active detector area from the TLHC of a rectangle circumscribing the physical detector area, measured in physical detector pixels as a row offset followed by a column offset. See Section C.8.11.4.1.1 for further explanation.
Include Table 10-23 “Exposure Index Macro Attributes” |

##### C.8.11.4.1 DX Detector Attribute Descriptions

###### C.8.11.4.1.1 Physical, Active, Field of View, Exposed and Displayed Areas

The relationship between the Physical Detector Area, the Active Detector Area, the Field of View (what is stored in Pixel Data (7FE0,0010)), the Exposed Area (after X-Ray Collimation) and the Displayed Area is illustrated in the following diagrams.

### Note

Some of these Attributes relate the image data to manufacturer specific characteristics of the detector that may be used for quality control purposes, e.g., correlation of image artifacts with a detector defect map, analysis of noise performance, etc.

The Displayed Area is defined in pixel coordinates relative to the stored image pixel values by the Attributes of the Display Shutter Module (see Section C.7.6.11). If this Module is not present or supported, then the Displayed Area is equal to the Field of View.

The Exposed Area is defined in pixel coordinates relative to the stored image pixel values by the Attributes of the X-Ray Collimator Module (see Section C.8.7.3).

For the Digital X-Ray IODs, the Field of View is usually rectangular in shape and usually has the same size as the stored Pixel Data (7FE0,0010). The shape and size of the Field of View and the spacing of the pixels are defined by the following Attributes:

- Field of View Shape (0018,1147),

- Field of View Dimensions (0018,1149),

- Imager Pixel Spacing (0018,1164),

- Rows (0028,0010),

- Columns (0028,0011).

In the case where the Field of View has the same size as the stored Pixel Data (7FE0,0010) the following relationships are verified:

If the Field of View Shape (0018,1147) attribute equals RECTANGLE:

- Field of View Dimensionsrow dimension = Imager Pixel Spacingrow spacing * Rows

- Field of View Dimensionscolumn dimension = Imager Pixel Spacingcolumn spacing * Columns

If the Field of View Shape (0018,1147) attribute equals ROUND or HEXAGONAL:

- Field of View Dimensionsdiameter = Imager Pixel Spacingrow spacing * Rows

- Field of View Dimensionsdiameter = Imager Pixel Spacingcolumn spacing * Columns

The following Attributes define the relationship of the Field of View to the Physical Detector Area:

- Field of View Origin (0018,7030),

- Field of View Rotation (0018,7032),

- Field of View Horizontal Flip (0018,7034).

For the Digital X-Ray IODs, the Active Area, i.e., that part of the detector matrix that was activated for this exposure, is usually rectangular in shape. The shape and size of the Active Area and the size and spacing of the detectors are defined by the following Attributes:

- Detector Active Shape (0018,7024),

- Detector Active Dimensions (0018,7026),

- Detector Element Physical Size (0018,7020),

- Detector Element Spacing (0018,7022).

### Note

1. The Detector Element Physical Size (0018,7020) and Detector Element Spacing (0018,7022) may be different if there are insensitive regions between each detector.

2. This model of description is not able to accurately describe multiple matrices of detectors that are "tiled" to produce a single image.

The following optional Attribute defines the relationship of the Active Area to the Physical Detector Area:

- Detector Active Origin (0018,7028).

In the case where the Field of View has the same size as the stored Pixel Data (7FE0,0010), the relationship between detectors and stored image pixels is defined by Detector Binning (0018,701A), which specifies how many detectors, in each of the row and column directions, contribute to (are pooled or averaged to form) a single stored image pixel.

### Note

1. Detector Binning (0018,701A) may have values less than one if sub-sampling is used to derive an image with higher spatial resolution than the detector matrix.

2. The detector binning results in the size of a stored image pixel being different from the contributing physical detector pixels. In this case it is important to notice that the Field Of View Origin (0018,7030) is defined with respect to the center of the detector element located at the TLHC of the Field of View.

3. For images where the Field of View describes an area not equal to the size (rows and columns) of the stored Pixel Data (7FE0,0010), Detector Binning (0018,701A) does not fully specify the relationship between the contributing physical detector pixels and the stored image pixels.

Figure C.8-14. Explanation of Digital Detector Attributes

Figure C.8-15. Explanation of Digital Detector Attributes

#### C.8.11.5 DX Positioning Module

Table C.8-72 contains IOD Attributes that describe the positioning used in acquiring Digital X-Ray Images.

Table C.8-72. DX Positioning Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Projection Eponymous Name Code Sequence | (0018,5104) | 3 | A Sequence that describes the radiographic method of patient, tube and detector positioning to achieve a well described projection or view. Only a single Item is permitted in this Sequence. Shall be consistent with the other Attributes in this Module, if present, but may more specifically describe the image acquisition.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 4012 “Projection Eponymous Name”.
Patient Position | (0018,5100) | 3 | Description of imaging subject's position relative to the equipment. See Section C.7.3.1.1.2 for Defined Terms and further explanation. If present, shall be consistent with Patient Gantry Relationship Code Sequence (0054,0414) and Patient Orientation Modifier Code Sequence (0054,0412).
View Position | (0018,5101) | 3 | Radiographic view of the image relative to the imaging subject's orientation. Shall be consistent with View Code Sequence (0054,0220). See Section C.8.11.5.1.1 for further explanation.
View Code Sequence | (0054,0220) | 3 | Sequence that describes the projection of the anatomic region of interest on the image receptor. ### Note It is strongly recommended that this Attribute be present, in order to ensure that images may be positioned correctly relative to one another for display. Shall be consistent with View Position (0018,5101). See Section C.8.11.5.1.1 for further explanation. Only a single Item is permitted in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 4010 “DX View”.
>View Modifier Code Sequence | (0054,0222) | 3 | View modifier. One or more Items are permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4011 “DX View Modifier”.
Patient Orientation Code Sequence | (0054,0410) | 3 | Sequence that describes the orientation of the patient with respect to gravity. See Section C.8.11.5.1.2 for further explanation. Only a single Item is permitted in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 19 “Patient Orientation”.
>Patient Orientation Modifier Code Sequence | (0054,0412) | 3 | Patient Orientation Modifier. Required if needed to fully specify the orientation of the patient with respect to gravity. Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 20 “Patient Orientation Modifier”.
Patient Gantry Relationship Code Sequence | (0054,0414) | 3 | Sequence that describes the orientation of the patient with respect to the gantry. Only a single Item is permitted in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 21 “Patient Equipment Relationship”.
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to the table, support or bucky side that is closest to the Imaging Subject, as measured along the central ray of the X-Ray beam. ### Note This definition is less useful in terms of estimating geometric magnification than a measurement to a defined point within the Imaging Subject, but accounts for what is realistically measurable in an automated fashion in a clinical setting. This measurement does not take into account any air gap between the Imaging Subject and the "front" of the table or bucky. If the detector is not mounted in a table or bucky, then the actual position relative to the patient is implementation or operator defined. This value is traditionally referred to as Source Object Distance (SOD). See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID). See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Estimated Radiographic Magnification Factor | (0018,1114) | 3 | Ratio of Source Image Receptor Distance (SID) over Source Object Distance (SOD).
Positioner Type | (0018,1508) | 2 | Defined Terms: CARM COLUMN MAMMOGRAPHIC PANORAMIC CEPHALOSTAT RIGID NONE ### Note The term CARM can apply to any positioner with 2 degrees of freedom of rotation of the X-Ray beam about the Imaging Subject. The term COLUMN can apply to any positioner with 1 degree of freedom of rotation of the X-Ray beam about the Imaging Subject.
Positioner Primary Angle | (0018,1510) | 3 | Position of the X-Ray beam about the patient from the RAO to LAO direction where movement from RAO to vertical is positive, if Positioner Type (0018,1508) is CARM. See Section C.8.7.5 for further explanation if Positioner Type (0018,1508) is CARM. See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Positioner Secondary Angle | (0018,1511) | 3 | Position of the X-Ray beam about the patient from the CAU to CRA direction where movement from CAU to vertical is positive, if Positioner Type (0018,1508) is CARM. See Section C.8.7.5 for further explanation if Positioner Type (0018,1508) is CARM. See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Detector Primary Angle | (0018,1530) | 3 | Angle of the X-Ray beam in the row direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted toward higher numbered columns. Negative values indicate that the X-Ray beam is tilted toward lower numbered columns. See Section C.8.7.5 for further explanation. See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Detector Secondary Angle | (0018,1531) | 3 | Angle of the X-Ray beam in the column direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted toward lower numbered rows. Negative values indicate that the X-Ray beam is tilted toward higher numbered rows. See Section C.8.7.5 for further explanation. See Section C.8.11.7 for explanation if Positioner Type (0018,1508) is MAMMOGRAPHIC.
Column Angulation | (0018,1450) | 3 | Angle of the X-Ray beam in degree relative to an orthogonal axis to the detector plane. Positive values indicate that the tilt is toward the head of the table. ### Note The detector plane is assumed to be parallel to the table plane. Only meaningful if Positioner Type (0018,1508) is COLUMN.
Table Type | (0018,113A) | 3 | Defined Terms: FIXED TILTING NONE
Table Angle | (0018,1138) | 3 | Angle of table plane in degrees relative to horizontal plane [Gravity plane]. Positive values indicate that the head of the table is upward. Only meaningful if Table Type (0018,113A) is TILTING.
Body Part Thickness | (0018,11A0) | 3 | The average thickness in mm of the body part examined when compressed, if compression has been applied during exposure.
Compression Force | (0018,11A2) | 3 | The compression force applied to the body part during exposure, measured in Newtons.
Paddle Description | (0018,11A4) | 3 | Description of the compression paddle, if compression was applied to the body part during exposure.

##### C.8.11.5.1 DX Positioning Attribute Descriptions

###### C.8.11.5.1.1 View Code Sequence

View Code Sequence (0054,0220) replaces the function of View Position (0018,5101), and describes the radiographic view of the image relative to the real-world patient orientation as described in Annex A “Explanation of Patient Orientation (Normative)” in PS3.17.

###### C.8.11.5.1.2 Patient Orientation Code Sequence

This Attribute is not related to Patient Orientation (0020,0020) and conveys a different concept entirely.

#### C.8.11.6 Mammography Series Module

Table C.8-73 specifies the Attributes that identify and describe general information about a Digital Mammography Series.

Table C.8-73. Mammography Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: MG See Section C.7.3.1.1.1 for further explanation.
Request Attributes Sequence | (0040,0275) | 3 | Sequence that contains attributes from the Imaging Service Request. One or more Items are permitted in this sequence.
>Include Table 10-9 “Request Attributes Macro Attributes” | For Reason for Requested Procedure Code Sequence (0040,100A) the Baseline CIDs are CID 6051 “Breast Procedure Reason” and CID 6055 “Breast Clinical Finding Or Indicated Problem”. No Baseline CIDs are defined for other Attributes. ### Note For example, Reason for Requested Procedure Code Sequence (0040,100A) may be used to convey whether the images in the Series were taken for screening or diagnostic purposes, if the information cannot be found in Reason For Performed Procedure Code Sequence (0040,1012) in the General Study Module.

#### C.8.11.7 Mammography Image Module

Table C.8-74 contains IOD Attributes that describe a Digital Mammography X-Ray Image including its acquisition and positioning.

Table C.8-74. Mammography Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.11.7.1.4 for specialization.
Positioner Type | (0018,1508) | 1 | Enumerated Values: MAMMOGRAPHIC NONE
Distance Source to Detector | (0018,1110) | 3 | Distance in mm from source to detector center on the chest wall line ### Note This value is traditionally referred to as Source Image Distance (SID). See Section C.8.11.7.1.1.
Distance Source to Patient | (0018,1111) | 3 | Distance in mm from source to the breast support side that is closest to the Imaging Subject, as measured along the X-Ray beam vector. ### Note This value is traditionally referred to as Source Object Distance (SOD). See notes for this attribute in Section C.8.11.5 DX Positioning Module. See Section C.8.11.7.1.1 for description of X-Ray beam vector.
Positioner Primary Angle | (0018,1510) | 3 | Signed position in degrees of the X-Ray beam vector in the coronal anatomical plane as if the patient were standing facing the equipment where vertical is zero.
Positioner Primary Angle Direction | (0018,9559) | 3 | The interpretation of the sign of the Positioner Primary Angle (0018,1510). Enumerated Values: CW Clockwise. Positioner Primary Angle movement is positive when movement is from vertical to the patient's right (with patient standing, facing equipment). CC Counter clockwise. Positioner Primary Angle is positive when movement is from vertical to the patient's left (with patient standing, facing the equipment). See Section C.8.31.2.1.
Positioner Secondary Angle | (0018,1511) | 3 | Position in degrees of the X-Ray beam vector in the sagittal anatomical plane as if the patient were standing where movement of the X-Ray source from anterior to posterior is positive, and vertical is zero.
Image Laterality | (0020,0062) | 1 | Laterality of the region examined. Enumerated Values: R right L left B both (e.g., cleavage)
Organ Exposed | (0040,0318) | 1 | Organ to which Organ Dose (0040,0316) applies. Enumerated Values: BREAST ### Note In the Mammography IOD, Organ Dose (0040,0316) refers to the mean glandular dose.
Breast Implant Present | (0028,1300) | 3 | Whether or not the imaged breast contains a breast implant regardless of the visibility of a breast implant in the Pixel Data. Enumerated Values: YES NO ### Note The value is expected to be YES for all images acquired on a breast that contains a breast implant, even when a breast implant is displaced during image acquisition.
Partial View | (0028,1350) | 3 | Indicates whether this image is a partial view, that is a subset of a single view of the breast. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not be a partial view. ### Note This may occur when a breast is larger than the active area of the detector. If this Attribute is present, its value shall be NO if there is a View Modifier Code Sequence (0054,0222) Item of value (R-102D6, SRT, "Magnification") or (R-102D7, SRT, "Spot Compression"). ### Note SRT is the preferred designator for SNOMED, but SNM3 is allowed for backward compatibility. See PS3.16.
Partial View Description | (0028,1351) | 3 | Free text description of the portion of the breast captured in a partial view image. This Attribute shall not be present if there is a View Modifier Code Sequence (0054,0222) Item of value (R-102D6, SRT, "Magnification") or (R-102D7, SRT, "Spot Compression"). ### Note SRT is the preferred designator for SNOMED, but SNM3 is allowed for backward compatibility. See PS3.16.
Partial View Code Sequence | (0028,1352) | 3 | Sequence that describes the portion or section of the breast captured in a partial view image. Only one or two Items are permitted in this sequence. See Section C.8.11.7.1.3. If this Attribute is absent, then the image may or may not be a partial view. This Attribute shall not be present if there is a View Modifier Code Sequence (0054,0222) Item of value (R-102D6, SRT, "Magnification") or (R-102D7, SRT, "Spot Compression"). ### Note SRT is the preferred designator for SNOMED, but SNM3 is allowed for backward compatibility. See PS3.16.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4005 “Partial View Section for Mammography”.
Include Table 10-5 “General Anatomy Mandatory Macro Attributes” | Defined CID for the Anatomic Region Sequence is CID 4013 “Anatomic Region for Mammography”.
View Code Sequence | (0054,0220) | 1 | Sequence that describes the projection of the anatomic region of interest on the image receptor. Only a single Item shall be included in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Defined CID 4014 “View for Mammography”.
>View Modifier Code Sequence | (0054,0222) | 2 | View modifier. Zero or more Items shall be included in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4015 “View Modifier for Mammography”.
Biopsy Target Sequence | (0018,2041) | 3 | Sequence that identifies the targets of a biopsy procedure. One or more Items are permitted in this sequence, where the coordinate system is the same for all Items within a pair of stereo images.
>Target UID | (0018,2042) | 1 | Unique identifier for the target. ### Note To identify the same target in corresponding minus and plus stereo images.
>Localizing Cursor Position | (0018,2043) | 1 | Coordinates of localizing cursor position with respect to pixels in the image specified by a column (delimiter) row pair. The values shall be in the range 0\0 (TLHC) to Columns\Rows (BRHC).
>Calculated Target Position | (0018,2044) | 1 | The calculated target position (x, y, z) in mm in an equipment relative right-handed coordinate system where the origin is under the central X-Ray beam at the chest wall, and a z value of zero is located at the surface that the breast is in contact with that is closest to the detector. X is parallel to the chest wall, y is positive toward the patient's nipple, and z is positive toward the X-Ray source.
>Displayed Z Value | (0018,2046) | 1 | The z value in mm displayed to the user at the time of biopsy. ### Note This may be the same as the z value of Calculated Target Position or different in direction or reference point, such as relative to the compression paddle. This is not the distance that the needle was inserted, particularly for a lateral (parallel) approach.
>Target Label | (0018,2045) | 3 | Target description.

##### C.8.11.7.1 Mammography Image Attribute Descriptions

###### C.8.11.7.1.1 Mammography X-Ray Beam and X-Ray Beam Vector Definition

Figure C.8.11.7-1 shows the X-Ray beam for a digital mammography system. The X-Ray beam vector is defined from the Focal Spot to the center of the chest wall line of the Image Detection device.

Figure C.8.11.7-1. X-Ray Beam for a Digital Mammography System

###### C.8.11.7.1.2 Detector Primary and Secondary Angles

Detector Angles are defined in a fashion similar to the positioner angles, except that the angle of the x-ray beam vector is relative to the detector plane rather than the patient plane. Zero degrees is referenced to the normal of the detector plane pointing toward the x-ray source. The valid range of the Detector Angles is -90 to + 90 degrees.

The Primary Axis of rotation is defined along the line in the column direction of the detector plane that intersects the x-ray beam vector. The Detector Primary Angle is defined in the plane perpendicular to the Primary Axis of rotation at the point where the x-ray beam vector intersects the detector plane, with zero degrees in the direction normal to the detector plane and +90 in the direction of the higher numbered columns of the detector in that plane. The valid range of Detector Primary Angle is -90 to +90 degrees.

The Secondary Axis is in the detector plane and is perpendicular to the Primary Axis at the intersection of the beam vector with the detector plane (i.e., it is along the row direction). The Detector Secondary Angle is defined in the plane perpendicular to the Secondary Axis at the point where the x-ray beam vector intersects the detector plane, with zero degrees in the direction normal to the detector plane. +90 degrees corresponds to the direction of the lower numbered rows of the detector in that plane. The Detector Secondary Angle range is -90 to + 90 degrees.

###### C.8.11.7.1.3 Partial View Code Sequence

Combinations of coded terms may be used in the Partial View Code Sequence (0028,1352) to express the breast section imaged. Figure C.8.11.7-2 shows examples for the right and left FB, XCC, XCCL and XCCM views, and Figure C.8.11.7-3 shows examples for the right and left ML, MLO, LM, LMO, SIO and ISO views.

Partial View Code Sequence Items (Code Meaning) | Partial View Images (A, B, C, D, E)
--- | ---
A) item 1 = Lateral B) item 1 = Medial |
A) item 1 = Posterior B) item 1 = Anterior |
A) item 1 = Lateral, item 2 = Posterior B) item 1 = Medial, item 2 = Posterior C) item1 = Anterior |
A) item 1 = Lateral, item 2 = Posterior B) item 1 = Medial, item 2 = Posterior C) item 1 = Lateral, item 2 = Anterior D) item 1 = Medial, item 2 = Anterior |
A) item 1 = Lateral, item 2 = Posterior B) item 1 = Central, item 2 = Posterior C) item 1 = Medial, item 2 = Posterior D) item 1 = Lateral, item 2 = Anterior E) item 1 = Medial, item 2 = Anterior |

Figure C.8.11.7-2. CC, FB, XCCL and XCCM partial views

### Note

If six images are required, then the "Central, Anterior" combination would be added.

Partial View Code Sequence Items (Code Meaning) | Partial View Images (A, B, C, D, E)
--- | ---
A) item 1 = Superior B) item 1 = Inferior |
A) item 1 = Posterior B) item 1 = Anterior |
A) item 1 = Superior, item 2 = Posterior B) item1 = Inferior, item 2 = Posterior C) item 1 = Anterior |
A) item 1 = Superior, item 2 = Posterior B) item 1 = Inferior, item 2 = Posterior C) item 1 = Superior, item 2 = Anterior D) item 1 = Inferior, item 2 = Anterior |
A) item 1 = Superior, item 2 = Posterior B) item 1 = Central, item 2 = Posterior C) item 1 = Inferior, item 2 = Posterior D) item 1 = Superior, item 2 = Anterior E) item 1 = Inferior, item 2 = Anterior |

Figure C.8.11.7-3. ML, MLO, LM, LMO, SIO and ISO partial views

### Note

If six images are required, then the "Central, Anterior" combination would be added.

###### C.8.11.7.1.4 Image Type

Image Type (0008,0008) Value 1 and Value 2 shall identify the Pixel Data Characteristics in accordance with Section C.8.11.3.1.1.

Value 3 shall be present and have zero length (null value), except when used to identify a stereotactic mammography image, digital breast tomosynthesis projection or generated 2D image, or contrast enhanced image.

### Note

In a previous version of PS3.3, Value 3 was required to be zero length (null value). If Value 3 is zero length, the image may or may not be a stereotactic mammography image, digital breast tomosynthesis projection or generated 2D image, or contrast enhanced image, if the Instance was created before these terms were defined.

The Enumerated Values for Value 3 of stereotactic mammography images are listed in Table C.8-74a.

Table C.8-74a. Enumerated Values of Image Type (0008,0008) Value 3 for Stereotactic Mammography

Enumerated Value | Definition | ACR MQCM Equivalent
--- | --- | ---
STEREO_SCOUT | A localizer image for a stereotactic acquisition. | …SC
STEREO_MINUS | The paired image obtained with the X-Ray source angle decreased from the scout position, to determine positioning coordinates prior to needle positioning. | …ST-
STEREO_PLUS | The paired image obtained with the X-Ray source angle increased from the scout position, to determine positioning coordinates prior to needle positioning. | …ST+
PREFIRE_MINUS | The paired image obtained with the X-Ray source angle decreased from the scout position, with the biopsy needle in position prior to needle deployment. | …PRF-
PREFIRE_PLUS | The paired image obtained with the X-Ray source angle increased from the scout position, with the biopsy needle in position prior to needle deployment. | …PRF+
POSTFIRE_MINUS | The paired image obtained with the X-Ray source angle decreased from the scout position, with the biopsy needle in position following needle deployment through the targeted lesion. | …POF-
POSTFIRE_PLUS | The paired image obtained with the X-Ray source angle increased from the scout position, with the biopsy needle in position following needle deployment through the targeted lesion. | …POF+
POSTBIOPSY_MINUS | The image obtained following tissue acquisition with the X-Ray source angle decreased from the scout position. | …POB-
POSTBIOPSY_PLUS | The image obtained following tissue acquisition with the X-Ray source angle increased from the scout position. | …POB+
POSTBIOPSY | The image obtained following tissue acquisition with the X-Ray source in the scout position. | …POB
POSTMARKER_MINUS | The image obtained following micromarker placement with the X-Ray source angle decreased from the scout position. | …POM-
POSTMARKER_PLUS | The image obtained following micromarker placement with the X-Ray source angle increased from the scout position. | …POM+
POSTMARKER | The image obtained following micromarker placement with the X-Ray source in the scout position. | …POM

The Enumerated Values for Value 3 of digital breast tomosynthesis projection images and mathematically generated 2D images are:

Table C.8-74b. Enumerated Values of Image Type (0008,0008) Value 3 for Digital Breast Tomosynthesis Projection and Generated 2D Images

Enumerated Value | Definition | ACR MQCM Equivalent
--- | --- | ---
TOMO_PROJ | Identifies the image as a digital breast tomosynthesis projection image. | n/a
TOMOSYNTHESIS | Identifies the image as digital breast tomosynthesis; shall be used only for generated 2D images when no other Value 3 takes precedence. | n/a
TOMO_SCOUT | A localizer image that may be used to determine positioning coordinates prior to needle positioning. | …SC
PREFIRE | The image obtained with the biopsy needle in position prior to needle deployment. | …PRF
POSTFIRE | The image obtained with the biopsy needle in position following needle deployment through the targeted lesion. | …POF
POSTBIOPSY | The image obtained following tissue acquisition with the X-Ray source in the scout position. | …POB
POSTMARKER | The image obtained following micromarker placement with the X-Ray source in the scout position. | …POM

### Note

Digital breast tomosynthesis projection images acquired as part of a biopsy procedure (and resulting derived images such as mathematically generated 2D) omit the _MINUS and _PLUS endings because a single digital breast tomosynthesis acquisition produces a set of projection images that replaces the _MINUS and _PLUS image pair used in conventional 2D breast biopsy imaging.

The Enumerated Values for Value 3 of contrast enhanced images are:

Table C.8-74c. Enumerated Values of Image Type (0008,0008) Value 3 for Contrast Enhanced Images

Enumerated Value | Definition
--- | ---
PRE_CONTRAST | Collected before contrast was administered.
POST_CONTRAST | Collected during or after contrast was administered.

If more than one characteristic (biopsy, tomosynthesis, contrast enhanced) applies to an image, Value 3 shall contain the biopsy image type. If biopsy is not involved, Value 3 shall contain the tomosynthesis image type.

### Note

For example, attributes of the Contrast/Bolus module may be used to identify contrast enhanced characteristics of a biopsy and/or tomosynthesis projection or generated 2D image that is also contrast enhanced.

Value 4 shall be present for images acquired using contrast enhanced digital x-ray imaging of the breast (but may be empty if none of the Defined Terms applies), and for mathematically generated 2D images. For other images Value 4 remains optional and implementation specific.

Table C.8-74d. Defined Terms of Image Type (0008,0008) Value 4 for Contrast Enhanced and Generated 2D Images

Enumerated Value | Definition
--- | ---
GENERATED_2D | Mathematically generated 2D view.
ADDITION | Created through Pixel by pixel addition operation.
SUBTRACTION | Created through Pixel by pixel subtraction operation.

If more than one characteristic (contrast enhanced, tomosynthesis) applies to an image, Value 4 shall contain the contrast enhanced image type. If contrast enhanced is not involved, Value 4 shall contain the generated 2D image type.

Value 5 shall be present for images acquired using contrast enhanced digital x-ray imaging of the breast, but may be empty if none of the Defined Terms applies. For non-contrast images Value 5 remains optional and implementation specific.

Table C.8-74e. Defined Terms of Image Type (0008,0008) Value 5 for Contrast Enhanced 2D Images

Enumerated Value | Definition
--- | ---
LOW_ENERGY | Low energy image.
HIGH_ENERGY | High energy image.

### Note

A recipient may use the different values for biopsy, tomosynthesis and contrast views to determine how to display them, for example in hanging protocols:

| Image Type Value 3 | Image Type Value 4 | Image Type Value 5
--- | --- | --- | ---
Conventional 2D mammography | empty | - | -
Stereotactic post-biopsy | POSTBIOPSY | - | -
Pre-contrast 2D | PRE_CONTRAST | empty | empty
Post-contrast 2D low energy | POST_CONTRAST | - | LOW_ENERGY
Post-contrast 2D addition | POST_CONTRAST | ADDITION | empty
Stereotactic scout pre-contrast | STEREO_SCOUT | empty | empty
Stereotactic stereo post-contrast high energy | STEREO_PLUS | empty | HIGH_ENERGY
Stereotactic post-fire post-contrast subtraction | POSTFIRE_MINUS | SUBTRACTION | empty
Tomosynthesis generated 2D | TOMOSYNTHESIS | GENERATED_2D | -
Tomosynthesis biopsy scout generated 2D | TOMO_SCOUT | GENERATED_2D | -
Tomosynthesis generated 2D post-contrast low energy | TOMOSYNTHESIS | GENERATED_2D | LOW_ENERGY
Tomosynthesis generated 2D post-contrast subtraction | TOMOSYNTHESIS | SUBTRACTION | empty
Tomosynthesis projection | TOMO_PROJ | - | -
Tomosynthesis projection post-biopsy | POSTBIOPSY | - | -
Tomosynthesis projection post-biopsy post-contrast subtraction | POSTBIOPSY | SUBTRACTION | empty

#### C.8.11.8 Intra-Oral Series Module

Table C.8-75 specifies the Attributes that identify and describe general information about a Digital Intra-Oral X-Ray Series.

Table C.8-75. Intra-Oral Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: IO See Section C.7.3.1.1.1 for further explanation.

#### C.8.11.9 Intra-Oral Image Module

Table C.8-76 contains IOD Attributes that describe a Digital Intra-Oral X-Ray Image including its acquisition and positioning.

Table C.8-76. Intra-Oral Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Positioner Type | (0018,1508) | 1 | Enumerated Values: NONE CEPHALOSTAT RIGID
Image Laterality | (0020,0062) | 1 | Laterality of the region examined. Enumerated Values: R right L left B both (i.e., midline)
Anatomic Region Sequence | (0008,2218) | 1 | Sequence that identifies the anatomic region of interest in this image. Only a single Item shall be included in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Defined CID 4016 “Anatomic Region for Intra-oral Radiography”.
>Anatomic Region Modifier Sequence | (0008,2220) | 1C | Sequence that refines the anatomic region of interest in this image. Required if Primary Anatomic Structure Sequence (0008,2228) is not sent. Only a single Item shall be included in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4017 “Anatomic Region Modifier for Intra-oral Radiography”.
Primary Anatomic Structure Sequence | (0008,2228) | 1C | Sequence that describes the primary anatomic structures of interest in this image. See Section C.8.11.9.1.1 for further explanation. Required if Anatomic Region Modifier Sequence (0008,2220) is not sent. One or more Items shall be included in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Defined CID 4018 “Primary Anatomic Structure for Intra-oral Radiography (permanent Dentition - Designation of Teeth)” or CID 4019 “Primary Anatomic Structure for Intra-oral Radiography (Deciduous Dentition - Designation of Teeth)”. See Section C.8.11.9.1.1 for further explanation.

##### C.8.11.9.1 Intra-Oral Image Attribute Descriptions

###### C.8.11.9.1.1 Primary Anatomic Structure Sequence

Code Value (0008,0100) shall be drawn from the DICOM Content Mapping Resource, CID 4018 “Primary Anatomic Structure for Intra-oral Radiography (permanent Dentition - Designation of Teeth)”, for permanent dentition, or CID 4019 “Primary Anatomic Structure for Intra-oral Radiography (Deciduous Dentition - Designation of Teeth)” for deciduous dentition.

These Context Groups correspond to ISO 3950-1984 that describes a designation of permanent and deciduous dentition using a two digit code, the first digit of which designates a quadrant, and the second digit a tooth.

The teeth imaged shall be listed as multiple Items in the Primary Anatomic Structure Sequence (0008,2228).

#### C.8.11.10 Enhanced Mammography Series Module

The Breast Tomosynthesis Image IOD uses the General Series module described in Section C.7.3.1, specialized by the Enhanced Mammography Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of a Breast Tomosynthesis device.

Table C.8-76b specifies the Attributes that identify and describe general information about the Enhanced Mammography Series.

Table C.8-76b. Enhanced Mammography Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: MG See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Request Attributes Sequence | (0040,0275) | 3 | Sequence that contains attributes from the Imaging Service Request. One or more Items are permitted in this sequence.
>Include Table 10-9 “Request Attributes Macro Attributes” | For Reason for Requested Procedure Code Sequence (0040,100A) the Baseline CIDs are CID 6051 “Breast Procedure Reason” and CID 6055 “Breast Clinical Finding Or Indicated Problem”. No Baseline CIDs are defined for other Attributes. ### Note For example, Requested Procedure Code Sequence (0040,100A) may be used to convey whether the images in the Series were taken for screening or diagnostic purposes.

### C.8.12 VL Modules and Functional Group Macros

#### C.8.12.1 VL Image Module

Table C.8-77 specifies the Attributes that describe a VL Image produced by Endoscopy (ES), General Microscopy (GM), Automated-Stage Microscopy (SM), External-camera Photography (XC), or other VL imaging Modalities.

Table C.8-77. VL Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.12.1.1.6 for specialization.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.12.1.1.1 for specialization of this Attribute.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See Section C.8.12.1.1.2 for specialization of this Attribute. See PS3.5 for further explanation.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. See Section C.8.12.1.1.2 for specialization of this Attribute. See PS3.5 for further explanation.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. See Section C.8.12.1.1.2 for specialization of this Attribute. See PS3.5 for further explanation.
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Each sample shall have the same pixel representation. See Section C.8.12.1.1.3 for specialization of this Attribute.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) per image. See Section C.8.12.1.1.4 for specialization of this Attribute.
Planar Configuration | (0028,0006) | 1C | Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See Section C.8.12.1.1.5 for specialization of this Attribute.
Content Time | (0008,0033) | 1C | The time the image pixel data creation started. Required if the Image is part of a series in which the images are temporally related. ### Note This Attribute was formerly known as Image Time.
Lossy Image Compression | (0028,2110) | 2 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5
Referenced Image Sequence | (0008,1140) | 1C | A Sequence that references other images significantly related to this image. One or more items are permitted in this sequence. Required if Image Type (0008,0008) Value 3 is present and has a value of "STEREO L" or "STEREO R". May also be present otherwise. See Section C.8.12.1.1.7.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 2 | Describes the purpose for which the reference is made. Zero or one item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7201 “Referenced Image Purposes of Reference”.
Window Center | (0028,1050) | 3 | Window Center for display. See Section C.11.2.1.2 for further explanation. Meaningful only if Photometric Interpretation (0028,0004) is MONOCHROME2.
Window Width | (0028,1051) | 1C | Window Width for display. See Section C.11.2.1.2 for further explanation. Required if Window Center (0028,1050) is present.
Anatomic Region Sequence | (0008,2218) | 1C | Sequence that identifies the anatomic region of interest in this image (i.e., external anatomy, surface anatomy, or general region of the body). Only a single Item shall be included in this sequence. Required if Number of Frames (0028,0008) is present and Specimen Description Sequence (0040,0560) is absent. May be present otherwise.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4040 “Endoscopy Anatomic Regions” is defined for the Video Endoscopic IOD. For other IODs, no Context ID is defined.
>Anatomic Region Modifier Sequence | (0008,2220) | 3 | Sequence of Items that modifies the anatomic region of interest of this image One or more Items are permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 2 “Anatomic Modifier”.
Include Table 10-8 “Primary Anatomic Structure Macro Attributes” | No Context ID is defined. These Type 3 Attributes are not appropriate when Specimen Description Sequence (0040,0560) is present, as it includes the Primary Anatomic Structure Macro for each specimen in the image.
Channel Description Code Sequence | (0022,001A) | 3 | Describes the light color used for each channel to generate the image. If Photometric Interpretation (0028,0004) has one of the YBR values, the meaning is for pixel data in an equivalent RGB encoding. ### Note Interpretation and representation of RGB images rely on the assumption that the red channel really contains the red wavelength range of illumination light, the blue channel the blue wavelength range, etc. Some modalities use the RGB Photometric Interpretation as a container representing 3 channels of any illumination wavelength. Shall have the same number of items as the value of Samples per Pixel (0028,0002). The channels shall be described in the order in which the channels are encoded.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4206 “Ophthalmic Channel Description”.
Pixel Spacing | (0028,0030) | 3 | Physical distance in the imaging target (patient or specimen) between the center of each pixel, specified as a numeric pair - adjacent row spacing \ adjacent column spacing, in mm. See Section 10.7.1.3.

##### C.8.12.1.1 VL Image Module Attribute Descriptions

###### C.8.12.1.1.1 Photometric Interpretation

Enumerated Values:

MONOCHROME2

RGB

YBR_FULL_422

YBR_PARTIAL_420

YBR_RCT

YBR_ICT

### Note

There is no formal color space defined, hence "false" color applications that encode near-visible light images may be encoded, for example, as RGB.

###### C.8.12.1.1.2 Bits Allocated, Bits Stored, and High Bit

Enumerated Values of Bits Allocated (0028,0100):

8

Enumerated Values of Bits Stored (0028,0101):

8

Enumerated Values of High Bit (0028,0102):

7

###### C.8.12.1.1.3 Pixel Representation

Enumerated Values:

0

###### C.8.12.1.1.4 Samples Per Pixel

Enumerated Values when Photometric Interpretation (0028,0004) is MONOCHROME2:

1

Enumerated Values when Photometric Interpretation (0028,0004) is RGB or YBR_FULL_422 or YBR_PARTIAL_420 or YBR_RCT or YBR_ICT:

3

###### C.8.12.1.1.5 Planar Configuration

This value shall be present if Samples per Pixel (0028,0002) has a value greater than 1.

Enumerated Values:

0

###### C.8.12.1.1.6 Image Type

The Image Type attribute identifies important image characteristics in a multiple valued data element. For Visible Light, Image Type is specialized as follows:

- Value 1 shall identify the Pixel Data Characteristics in accordance with Section C.7.6.1.1.2.

  Enumerated Values:

  ORIGINAL

  DERIVED

- Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2.

  Enumerated Values:

  PRIMARY

  SECONDARY

- Value 3 may be absent, but if present shall identify the members of a stereo pair, in which case Referenced Image Sequence (0008,1140) is used to identify the other member of the pair.

  Enumerated Values:

  STEREO L

    Image is the left image (relative to the observer's left) of a stereo pair acquisition

  STEREO R

    Image is the right image (relative to the observer's right) of a stereo pair acquisition

- Other Values are implementation specific (optional).

###### C.8.12.1.1.7 Referenced Image Sequence

When Image Type (0008,0008) Value 3 is STEREO L or STEREO R, Referenced Image Sequence (0008,1140) shall be used to identify the corresponding SOP Instance of the Stereoscopic acquisition. In this case, either:

- only a single item shall be present, or

- multiple items may be present, each with the Purpose of Reference Code Sequence (0040,A170) present, and only the first item having the Purpose of Reference value (121315, DCM, "Other image of stereoscopic pair").

#### C.8.12.2 Slide Coordinates Module

The table in this Section contains Attributes that describe Slide Coordinates. Slide Coordinates provide a means to locate an image within a given Frame of Reference.

### Note

1. A Frame of Reference (identified by a Frame of Reference UID) typically only applies to a single mounting of a slide on a particular microscope stage; there is no guarantee that a subsequent mounting of the slide, even on the same equipment, will allow reproducible positioning to the exact same location. These attributes allow consistent location of multiple images within the Series of a single Frame of Reference.

2. There is no a priori correspondence of pixels to Slide Coordinates. Therefore, the geometrical symmetry point through the pixel plane of the digital microscope may not correspond to the center of a pixel. The geometrical symmetry point could be between pixels.

3. This module formerly included a Type 3 attribute Pixel Spacing Sequence (0040,08D8), and subsidiary attributes; see PS3.3-2009. Pixel spacing is an attribute of the image acquisition, not the slide coordinates, and is inappropriate for this Module. It is now conveyed by Pixel Spacing (0028,0030) in the VL Image Module or the Pixel Measures Functional Group.

Table C.8-78. Slide Coordinates Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Center Point Coordinates Sequence | (0040,071A) | 2 | The coordinates of the center point of the Image in the Slide Coordinate System Frame of Reference. Zero or one item shall be included in this sequence. See Section C.8.12.2.1.1 for further explanation.
>X Offset in Slide Coordinate System | (0040,072A) | 1 | The X offset in millimeters from the Origin of the Slide Coordinate System. See Figure C.8-16.
>Y Offset in Slide Coordinate System | (0040,073A) | 1 | The Y offset in millimeters from the Origin of the Slide Coordinate System. See Figure C.8-16.
>Z Offset in Slide Coordinate System | (0040,074A) | 2 | The Z offset in microns from the image substrate reference plane (i.e., utilized surface of a glass slide).

##### C.8.12.2.1 Slide Coordinates Attribute Descriptions

###### C.8.12.2.1.1 Image Center Point Coordinates Sequence

This Section defines the Slide Coordinate System and specifies the Attributes that shall be used to describe the location of the center point of the Image pixel plane (as captured through a microscope) in the Slide Coordinate System Frame of Reference.

### Note

In Slide Microscopy (SM), the Microscope is equipped with a moveable Stage and position sensors that enable storage of the location of the center point of the displayed image with respect to the examined Specimen.

The Stage is the part of the Microscope to which the Slide is attached for viewing. The Objective Lens is the lens that is closest to the Specimen. The Top Surface of the Slide is the surface of the Slide on which the Specimen is mounted. The Bottom Surface of the Slide is the opposite surface. This Specification presumes that: 1) the Slide is rectangular; 2) the Top Surface of the Slide is oriented toward the Objective Lens of the Microscope; and 3) the Bottom Surface of the Slide is in perfect contact with the Microscope Stage when the Slide is attached to the Stage for viewing.

### Note

1. The Label of the Slide is presumed to be mounted-on or written-on the Top Surface of the Slide.

2. Specification of the mechanical form, function, or tolerances of the Microscope are outside the scope of this Standard.

Figure C.8-16 depicts the Top Surface of the Slide on the Microscope Stage from the perspective of the Objective Lens. This is Reference Slide Orientation. The X, Y, and Z axes of the Slide Coordinate System in Reference Slide Orientation are defined as follows. The Y-axis is a line that nominally represents the Left Edge of the Slide. The X-axis is a line that is orthogonal to the Y-axis and nominally represents the Specimen Edge of the Slide. The Z-axis is a line that passes through the intersection of the X-axis and Y-axis and is orthogonal to the Microscope Stage. The Origin (0,0,0) of the Slide Coordinate System is the point of intersection of the X, Y, and Z axes.

Figure C.8-16. Reference Slide Orientation

### Note

1. An improperly-placed coverslip or Specimen that overlaps an Edge of a Slide is not considered part of the Edge a Slide for purposes of defining the Slide Coordinate System. However, such objects may cause inaccurate positioning of the Slide on the Stage.

2. If the Left Edge and Specimen Edge of the Slide are not orthogonal (e.g., the Slide is damaged or defective or the Specimen Edge is curvilinear), then the lower left-hand corner of the Slide may not be located at the Origin.

3. The definitions of X, Y, and Z axes are the same for inverted microscopes, with the Top Surface of the slide (i.e., Specimen side of the Slide) still being closest to the Objective Lens.

4. The origin of a Frame of Reference is arbitrary (see Section C.7.4.1), but its nominal location for consistency of slide coordinates is defined in this section.

Figure C.8-17 depicts the Z-axis center point location. The X-axis value of Image Center Point Location (0040,073A) shall increase from the Origin toward the Right Edge in Reference Slide Orientation. The Y-axis value of Image Center Point Location (0040,073A) shall increase from the Origin toward the Label Edge in Reference Slide Orientation. The Z-axis value of Image Center Point Location (0040,073A) shall be nominally referenced as zero at the image substrate reference plane (i.e., the top surface of a glass slide) and shall increase in a positive fashion coincident with increased distance from the substrate surface.

Figure C.8-17. Z-Axis Center Point Location, View From Right Edge of Slide

#### C.8.12.3 VL Whole Slide Microscopy Series Module

Table C.8.12.3-1 specifies attributes for the VL Whole Slide Microscopy Series Module, including specialization of attributes in the General Series Module for use in the VL Whole Slide Microscopy Series Module.

Table C.8.12.3-1. VL Whole Slide Microscopy Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: SM See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.12.4 VL Whole Slide Microscopy Image Module

Table C.8.12.4-1 specifies the Attributes that describe the VL Whole Slide Microscopy Image Module.

Table C.8.12.4-1. VL Whole Slide Microscopy Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.12.4.1.1 for specialization.
Imaged Volume Width | (0048,0001) | 1 | Width of total imaged volume (distance in the direction of rows in each frame) in mm. See Section C.8.12.4.1.2
Imaged Volume Height | (0048,0002) | 1 | Height of total imaged volume (distance in the direction of columns in each frame) in mm. See Section C.8.12.4.1.2
Imaged Volume Depth | (0048,0003) | 1 | Depth of total imaged volume (distance in the Z direction of focal planes) in µm. See Section C.8.12.4.1.2
Total Pixel Matrix Columns | (0048,0006) | 1 | Total number of columns in pixel matrix; i.e., width of total imaged volume in pixels. See Section C.8.12.4.1.3
Total Pixel Matrix Rows | (0048,0007) | 1 | Total number of rows in pixel matrix; i.e., height of total imaged volume in pixels. See Section C.8.12.4.1.3
Total Pixel Matrix Origin Sequence | (0048,0008) | 1 | Location of pixel 1\1 of the total pixel matrix in the Slide Coordinate System Frame of Reference. Only a single Item shall be included in this sequence. See Section C.8.12.4.1.4 and Section C.8.12.2.1.1 for further explanation
>X Offset in Slide Coordinate System | (0040,072A) | 1 | The X offset in millimeters from the Origin of the Slide Coordinate System.
>Y Offset in Slide Coordinate System | (0040,073A) | 1 | The Y offset in millimeters from the Origin of the Slide Coordinate System.
Image Orientation (Slide) | (0048,0102) | 1 | The direction cosines of the first row and the first column of the total pixel matrix with respect to the Slide Coordinate System Frame of Reference. See Section C.8.12.4.1.4
Samples Per Pixel | (0028,0002) | 1 | Number of samples (color planes) per frame in this image. Enumerated Values: 1 3 See Section C.8.12.4.1.5 for further explanation.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.12.4.1.5 for Enumerated Values.
Planar Configuration | (0028,0006) | 1C | Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. Enumerated Values: 0 color-by-pixel
Number of Frames | (0028,0008) | 1 | Number of frames in a multi-frame image. Enumerated Values if Image Type (0008,0008) Value 3 is LOCALIZER or LABEL: 1
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Enumerated Values: 8 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Enumerated Values: 7 15
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. Enumerated Values: 0 unsigned integer
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started.
Acquisition Duration | (0018,9073) | 1 | Duration of the image acquisition in seconds.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1C | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values. Required if Photometric Interpretation (0028,0004) is MONOCHROME2.
Rescale Intercept | (0028,1052) | 1C | The value b in relationship between stored values (SV) and the output units. Output units = m*SV + b. Required if Photometric Interpretation (0028,0004) is MONOCHROME2. Enumerated Values: 0
Rescale Slope | (0028,1053) | 1C | m in the equation specified by Rescale Intercept (0028,1052). Required if Photometric Interpretation (0028,0004) is MONOCHROME2. Enumerated Values: 1
Volumetric Properties | (0008,9206) | 1 | Indication if geometric manipulations are possible with frames in the SOP Instance. See Section C.8.16.2.1.2. Enumerated Values: VOLUME pixels represent the volume specified for the image, and may be geometrically manipulated
Specimen Label in Image | (0048,0010) | 1 | Indicates whether the specimen label is captured in the image. Enumerated Values: YES NO
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient. Enumerated Values: YES NO ### Note If Specimen Label in Image (0048,0010) value is YES, Burned In Annotation (0028,0301) might be NO if the label includes only a specimen identifier and not patient identifying data.
Focus Method | (0048,0011) | 1 | Method of focusing image Enumerated Values: AUTO autofocus MANUAL includes any human adjustment or verification of autofocus
Extended Depth of Field | (0048,0012) | 1 | Image pixels were created through combining of image acquisition at multiple focal planes (focus stacking). Enumerated Values: YES NO
Number of Focal Planes | (0048,0013) | 1C | Number acquisition focal planes used for extended depth of field. Required if Extended Depth of Field (0048,0012) value is YES
Distance Between Focal Planes | (0048,0014) | 1C | Distance between acquisition focal planes used for extended depth of field, in µm. Required if Extended Depth of Field (0048,0012) value is YES
Acquisition Device Processing Description | (0018,1400) | 3 | Description of visual processing performed on the image prior to exchange. Examples of this processing are: edge enhanced, gamma corrected, convolved (spatially filtered)
Convolution Kernel | (0018,1210) | 3 | Label for convolution kernel used in acquisition device visual processing
Recommended Absent Pixel CIELab Value | (0048,0015) | 3 | A color value with which it is recommended to display the pixels of the Total Pixel Matrix that are not encoded. The units are specified in PCS-Values, and the value is encoded as CIELab. See Section C.10.7.1.1.

##### C.8.12.4.1 VL Whole Slide Microscopy Image Attribute Descriptions

###### C.8.12.4.1.1 Image Type

Image Type (0008,0008) is specified to be Type 1 with the following constraints:

Value 1 shall have a value of ORIGINAL or DERIVED

Value 2 shall have a value of PRIMARY

Value 3 (Image Flavor) shall have the Defined Terms in Table C.8.12.4-2.

Table C.8.12.4-2. VL Whole Slide Microscopy Image Flavors

LOCALIZER | Collected for the purpose of planning or navigating other images.
VOLUME | Set of frames that define a regularly sampled volume
LABEL | Purpose of image is to capture the slide label; any non-label area captured is incidental to that purpose.

Value 4 (Derived Pixel) shall have the Defined Terms specified in Table C.8.12.4-3.

Table C.8.12.4-3. VL Whole Slide Microscopy Derived Pixels

NONE | No derivation of pixels (original)
RESAMPLED | Pixels were derived by down sampling a higher resolution image

No additional values shall be present.

###### C.8.12.4.1.2 Imaged Volume Width, Height, Depth

The full physical extent of the whole slide image target volume is described in the attributes Imaged Volume Width (0048,0001), Imaged Volume Height (0048,0002), and Imaged Volume Depth (0048,0003). These values reflect the maximum extent in these dimensions. There is no requirement that this entire extent is actually encoded in frames of the Image SOP Instance.

The value of Imaged Volume Depth (0048,0003) shall not be 0. If only a single focal plane is imaged, the Imaged Volume Depth may be the optical depth of field as encoded in Slice Thickness (0018,0050) of the Pixel Measures Functional Group (see Section C.7.6.16.2.1).

###### C.8.12.4.1.3 Total Pixel Matrix Columns, Rows

Total Pixel Matrix Columns (0048,0006) and Total Pixel Matrix Rows (0048,0007) describe the size of the entire imaged volume as a single extent across all frames (tiles).

The extent would be as described in these attributes if the whole volume would be imaged and encoded as a non-sparse pixel matrix with the pixel spacing as specified in Pixel Spacing (0028,0030) of the Pixel Measures Functional Group (see Section C.7.6.16.2.1).

###### C.8.12.4.1.4 Total Pixel Matrix Origin Sequence and Image Orientation (slide)

Total Pixel Matrix Origin Sequence (0048,0008) specifies the location of the top leftmost pixel of the pixel matrix, and Image Orientation (Slide) (0048,0102) specifies the direction cosines of the first row and the first column of the pixel matrix, both with respect to the Slide Coordinate System Frame of Reference (see Section C.8.12.2). Although the image acquisition may vary the true row and column orientation at the pixel scale to account for local variation in the physical specimen, this attribute describes the orientation as if the Pixel Matrix were flat.

### Note

Typically, Image Orientation (Slide) will describe only a planar rotation, as the image plane is usually nominally parallel to the slide surface.

###### C.8.12.4.1.5 Photometric Interpretation and Samples Per Pixel

See Section C.7.6.3.1.2.

Enumerated Values for Photometric Interpretation (0028,0004):

MONOCHROME2

RGB

YBR_FULL_422

YBR_ICT

YBR_RCT

The value shall be appropriate to the compression transfer syntax used, if any, and shall be MONOCHROME2 or RGB for uncompressed or lossless compressed transfer syntaxes that do not involve color space transformations, YBR_ICT for irreversible JPEG 2000 transfer syntaxes, YBR_RCT for reversible JPEG 2000 transfer syntaxes, and YBR_FULL_422 for other lossy compressed transfer syntaxes.

### Note

Future lossless and lossy transfer syntaxes may lead to the need for new definitions and choices for Photometric Interpretation. The Enumerated Values may therefore be extended with additional Photometric Interpretation values directly associated with new transfer syntaxes that are negotiated, and hence do not render existing implementations non-conformant.

Multi-spectral images may be encoded as a single wavelength band (color) in each frame using MONOCHROME2, or with up to three bands in each frame using one of the color Photometric Interpretations.

Enumerated Values for Samples per Pixel (0028,0002) when Photometric Interpretation (0028,0004) is MONOCHROME2:

1

Enumerated Values for Samples per Pixel (0028,0002) when Photometric Interpretation (0028,0004) is not MONOCHROME2:

3

#### C.8.12.5 Optical Path Module

Table C.8.12.5-1 specifies the attributes of the optical paths used in the VL imaging. Each optical path is a combination of illumination, filters, lenses, and sensors, and each combination is identified for possible reference by attributes in other modules. Additional optical path parameters may be specified in the Acquisition Context Module.

Table C.8.12.5-1. Optical Path Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Optical Path Sequence | (0048,0105) | 1 | Describes the optical paths used during the acquisition of this image. One or more Items shall be included in this sequence. See Section C.8.12.5.1.1
>Optical Path Identifier | (0048,0106) | 1 | Identifier for the optical path specified in the Sequence Item. The identifier shall be unique for each Item within the Optical Path Sequence.
>Optical Path Description | (0048,0107) | 3 | Description of the optical path specified in the Sequence Item.
>Illuminator Type Code Sequence | (0048,0100) | 3 | Type of illuminator. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Illumination Wave Length | (0022,0055) | 1C | Nominal wavelength of the illuminator in nm. Required if Illumination Color Code Sequence (0048,ee08) is not present. May be present otherwise.
>Illumination Color Code Sequence | (0048,0108) | 1C | Color of the illuminator. Only a single Item shall be included in this sequence. Required if Illumination Wave Length (0022,0055) is not present. May be present otherwise.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Illumination Type Code Sequence | (0022,0016) | 1 | Coded value for illumination method. See Section C.8.12.5.1.2. One or more Items shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Light Path Filter Type Stack Code Sequence | (0022,0017) | 3 | Filters used in the light source (excitation) path. One or more Items are permitted in this sequence. See Section C.8.12.5.1.3.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Light Path Filter Pass-Through Wavelength | (0022,0001) | 3 | Nominal pass-through wavelength of light path filter(s) in nm
>Light Path Filter Pass Band | (0022,0002) | 3 | Pass band of light path filter(s) in nm. This Attribute has two Values. The first is the shorter and the second the longer wavelength relative to the peak. The values are for the - 3dB nominal (1/2 of peak) pass through intensity. One of the two Values may be zero length, in which case it is a cutoff filter.
>Image Path Filter Type Stack Code Sequence | (0022,0018) | 3 | Describes stack of filters used in image (emission) path between the imaging target and the optical sensor. One or more items are permitted in this sequence. See Section C.8.12.5.1.3.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Image Path Filter Pass-Through Wavelength | (0022,0003) | 3 | Nominal pass-through wavelength of image path filter(s) in nm
>Image Path Filter Pass Band | (0022,0004) | 3 | Pass band of image path filter(s) in nm. This Attribute has two Values. The first is the shorter and the second the longer wavelength relative to the peak. The values are for the - 3dB nominal (1/2 of peak) pass through intensity. One of the two Values may be zero length, in which case it is a cutoff filter
>Lenses Code Sequence | (0022,0019) | 3 | Lenses that were used in this optical path. One or more items are permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Condenser Lens Power | (0048,0111) | 3 | Nominal power of the condenser lens
>Objective Lens Power | (0048,0112) | 3 | Nominal power of the objective lens. If a single lens is used as both condenser and objective, its power is specified in this attribute.
>Objective Lens Numerical Aperture | (0048,0113) | 3 | Nominal numerical aperture of the objective lens.
>Channel Description Code Sequence | (0022,001A) | 1C | Describes the light color sensed for each channel to generate the image. Required if this differs from the natural interpretation. ### Note For MONOCHROME2, the natural interpretation is the full visible light spectrum. A full spectrum sensor may be presented with light of only a single color based on illumination and filters. Equipment may use a color Photometric Interpretation (RGB, YBR) as a container representing up to 3 channels of any detected wavelength. Shall have the same number of Items as the value of Samples per Pixel Used (0028,0003) if present, or otherwise the value of Samples per Pixel (0028,0002). The channels shall be described in the order in which the channels are encoded.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Context ID may be defined in the IOD constraints.
>Palette Color Lookup Table Sequence | (0048,0120) | 3 | For MONOCHROME2 images, provides a transform of the pixel values with this optical path into an RGB color representation. The LUT provides a mapping to an appropriate color or pseudo-color for display purposes. Only a single Item is permitted in this sequence.
>>Include Table C.7-22a “Palette Color Lookup Table Macro Attributes” |
>ICC Profile | (0028,2000) | 1C | An ICC Profile encoding the transformation of device-dependent stored pixel values into PCS-Values. See Section C.8.12.5.1.4 Required if Photometric Interpretation (0028,0004) is not MONOCHROME2, or if Palette Color Lookup Table Sequence (0048,0120) is present.

##### C.8.12.5.1 Optical Path Attribute Descriptions

###### C.8.12.5.1.1 Optical Path Sequence and Optical Path Identifier

The Optical Path Sequence (0048,0105) shall include an Item for every optical path used in the acquisition of the current image.

For single frame images that do not include the Multi-frame Functional Groups Module, this Sequence shall include only one Item.

For images that use the Multi-frame Functional Groups Module, the optical path associated with each frame is identified by reference to the Optical Path Identifier (0048,0106) of this Sequence (see Optical Path Identification Sequence (0048,0207) in Section C.8.12.6.2). The Optical Path Sequence may include Items for defined optical paths that are not referenced by any frame.

For Whole Slide Microscopy Image LOCALIZER images (see Section C.8.12.4.1.1 and Section C.8.12.7), all the optical paths associated with referenced images shall be described in Items of this Optical Path Sequence. The optical path associated with each referenced frame is identified in the Referenced Image Navigation Sequence (0048,0200) by reference to an Optical Path Identifier (0048,0106) of this Sequence. The Optical Path Identifiers used in the LOCALIZER image do not have to be identical to those used in the referenced images.

### Note

1. For example, each of four referenced images may use a different optical path (color), and within each of those image SOP Instances the single Optical Path Sequence Item is identified as "1", although the meaning of optical path "1" is different for each image. The LOCALIZER, however, must include all four optical paths with distinct identifiers "1", "2", "3", and "4".

2. The Optical Path Identifier is not necessarily numeric; it is a string of up to 16 characters (VR SH).

###### C.8.12.5.1.2 Illumination Type Code Sequence

Illumination Type Code Sequence (0022,0016) specifies the type of illumination of the imaging target. This attribute may include multiple Items, as some techniques may involve multiple methods, or some method identifiers may not be completely descriptive.

### Note

For example, this attribute might include two items, (111741, DCM, "Transmission illumination") and (111748, DCM, "Differential interference contrast") to indicate "Transmission DIC".

The type of illumination often prescribes the set of optical path components such as filters and prisms, and their arrangement in the optical path.

### Note

For instance, phase contrast illumination will utilize a condenser annulus and a phase contrast plate; this may be indicated by an item (111747, DCM, "Phase contrast illumination") in this attribute, but with no further specification in the filters and lenses identification attributes.

###### C.8.12.5.1.3 Light Path and Image Path Filter Type Stack Code Sequences

In some optical imaging methods, e.g., epifluorescence, there may be a single light path with its associated imaging components that is used in both illumination/excitation of the imaging target and in the transmitted/emitted path to the imaging sensor. In this case, the optical components are to be specified in the Image Path Filter Type Stack Code Sequence (0022,0018).

###### C.8.12.5.1.4 ICC Profile

ICC Profile (0028,2000) provides the transform for mapping stored color pixel values into ICC standard color Profile Connection Space (PCS). For MONOCHROME2 pixels that have a preferred color rendering through the Palette Color Lookup Table Sequence (0048,0120), this attribute provides a mapping of that preferred RGB color rendering into PCS. The ICC Profile shall follow the requirements specified in Section C.11.15.1.1.

#### C.8.12.6 Whole Slide Microscopy Functional Group Macros

The following sections contain Functional Group Macros specific to the VL Whole Slide Microscopy Image IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean "for all frames".

##### C.8.12.6.1 Plane Position (Slide) Macro

Table C.8.12.6.1-1 specifies the attributes of the Plane Position (Slide) Functional Group Macro.

Table C.8.12.6.1-1. Plane Position (Slide) Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Plane Position (Slide) Sequence | (0048,021A) | 1 | Describes position of frame in the Total Pixel Matrix and in the Slide Coordinate System Frame of Reference. Only a single Item shall be included in this Sequence.
>Column Position In Total Image Pixel Matrix | (0048,021E) | 1 | The column position of the top left hand pixel of the frame in the Total Pixel Matrix (see Section C.8.12.4.1.1). The column position of the top left pixel of the Total Pixel Matrix is 1.
>Row Position In Total Image Pixel Matrix | (0048,021F) | 1 | The row position of the top left hand pixel of the frame in the Total Pixel Matrix (see Section C.8.12.4.1.1). The row position of the top left pixel of the Total Pixel Matrix is 1.
>X Offset in Slide Coordinate System | (0040,072A) | 1 | The X offset in mm from the Origin of the Slide Coordinate System. See Figure C.8-16.
>Y Offset in Slide Coordinate System | (0040,073A) | 1 | The Y offset in mm from the Origin of the Slide Coordinate System. See Figure C.8-16.
>Z Offset in Slide Coordinate System | (0040,074A) | 1 | The Z offset in µm from the Origin of the Slide Coordinate System, nominally the surface of the glass slide substrate. See Figure C.8-17 ### Note Required even if only a single focal plane was acquired.

##### C.8.12.6.2 Optical Path Identification Macro

Table C.8.12.6.2-1 specifies the attributes of the Optical Path Identification Functional Group Macro.

Table C.8.12.6.2-1. Optical Path Identification Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Optical Path Identification Sequence | (0048,0207) | 1 | Identifies the optical path characteristics of this frame. Only a single Item shall be included in this sequence.
>Optical Path Identifier | (0048,0106) | 1 | Uniquely identifies the path described in the Optical Path Sequence (0048,0105) by reference to an Item with the same Optical Path Identifier (0048,0106) value. See Section C.8.12.5.

##### C.8.12.6.3 Specimen Reference Macro

Table C.8.12.6.3-1 specifies the attributes of the Specimen Reference Functional Group Macro. This allows association of the frame with specific specimens imaged on the same slide (e.g., tissue micro-arrays).

Table C.8.12.6.3-1. Specimen Reference Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Specimen Reference Sequence | (0048,0110) | 2 | Identifies specimens that may be visible in this frame, and are fully identified in the Specimen Description Sequence (0040,0560). Zero or more Items shall be included in this sequence.
>Specimen UID | (0040,0554) | 1 | Unique Identifier for Specimen. See Section C.7.6.22.1.2.

#### C.8.12.7 Multi-Resolution Navigation Module

Table C.8.12.7-1 specifies the Attributes that describe the Multi-Resolution Navigation Module, used in Whole Slide Microscopy LOCALIZER images.

Table C.8.12.7-1. Multi-Resolution Navigation Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Referenced Image Navigation Sequence | (0048,0200) | 1 | Identification of correspondence between areas of Pixel Data (07FE,0010) and frames of higher resolution images. One or more Items shall be included in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” | Referenced Image Instance
>Referenced Frame Number | (0008,1160) | 1 | Referenced Frame Number within Referenced Image. Only a single value shall be present.
>Top Left Hand Corner of Localizer Area | (0048,0201) | 1 | Top Left Hand Corner of Localizer image pixel area corresponding to referenced frame,specified as column\row. Column is the horizontal offset and row is the vertical offset.
>Bottom Right Hand Corner of Localizer Area | (0048,0202) | 1 | Bottom Right Hand Corner of Localizer image pixel area corresponding to referenced frame,specified as column\row. Column is the horizontal offset and row is the vertical offset.
>Pixel Spacing | (0028,0030) | 1 | Pixel Spacing in Referenced Image,specified as a numeric pair - adjacent row spacing \ adjacent column spacing, in mm.
>Z Offset in Slide Coordinate System | (0040,074A) | 1 | The Z offset of the referenced frame from the Slide Coordinates System reference plane, in microns
>Samples per Pixel | (0028,0002) | 1 | The number of samples (color planes) containing information in the referenced image.
>Optical Path Identifier | (0048,0106) | 1 | Identifies the optical path used in acquiring the referenced Frame by reference to an Item in the Optical Path Sequence (0048,0105) of the current SOP Instance. See Section C.8.12.5.

#### C.8.12.8 Slide Label Module

Table C.8.12.8-1 specifies the Attributes that describe the interpretation of a scanned Slide Label.

Table C.8.12.8-1. Slide Label Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Barcode Value | (2200,0005) | 2 | Barcode interpreted from the scanned slide label. ### Note This may be the same as Container Identifier (0040,0512).
Label Text | (2200,0002) | 2 | Label text interpreted from the scanned slide label, e.g., by optical character recognition.

### C.8.13 Enhanced MR Image

This section describes the specific modules for the Enhanced MR Image IOD.

#### C.8.13.1 Enhanced MR Image Module

This section describes the Enhanced MR Image Module.

Table C.8-79 specifies the attributes of the Enhanced MR Image module.

Table C.8-79. Enhanced MR Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table C.8-83 “MR Image and Spectroscopy Instance Macro Attributes” |
Image Type | (0008,0008) | 1 | Image characteristics. See Section C.8.16.1 and Section C.8.13.1.1.1.
Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
Include Table C.8-84 “MR Image Description Macro Attributes” |
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. For Enumerated Values See Section C.8.13.1.1.2.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values are specified in the IOD that invokes this Module. See Section C.7.6.3.1.2 for definition of this term.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. For Enumerated Values See Section C.8.13.1.1.2.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. For Enumerated Values See Section C.8.13.1.1.2.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Each sample shall have the same pixel representation. For Enumerated Values See Section C.8.13.1.1.2
Planar Configuration | (0028,0006) | 1C | Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See Section C.7.6.3.1.3 and Section C.8.13.1.1.2 for further explanation.
Spacing Between Slices | (0018,0088) | 3 | Value of the prescribed spacing to be applied between the slices in a volume that is to be acquired. The spacing in mm is defined as the center-to-center distance of adjacent slices.
Burned In Annotation | (0028,0301) | 1C | Indicates whether or not the image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO This means that images that contain this Module shall not contain such burned in annotations. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted), may be present otherwise.
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1C | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values. Required if Photometric Interpretation (0028,0004) is MONOCHROME2.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this Sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |

##### C.8.13.1.1 Enhanced MR Image Module Attribute Description

###### C.8.13.1.1.1 Image Type and Frame Type

Image Type (0008,0008) and Frame Type (0008,9007) are not included in this Macro but one or the other is always included in the Module or Macro that invokes this Macro, and they are therefore described here.

In addition to the requirements specified in Section C.8.16.1 Image Type and Frame Type, the following additional requirements and Defined Terms are specified.

###### C.8.13.1.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.13.1.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.13.1.1.1.3 Image Flavor

Table C.8-80 specifies the Defined Terms for MR additional to those defined in Section C.8.16.1.3 for Value 3 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-80. MR-Specific Image Type and Frame Type Value 3

Defined Term Name | Defined Term Description
--- | ---
ANGIO_TIME | Angio time acquisition (peripheral vascular/carotid)
ASL | Arterial Spin Labeling
CINE | Cardiac CINE
DIFFUSION | Collected to show diffusion effects.
DIXON | Dixon Water Fat Imaging Techniques.
FLOW_ENCODED | Flow Encoded
FLUID_ATTENUATED | Fluid Attenuated T2 weighted
FMRI | Collected for functional imaging calculations.
MAX_IP | Maximum Intensity Projection
MIN_IP | Minimum Intensity Projection
M_MODE | Image line over time
METABOLITE_MAP | Metabolite Maps from spectroscopy data
MULTIECHO | Multiple echoes with different contrast weighting (e.g., proton density and T2 weighted)
PROTON_DENSITY | Proton density weighted
REALTIME | Real-time collection of single slices
STIR | Short Tau Inversion Recovery
TAGGING | Images with superposition of thin saturation bands
TEMPERATURE | Images record temperature
T1 | T1 weighted
T2 | T2 weighted
T2_STAR | T2* weighted
TOF | Time Of Flight weighted
VELOCITY | Velocity encoded

###### C.8.13.1.1.1.4 Derived Pixel Contrast

Table C.8-81 specifies the Defined Terms for MR additional to those defined in Section C.8.16.1.4 for Value 4 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-81. MR-Specific Image Type and Frame Type Value 4

Defined Term Name | Defined Term Description
--- | ---
ADC | Apparent Diffusion Coefficient
DIFFUSION | Diffusion weighted
DIFFUSION_ANISO | Diffusion Anisotropy
DIFFUSION_ATTNTD | Diffusion Attenuated. Derived by removing the T2 contributions from a Diffusion Weighted image.
DIFFUSION_ISO | Isotropic images derived from Directional Diffusion images
FAT | Fat images derived using Dixon or other techniques
FAT_FRACTION | Fat Fraction images derived using Dixon or other techniques
FIELD_MAP | Field Map images derived using Dixon or other techniques
IN_PHASE | Water/Fat In Phase images derived using Dixon or other techniques
METABOLITE_MAP | Metabolite Maps from spectroscopy data
NEI | Created through Negative Enhancement Integral operation
OUT_OF_PHASE | Water/Fat Out of phase images derived using Dixon or other techniques
PERFUSION_ASL | Perfusion from an ASL series obtained by subtraction of control and label data
R_COEFFICIENT | R-Coefficient Map (fMRI)
R2_MAP | R2 Map
R2_STAR_MAP | R2* Map images derived using Dixon or other techniques
RHO | Proton Density map
SCM | Signal Change Map
SNR_MAP | Signal to Noise Map
T1_MAP | T1 Map
T2_STAR_MAP | T2* Map images derived using Dixon or other techniques
T2_MAP | T2 Map
TCS | Time Course of Signal
TEMPERATURE | Temperature encoded
VELOCITY | Velocity encoded
WATER | Water images derived using Dixon or other techniques
WATER_FRACTION | Water fraction images derived using Dixon or other techniques

###### C.8.13.1.1.2 Photometric Interpretation, Pixel Representation, Samples Per Pixel, Planar Configuration, Bits Allocated and Bits Stored

Table C.8-82 specifies the Enumerated Values and allowed combinations of Samples per Pixel (0028,0002), Planar Configuration (0028,0006), Pixel Representation (0028,0103), Bits Allocated (0028,0100) and Bits Stored (0028,0101) for each allowable Photometric Interpretation allowed by the IOD that invokes this Module.

Table C.8-82. Allowed Combinations of Attribute Values for Photometric Interpretation, Samples Per Pixel, Planar Configuration, Pixel Representation, Bits Allocated and Bits Stored

Photometric Interpretation | Samples per Pixel | Planar Configuration | Pixel Representation | Bits Allocated | Bits Stored
--- | --- | --- | --- | --- | ---
MONOCHROME2 | 1 | - | 0 or 1 | 8 | 8
MONOCHROME2 | 1 | - | 0 or 1 | 16 | 12, 16
RGB | 3 | 0 | 0 | 8 | 8
YBR_ICT | 3 | 0 | 0 | 8 | 8
YBR_RCT | 3 | 0 | 0 | 8 | 8
YBR_PARTIAL_420 | 3 | 0 | 0 | 8 | 8
YBR_FULL_422 | 3 | 0 | 0 | 8 | 8

###### C.8.13.1.1.3 Pixel Presentation

See Section C.8.16.2.1.1. No additional requirements or Defined Terms.

###### C.8.13.1.1.3.1 Supplemental Palette Color LUTs

See Section C.8.16.2.1.1.1.

###### C.8.13.1.1.4 Volumetric Properties

See Section C.8.16.2.1.2. No additional requirements or Defined Terms.

###### C.8.13.1.1.5 Volume Based Calculation Technique

See Section C.8.16.2.1.3. No additional requirements or Defined Terms.

#### C.8.13.2 MR Image and Spectroscopy Instance Macro

Table C.8-83 specifies the common attributes Enhanced MR Image Module and MR Spectroscopy Module.

Table C.8-83. MR Image and Spectroscopy Instance Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Acquisition Number | (0020,0012) | 3 | A number identifying the single continuous gathering of data over a period of time that resulted in this image. ### Note This number is not required to be unique across SOP Instances in a series. See also the description of the Referenced Raw Data Sequence (0008,9121).
Acquisition DateTime | (0008,002A) | 1C | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800). Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Acquisition Duration | (0018,9073) | 1C | The time in seconds needed to run the prescribed pulse sequence. See Section C.7.6.16.2.2.1 for further explanation. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Referenced Raw Data Sequence | (0008,9121) | 3 | The Raw data that was used to derive this Image. One or more Items are permitted in this Sequence. ### Note The items of in this sequence may identify raw data that has not been stored or encoded as a DICOM object. This allows recognition that images and spectra in different instances have been reconstructed from the same raw data.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Waveform Sequence | (0008,113A) | 3 | References to waveforms acquired in conjunction with this image. These Waveforms may or may not be temporally synchronized with this image. One or more Items are permitted in this Sequence.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Image Evidence Sequence | (0008,9092) | 1C | Full set of Composite SOP Instances referred to inside the Referenced Image Sequences of this Enhanced MR Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Source Image Evidence Sequence | (0008,9154) | 1C | Full set of Composite SOP Instances referred to inside the Source Image Sequences of this Enhanced MR Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Source Image Sequence (0008,2112) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Presentation State Sequence | (0008,9237) | 1C | References to Presentation State instances acquired in conjunction with this instance. ### Note May only be used to reference Presentation States belonging to the acquired data and not to reference Presentation States generated subsequently such as during interpretation. One or more Items shall be included in this sequence. Required if Presentation State is generated during acquisition, shall not be present otherwise.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Content Qualification | (0018,9004) | 1C | Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See Section C.8.13.2.1.1 for further explanation. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted), may be present otherwise.
Resonant Nucleus | (0018,9100) | 1C | Nucleus that is resonant at the transmitter frequency. Defined Terms: 1H 3HE 7LI 13C 19F 23NA 31P 129XE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
k-space Filtering | (0018,9064) | 1C | Describes k-space filtering applied. Shall be NONE if no k-space filter. Defined Terms: COSINE COSINE_SQUARED FERMI GAUSSIAN HAMMING HANNING LORENTZIAN LRNTZ_GSS_TRNSFM RIESZ TUKEY NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Magnetic Field Strength | (0018,0087) | 1C | Nominal field strength of the MR Magnet, in Tesla. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Applicable Safety Standard Agency | (0018,9174) | 1C | Agency that established MR safety standard applicable to the acquisition of this Instance. Defined Terms: IEC FDA MHW Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Applicable Safety Standard Description | (0018,9175) | 3 | Name and Version of the applicable standard.
Image Comments | (0020,4000) | 3 | User-defined comments about the image.
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.

##### C.8.13.2.1 MR Image and Spectroscopy Instance Macro Attribute Description

###### C.8.13.2.1.1 Content Qualification

Content Qualification (0018,9004) shall have the value PRODUCT if the content (image or Spectroscopy data) was produced with approved hardware and software. It shall have the value RESEARCH or SERVICE if there is any doubt as to whether the content was produced with approved hardware and software.

If data with Content Qualification (0018,9004) of RESEARCH or SERVICE is used to derive other content then it is expected that this derived content will also have Content Qualification (0018,9004) set to RESEARCH or SERVICE.

The intent of this element is to allow annotation of an advisory message that indicates that this content may not be suitable for clinical interpretation.

###### C.8.13.2.1.2 Evidence Sequence Attributes

The intent of the Referenced Image Evidence Sequence (0008,9092) and Source Image Evidence Sequence (0008,9154) is to provide a list of all unique SOP Instances listed in the Referenced Image Sequence (0008,1140) and Source Image Sequence (0008,2112) attributes respectively.

#### C.8.13.3 MR Image Description Macro

This section describes the MR Image Description Macro.

Table C.8-84 specifies the attributes of the MR Image Description Macro.

Table C.8-84. MR Image Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Complex Image Component | (0008,9208) | 1C | Representation of complex data of frames in the SOP Instance. See Section C.8.13.3.1.1 for a description and Defined Terms. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.
Acquisition Contrast | (0008,9209) | 1C | Indication of acquisition contrast used with frames in the SOP Instance. See Section C.8.13.3.1.2 for a description and Defined Terms. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). May be present otherwise.

##### C.8.13.3.1 MR Image Description Attribute Description

###### C.8.13.3.1.1 Complex Image Component

The value of Complex Image Component attribute (0008,9208) shall be used to indicate which component of the complex representation of the signal is represented in the pixel data.

Table C.8-85 specifies the Defined Terms for Complex Image Component (0008,9208).

Table C.8-85. Complex Image Component Attribute Values

Defined Term Name | Defined Term Description
--- | ---
MAGNITUDE | The magnitude component of the complex image data.
PHASE | The phase component of the complex image data.
REAL | The real component of the complex image data.
IMAGINARY | The imaginary component of the complex image data.
MIXED | Used only as a value in Complex Image Component (0008,9208) in the Enhanced MR Image Module if frames within the image SOP Instance contain different values for the Complex Image Component attribute in the MR Frame Type Functional Group.

###### C.8.13.3.1.2 Acquisition Contrast

Table C.8-86 specifies the Defined Terms for Acquisition Contrast (0008,9209).

Table C.8-86. Acquisition Contrast Values

Defined Term Name | Defined Term Description
--- | ---
DIFFUSION | Diffusion weighted contrast
FLOW_ENCODED | Flow Encoded contrast
FLUID_ATTENUATED | Fluid Attenuated T2 weighted contrast
PERFUSION | Perfusion weighted contrast
PROTON_DENSITY | Proton Density weighted contrast
STIR | Short Tau Inversion Recovery
TAGGING | Superposition of thin saturation bands onto image
T1 | T1 weighted contrast
T2 | T2 weighted contrast
T2_STAR | T2* weighted contrast
TOF | Time Of Flight weighted contrast
UNKNOWN | Value should be UNKNOWN if acquisition contrasts were combined resulting in an unknown contrast. Also this value should be used when the contrast is not known.
MIXED | Used only as a value in Acquisition Contrast (0008,9209) attribute in the Enhanced MR Image Type Module if frames within the image SOP Instance contain different values for the Acquisition Contrast attribute in the MR Frame Type Functional Group.

#### C.8.13.4 MR Pulse Sequence Module

The primary purpose of this module is to identify the pulse sequence and variations on that, which was used in creation of the image. Terminology is intended to be neutral, and allow equivalent sequences provided by different vendors to be classified the same.

Table C.8-87 specifies the attributes of the MR Pulse Sequence Module.

Table C.8-87. MR Pulse Sequence Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Pulse Sequence Name | (0018,9005) | 1C | Name of the pulse sequence for annotation purposes. Potentially vendor-specific name. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
MR Acquisition Type | (0018,0023) | 1C | Identification of spatial data encoding scheme. Defined Terms: 1D 2D 3D Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Echo Pulse Sequence | (0018,9008) | 1C | Echo category of pulse sequences. Enumerated Values: SPIN GRADIENT BOTH Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Multiple Spin Echo | (0018,9011) | 1C | Multiple Spin Echo category of pulse sequence used to collect different lines in k-space for a single frame. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and Echo Pulse Sequence (0018,9008) equals SPIN or BOTH. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and Echo Pulse sequence (0018,9008) equals SPIN or BOTH.
Multi-planar Excitation | (0018,9012) | 1C | Technique that simultaneously excites several volumes. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Phase Contrast | (0018,9014) | 1C | Phase Contrast Pulse sequence is a pulse sequence in which the flowing spins are velocity encoded in phase. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Velocity Encoding Acquisition Sequence | (0018,9092) | 1C | Velocity encoding directions used for acquisition. Required if Phase Contrast (0018,9014) equals YES. One or more Items shall be included in this sequence.
>Velocity Encoding Direction | (0018,9090) | 1 | The direction cosines of the velocity encoding vector with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
Time of Flight Contrast | (0018,9015) | 1C | Time of Flight contrast is created by the inflow of blood in the saturated plane. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Arterial Spin Labeling Contrast | (0018,9250) | 1C | Arterial Spin Labeling contrast technique. Enumerated Values: CONTINUOUS a single long low powered RF pulse PSEUDOCONTINUOUS multiple short low powered RF pulses PULSED a single short high powered RF pulse Required if Image Type (0008,0008) Value 3 is ASL. May be present otherwise.
Steady State Pulse Sequence | (0018,9017) | 1C | Steady State Sequence. Defined Terms: FREE_PRECESSION TRANSVERSE TIME_REVERSED LONGITUDINAL NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Echo Planar Pulse Sequence | (0018,9018) | 1C | Echo Planar category of Pulse Sequences. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Saturation Recovery | (0018,9024) | 1C | Saturation recovery pulse sequence. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Spectrally Selected Suppression | (0018,9025) | 1C | Spectrally Selected Suppression. Defined Terms: FAT WATER FAT_AND_WATER SILICON_GEL NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Oversampling Phase | (0018,9029) | 1C | Oversampling Phase. Enumerated Values: 2D phase direction 3D out of plane direction 2D_3D both NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Geometry of k-Space Traversal | (0018,9032) | 1C | Geometry category of k-Space traversal. Defined Terms: RECTILINEAR RADIAL SPIRAL Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Rectilinear Phase Encode Reordering | (0018,9034) | 1C | Rectilinear phase encode reordering. Defined Terms: LINEAR CENTRIC SEGMENTED REVERSE_LINEAR REVERSE_CENTRIC Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and Geometry of k-Space Traversal (0018,9032) equals RECTILINEAR. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and Geometry of k-Space Traversal (0018,9032) equals RECTILINEAR.
Segmented k-Space Traversal | (0018,9033) | 1C | Segmented k-Space traversal. If Geometry of k-Space Traversal is rectilinear, multiple lines can be acquired at one time. If Geometry of k-Space Traversal is spiral or radial, paths can be interleaved and acquired at one time. Enumerated Values: SINGLE successive single echo coverage PARTIAL segmented coverage FULL single shot full coverage Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Coverage of k-Space | (0018,9094) | 1C | Coverage of k-Space in the ky-kz plane. Defined Terms: FULL CYLINDRICAL ELLIPSOIDAL WEIGHTED Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and MR Acquisition Type (0018,0023) equals 3D. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and MR Acquisition Type (0018,0023) equals 3D.
Number of k-Space Trajectories | (0018,9093) | 1C | Number of interleaves or shots. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.

#### C.8.13.5 Enhanced MR Image Functional Group Macros

The following sections contain Functional Group Macros specific to the Enhanced MR Image IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".".

##### C.8.13.5.1 MR Image Frame Type Macro

Table C.8-88 specifies the attributes of the MR Image Frame Type Functional Group Macro.

Table C.8-88. MR Image Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Image Frame Type Sequence | (0018,9226) | 1 | Identifies the characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008), except that the value MIXED is not allowed unless the SOP Class UID is "1.2.840.10008.5.1.4.1.1.4.4" (Legacy Converted). See Section C.8.16.1 and Section C.8.13.1.1.1.
>Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
>Include Table C.8-84 “MR Image Description Macro Attributes” |

##### C.8.13.5.2 MR Timing and Related Parameters Macro

Table C.8-89 specifies the attributes of the MR Timing and Related Parameters Functional Group Macro.

Table C.8-89. MR Timing and Related Parameters Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Timing and Related Parameters Sequence | (0018,9112) | 1 | Identifies the timing and safety information of this frame. Only a single Item shall be included in this sequence.
>Repetition Time | (0018,0080) | 1C | The time in ms between two successive excitations of the same volume. Shall be 0 (zero) if there is a single excitation per volume. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Flip Angle | (0018,1314) | 1C | Steady state angle in degrees to which the magnetic vector is flipped from the magnetic vector of the primary field. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Echo Train Length | (0018,0091) | 1C | Number of lines in k-space acquired per excitation of the same volume regardless of the type of echo or the number of frames derived from them. See Section C.8.13.5.2.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>RF Echo Train Length | (0018,9240) | 1C | Number of RF echoes collected per RF shot (or excitation) per frame. A value of zero shall correspond to a pure gradient echo frame. Note that this value corresponds to the current frame. Several frames may be derived from the same shot. See Section C.8.13.5.2.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Gradient Echo Train Length | (0018,9241) | 1C | Number of gradient echoes collected per RF echo per shot (or excitation) per frame. A value of zero shall correspond to a pure RF echo frame. If RF Echo Train Length (0018,9240) is non zero and Gradient Echo Train Length is as well then only the central echo will be an RF Spin Echo, all others will be gradient echoes. See Section C.8.13.5.2.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Specific Absorption Rate Sequence | (0018,9239) | 1C | Sequence containing the methods of SAR calculation and the corresponding values. One or more Items shall be included in this sequence. Required if the system is capable of calculating Specific Absorption Rate (0018,9181).
>>Specific Absorption Rate Definition | (0018,9179) | 1 | Specification of the method of SAR calculation as defined in Applicable Safety Standard Description (0018,9174). Defined Terms: IEC_WHOLE_BODY IEC_PARTIAL_BODY IEC_HEAD IEC_LOCAL
>>Specific Absorption Rate Value | (0018,9181) | 1 | Specific Absorption Rate in W/kg.
>Gradient Output Type | (0018,9180) | 1C | Definition of gradient output unit, for which the value is stored in Gradient Output (0018,9182). Defined Terms: DB_DT in T/s ELECTRIC_FIELD in V/m PER_NERVE_STIM percentage of peripheral nerve stimulation Required if the system is capable of calculating Gradient Output (0018,9182).
>Gradient Output | (0018,9182) | 1C | Unit is defined by Gradient Output Type (0018,9180). Required if the system is capable of calculating Gradient Output (0018,9182).
>Operating Mode Sequence | (0018,9176) | 1C | Sequence of operating mode information relating to the frame/SOP instance as required to adhere to the Applicable Safety Standard Agency (0018,9174) regulations. One or more Items shall be included in this sequence. Required if required by law or regulations. May be present otherwise.
>>Operating Mode Type | (0018,9177) | 1 | Defined Terms: STATIC FIELD RF GRADIENT
>>Operating Mode | (0018,9178) | 1 | Operating mode applicable for the defined by the applicable standard. Defined Terms: IEC_NORMAL IEC_FIRST_LEVEL IEC_SECOND_LEVEL

###### C.8.13.5.2.1 RF Echo Train Length and Gradient Echo Train Length Attributes Usage

The three Echo Train Length attributes all specify information related to the pulse sequence, one or more frames, and the echo type. The following examples illustrate their usage.

For a sequence with each excitation/shot producing 2 spin echoes that produce a line of k-Space for 2 different frames, the following values would be used for each frame:

Echo Train Length | 2
Gradient Echo Train Length | 0
RF Echo Train Length | 1

For a sequence with each excitation/shot producing 2 gradient echoes that produce a line of k-Space for 2 different frames, the following values would be used:

Echo Train Length | 2
Gradient Echo Train Length | 1
RF Echo Train Length | 0

For a sequence with each excitation/shot producing 8 spin echoes that produce 8 lines of k-Space for 1 frame, the following values would be used:

Echo Train Length | 8
Gradient Echo Train Length | 0
RF Echo Train Length | 8

##### C.8.13.5.3 MR FOV/Geometry Macro

Table C.8-90 specifies the attributes of the MR FOV/Geometry Functional Group Macro.

Table C.8-90. MR FOV/Geometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR FOV/Geometry Sequence | (0018,9125) | 1 | Identifies the geometry parameters of this frame. Only a single Item shall be included in this sequence.
>In-plane Phase Encoding Direction | (0018,1312) | 1C | The axes of the in-plane phase encoding with respect to the frame. Enumerated Values: COLUMN ROW OTHER Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>MR Acquisition Frequency Encoding Steps | (0018,9058) | 1C | Number of Frequency Encoding steps (kx) acquired Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>MR Acquisition Phase Encoding Steps in-plane | (0018,9231) | 1C | Number of In-Plane Phase Encoding steps (ky) acquired Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>MR Acquisition Phase Encoding Steps out-of-plane | (0018,9232) | 1C | Number of Out-of-Plane Phase Encoding steps (kz) acquired Required if MR Acquisition Type (0018,0023) equals 3D and Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Percent Sampling | (0018,0093) | 1C | Fraction of acquisition matrix lines acquired, expressed as a percent. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Percent Phase Field of View | (0018,0094) | 1C | Ratio of field of view dimension in phase direction to field of view dimension in frequency direction, expressed as a percent. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

##### C.8.13.5.4 MR Echo Macro

Table C.8-91 specifies the attributes of the MR Echo Functional Group Macro.

Table C.8-91. MR Echo Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Echo Sequence | (0018,9114) | 1 | Identifies echo timing of this frame. Only a single Item shall be included in this sequence.
>Effective Echo Time | (0018,9082) | 1C | The time in ms between the middle of the excitation pulse and the peak of the echo produced for kx=0. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

##### C.8.13.5.5 MR Modifier Macro

Table C.8-92 specifies the attributes of the MR Modifier Functional Group Macro.

Table C.8-92. MR Modifier Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Modifier Sequence | (0018,9115) | 1 | Identifies general acquisition parameters of this frame. Only a single Item shall be included in this sequence.
>Inversion Recovery | (0018,9009) | 1C | Inversion Recovery preparatory sequence. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Inversion Times | (0018,9079) | 1C | Times in ms after the middle of inverting RF pulse to middle of excitation pulse to detect the amount of longitudinal magnetization. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Inversion Recovery (0018,9009) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Inversion Recovery (0018,9009) equals YES.
>Flow Compensation | (0018,9010) | 1C | Flow Compensation. Defined Terms: ACCELERATION VELOCITY OTHER NONE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Flow Compensation Direction | (0018,9183) | 1C | Flow Compensation Direction. Enumerated Values: PHASE FREQUENCY SLICE_SELECT SLICE_AND_FREQ SLICE_FREQ_PHASE PHASE_AND_FREQ SLICE_AND_PHASE OTHER Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Flow Compensation (0018,9010) equals other than NONE. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Flow Compensation (0018,9010) equals other than NONE.
>Spoiling | (0018,9016) | 1C | Spoiling. Enumerated Values: RF RF spoiled GRADIENT gradient spoiled RF_AND_GRADIENT NONE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Echo Pulse Sequence (0018,9008) equals GRADIENT or BOTH. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Echo Pulse Sequence (0018,9008) equals GRADIENT or BOTH.
>T2 Preparation | (0018,9021) | 1C | T2 prepared Pulse Sequence. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Spectrally Selected Excitation | (0018,9026) | 1C | Spectrally Selected Excitation. Enumerated Values: WATER water excitation FAT fat excitation NONE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Spatial Pre-saturation | (0018,9027) | 1C | Spatial Pre-saturation. Defined Terms: SLAB NONE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Partial Fourier | (0018,9081) | 1C | Partial Fourier. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Partial Fourier Direction | (0018,9036) | 1C | Direction of Partial Fourier. Enumerated Values: PHASE FREQUENCY SLICE_SELECT COMBINATION Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Partial Fourier (0018,9081) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Partial Fourier (0018,9081) equals YES.
>Parallel Acquisition | (0018,9077) | 1C | Parallel acquisition has been used to reduce measurement time. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Parallel Acquisition Technique | (0018,9078) | 1C | Parallel acquisition characteristics. Defined Terms: PILS SENSE SMASH OTHER Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Parallel Acquisition (0018,9077) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Parallel Acquisition (0018,9077) equals YES.
>Parallel Reduction Factor In-plane | (0018,9069) | 1C | Measurement time reduction factor expressed as ratio of original and reduced measurement time for the in-plane direction. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Parallel Acquisition (0018,9077) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Parallel Acquisition (0018,9077) equals YES.
>Parallel Reduction Factor out-of-plane | (0018,9155) | 1C | Measurement time reduction factor expressed as ratio of original and reduced measurement time for the out-of-plane direction Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Parallel Acquisition (0018,9077) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Parallel Acquisition (0018,9077) equals YES.
>Parallel Reduction Factor Second In-plane | (0018,9168) | 1C | Measurement time reduction factor expressed as ratio of original and reduced measurement time for the second in-plane direction. Only required for MR Spectroscopy SOP Instances. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Parallel Acquisition (0018,9077) equals YES. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Parallel Acquisition (0018,9077) equals YES.

##### C.8.13.5.6 MR Imaging Modifier Macro

Table C.8-93 specifies the attributes of the MR Imaging Modifier Functional Group Macro.

Table C.8-93. MR Imaging Modifier Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Imaging Modifier Sequence | (0018,9006) | 1 | Identifies sequence containing MR modifier Sequence Attributes. Only a single item shall be included in this sequence.
>Magnetization Transfer | (0018,9020) | 1C | Magnetization Transfer pulse sequence. Enumerated Values: ON_RESONANCE OFF_RESONANCE NONE Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Blood Signal Nulling | (0018,9022) | 1C | Blood Signal Nulling ("Black Blood") preparatory pulse sequence. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Tagging | (0018,9028) | 1C | Tagging. Defined Terms: GRID LINE NONE Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Tag Spacing First Dimension | (0018,9030) | 1C | Space between lines in mm. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Tagging (0018,9028) is GRID or LINE. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Tagging (0018,9028) is GRID or LINE.
>Tag Spacing Second Dimension | (0018,9218) | 1C | Space between the lines in mm in the other direction. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Tagging (0018,9028) is GRID. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Tagging (0018,9028) is GRID.
>Tag Angle First Axis | (0018,9019) | 1C | Angle of the tag lines relative to the rows axis (left to right) of the image, with a range of 0-180 degrees. The angle is increasing in clockwise direction. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Tagging (0018,9028) is GRID or LINE. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Tagging (0018,9028) is GRID or LINE.
>Tag Angle Second Axis | (0018,9219) | 1C | Angle of the tag lines relative to the rows axis (left to right) of the image, with a range of 0-180 degrees. The angle is increasing in clockwise direction. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Tagging (0018,9028) is GRID. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Tagging (0018,9028) is GRID.
>Tag Thickness | (0018,9035) | 1C | Thickness of the line in mm. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Tagging (0018,9028) is GRID or LINE. Otherwise may be present if Frame Type (0008,9007) Value 1 is DERIVED and Tagging (0018,9028) is GRID or LINE.
>Tagging Delay | (0018,9184) | 3 | Delay time in ms of the beginning of the application of the tagging pattern relative to the last R-peak.
>Transmitter Frequency | (0018,9098) | 1C | Center transmitter frequency in MHz. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Pixel Bandwidth | (0018,0095) | 1C | Reciprocal of the effective sampling period, in hertz per pixel. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.

##### C.8.13.5.7 MR Receive Coil Macro

Table C.8-94 specifies the attributes of the MR Receive Coil Functional Group Macro.

Table C.8-94. MR Receive Coil Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Receive Coil Sequence | (0018,9042) | 1 | A sequence that provides information about each receive coil used. Only a single Item shall be included in this sequence.
>Receive Coil Name | (0018,1250) | 1C | Name of receive coil used. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Receive Coil Manufacturer Name | (0018,9041) | 2C | Name of manufacturer of receive coil. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Receive Coil Type | (0018,9043) | 1C | Type of receive coil used. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise. Defined Terms: BODY VOLUME head, extremity, etc. SURFACE MULTICOIL
>Quadrature Receive Coil | (0018,9044) | 1C | Indicates whether the receive coil is quadrature. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise. Enumerated Values: YES quadrature or circularly polarized NO linear
>Multi-Coil Definition Sequence | (0018,9045) | 1C | A sequence that provides information regarding each element of a multi-coil. It should include attributes for all elements, whether used in the current acquisition or not. One or more Items shall be included in this sequence. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Receive Coil Type (0018,9043) equals MULTICOIL. May be present otherwise only if Receive Coil Type (0018,9043) equals MULTICOIL.
>>Multi-Coil Element Name | (0018,9047) | 1 | Name of element of multi-coil.
>>Multi-Coil Element Used | (0018,9048) | 1 | Indicates whether the multi-coil element was used in the current acquisition. Enumerated Values: YES NO
>Multi-Coil Configuration | (0018,9046) | 3 | A textual description of the configuration of multi-coil elements that was used in the current acquisition.

##### C.8.13.5.8 MR Transmit Coil Macro

Table C.8-95 specifies the attributes of the MR Transmit Coil Functional Group Macro.

Table C.8-95. MR Transmit Coil Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Transmit Coil Sequence | (0018,9049) | 1 | A sequence that provides information about the transmit coil used. Only a single Item shall be included in this sequence.
>Transmit Coil Name | (0018,1251) | 1C | Name of transmit coil used. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Transmit Coil Manufacturer Name | (0018,9050) | 2C | Name of manufacturer of transmit coil. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Transmit Coil Type | (0018,9051) | 1C | Type of transmit coil used. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise. Defined Terms: BODY VOLUME head, extremity, etc. SURFACE

##### C.8.13.5.9 MR Diffusion Macro

Table C.8-96 specifies the attributes of the MR Diffusion Functional Group Macro.

Table C.8-96. MR Diffusion Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Diffusion Sequence | (0018,9117) | 1 | Identifies the diffusion parameters of this frame. Only a single Item shall be included in this sequence.
>Diffusion b-value | (0018,9087) | 1C | Diffusion sensitization factor in sec/mm2. This is the actual b-value for original frames and those derived from frames with the same b-value, or the most representative b-value when derived from images with different b-values. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Diffusion Directionality | (0018,9075) | 1C | Specifies whether diffusion conditions for the frame are directional, or isotropic with respect to direction. Defined Terms: DIRECTIONAL BMATRIX ISOTROPIC NONE To be used when Frame Type (0008,9007) value 4 equals DIFFUSION_ANISO or Diffusion b-value (0018,9087) is 0 (zero). Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Diffusion Gradient Direction Sequence | (0018,9076) | 1C | Sequence containing orientations of all diffusion sensitization gradients that were applied during the acquisition of this frame. Only a single Item shall be included in this sequence. Required if Diffusion Directionality (0018,9075) equals DIRECTIONAL May be present if Diffusion Directionality (0018,9075) equals BMATRIX.
>>Diffusion Gradient Orientation | (0018,9089) | 1C | The direction cosines of the diffusion gradient vector with respect to the patient Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Diffusion b-matrix Sequence | (0018,9601) | 1C | The directional diffusion sensitization expressed as a 3x3 matrix with diagonal symmetry (with six unique elements from which the other elements can be derived). The rows and columns of the matrix are the X (right to left), Y (anterior to posterior) and Z (foot to head) patient-relative orthogonal axes as defined in Section C.7.6.2.1.1. The values are in units of ms/mm2. Only a single Item shall be included in this sequence. Required if Diffusion Directionality (0018,9075) equals BMATRIX.
>>Diffusion b-value XX | (0018,9602) | 1 | The value of b[X,X].
>>Diffusion b-value XY | (0018,9603) | 1 | The value of b[X,Y].
>>Diffusion b-value XZ | (0018,9604) | 1 | The value of b[X,Z].
>>Diffusion b-value YY | (0018,9605) | 1 | The value of b[Y,Y].
>>Diffusion b-value YZ | (0018,9606) | 1 | The value of b[Y,Z].
>>Diffusion b-value ZZ | (0018,9607) | 1 | The value of b[Z,Z].
>Diffusion Anisotropy Type | (0018,9147) | 1C | Class of diffusion anisotropy calculation. Defined Terms: FRACTIONAL RELATIVE VOLUME_RATIO Required if Frame Type (0008,9007) value 4 equals DIFFUSION_ANISO.

##### C.8.13.5.10 MR Averages Macro

Table C.8-97 specifies the attributes of the MR Averages Functional Group Macro.

Table C.8-97. MR Averages Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Averages Sequence | (0018,9119) | 1 | Identifies the averaging parameters of this frame. Only a single Item shall be included in this sequence.
>Number of Averages | (0018,0083) | 1C | Maximum number of times any point in k-space is acquired. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

##### C.8.13.5.11 MR Spatial Saturation Macro

Table C.8-98 specifies the attributes of the MR Spatial Saturation Functional Group Macro.

Table C.8-98. MR Spatial Saturation Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Spatial Saturation Sequence | (0018,9107) | 2 | A sequence that provides the position of spatial saturation bands deposited as part of the pulse sequence. Zero or more Items shall be included in this sequence.
>Slab Thickness | (0018,9104) | 1 | Thickness of slab in mm.
>Slab Orientation | (0018,9105) | 1 | The direction cosines of a normal vector perpendicular to the saturation plane with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
>Mid Slab Position | (0018,9106) | 1 | The x, y, and z coordinates of the midpoint of the slab plane in mm with respect to the patient. See Section C.7.6.2.1.1 for further explanation.

##### C.8.13.5.12 MR Metabolite Map Macro

Table C.8-99 specifies the attributes of the MR Metabolite Map Functional Group Macro.

Table C.8-99. MR Metabolite Map Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Metabolite Map Sequence | (0018,9152) | 1 | Describes the chemical shift parameters used to measure the resonant peaks from which the MR metabolite map represented by this frame was derived. Only a single Item shall be included in this sequence.
>Metabolite Map Description | (0018,9080) | 1C | Text describing the Metabolite Map. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Metabolite Map Code Sequence | (0018,9083) | 3 | When the measured peaks or their ratios can be related to metabolite substances, this sequence may be used to describe the metabolite substance whose resonant peaks are mapped in the Metabolite Map, or the ratio of substance resonant peaks that is mapped. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4032 “MR Spectroscopy Metabolites”.
>Chemical Shift Sequence | (0018,9084) | 3 | The list of frequencies that were used to create the Metabolite Map. One or more Items are permitted in this sequence.
>>Chemical Shift Minimum Integration Limit in ppm | (0018,9295) | 1 | Minimal value of Chemical Shift Frequency in ppm.
>>Chemical Shift Maximum Integration Limit in ppm | (0018,9296) | 1 | Maximum value of Chemical Shift Frequency in ppm.

##### C.8.13.5.13 MR Velocity Encoding Macro

Table C.8-100 specifies the attributes of the MR Velocity Encoding Functional Group Macro. This Functional Group contains the velocity encoding values as valid for the reconstructed Images, rather than for their acquisition. The velocity encoding directions for acquisition are described in the Velocity Encoding Acquisition Sequence (0018,9092) defined in the MR Pulse Sequence Module Section C.8.13.4.

Table C.8-100. MR Velocity Encoding Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Velocity Encoding Sequence | (0018,9197) | 1 | Identifies the velocity encoding of this frame. One or more Items shall be included in this sequence.
>Velocity Encoding Direction | (0018,9090) | 1C | The direction cosines of the velocity encoding vector with respect to the patient. See Section C.7.6.2.1.1 and Section C.8.13.5.13.1 for further explanation. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Velocity Encoding Minimum Value | (0018,9091) | 1C | Minimum velocity in cm/s. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Velocity Encoding Maximum Value | (0018,9217) | 1C | Maximum velocity in cm/s. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

###### C.8.13.5.13.1 Velocity Encoding Direction

The direction of the flow in a flow image is defined by the direction of the relevant flow vector in the MR Velocity Encoding Sequence (0018,9197).

The actual flow value (as specified in the Real World Value Mapping Sequence (0040,9096)) has a positive sign when the flow direction coincides with the Velocity Encoding Direction (0018,9090) vector.

##### C.8.13.5.14 MR Arterial Spin Labeling Macro

Table C.8-100b specifies the attributes of the MR Arterial Spin Labeling Functional Group Macro.

Table C.8-100b. MR Arterial Spin Labeling Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Arterial Spin Labeling Sequence | (0018,9251) | 1 | A sequence that provides the position of Arterial Spin Labeling regions deposited as part of the pulse sequence. One or more items shall be included in this sequence.
>ASL Technique Description | (0018,9252) | 2 | Text describing the used labeling technique in more detail.
>ASL Context | (0018,9257) | 1C | The purpose of the Arterial Spin Labeling. Enumerated Values: LABEL CONTROL M_ZERO_SCAN Required if Frame Type (0008,9007) is ORIGINAL. May be present otherwise. See Section C.8.13.5.14.1 for further explanation.
>ASL Slab Sequence | (0018,9260) | 1C | Sequence describing the ASL Slab geometry and anatomical region. One or more Items shall be included in this sequence. Required if ASL Context (0018,9257) is CONTROL or LABEL. May be present otherwise.
>>ASL Slab Number | (0018,9253) | 1 | Consecutive number identifying the different slabs used for labeling, starting with 1.
>>Include Table 10-7 “General Anatomy Optional Macro Attributes” | The anatomical region where the slab is positioned. Defined CID for the Anatomic Region Sequence (0008,2218) is CID 4030 “CT, MR and PET Anatomy Imaged”. Defined CID for Anatomic Region Modifier Sequence (0008,2220) and Primary Anatomic Structure Modifier Sequence (0008,2230) is CID 2 “Anatomic Modifier”.
>>ASL Slab Thickness | (0018,9254) | 1 | Thickness of slab in mm.
>>ASL Slab Orientation | (0018,9255) | 1 | The direction cosines of a normal vector perpendicular to the ASL slab with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
>>ASL Mid Slab Position | (0018,9256) | 1 | The x, y, and z coordinates of the midpoint of the slab in mm with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
>>ASL Pulse Train Duration | (0018,9258) | 1 | Duration (in milliseconds) of the Label or Control pulse. See Section C.8.13.5.14.3 for further explanation.
>ASL Crusher Flag | (0018,9259) | 1 | Indicates if an ASL Crusher Method has been used. Enumerated Values: YES NO See Section C.8.13.5.14.2 for further explanation.
>ASL Crusher Flow Limit | (0018,925A) | 1C | Maximum Flow Limit (in cm/s). Required if ASL Crusher Flag (0018,9259) is YES.
>ASL Crusher Description | (0018,925B) | 1C | Description of the ASL Crusher Method. Required if ASL Crusher Flag (0018,9259) is YES.
>ASL Bolus Cut-off Flag | (0018,925C) | 1 | Indicates if a Bolus Cut-off technique is used. Enumerated Values: YES NO
>ASL Bolus Cut-off Timing Sequence | (0018,925D) | 1C | Sequence that specifies the timing of the Bolus Cut-off technique and possibly its (scientific) description. Only a single Item shall be included in this sequence. Required if ASL Bolus Cut-off Flag (0018,925C) is YES.
>>ASL Bolus Cut-off Delay Time | (0018,925F) | 1 | Bolus Cut-off pulse delay time (in ms). See Section C.8.13.5.14.3 for further explanation.
>>ASL Bolus Cut-off Technique | (0018,925E) | 2 | Text describing the cut-off technique.

###### C.8.13.5.14.1 ASL Context

The attribute ASL Context (0018,9257) categorize the Original ASL images according to three contexts. This categorization allows post processing applications to select the correct type of image.

LABEL: Images are acquired with magnetically labeled arterial blood supply.

CONTROL: Images are acquired with a 'control' pulse in the proximal vessels.

M_ZERO_SCAN: Images are acquired with no label or control pulse in the proximal vessels.

###### C.8.13.5.14.2 ASL Crusher Flag

In order to quantify the perfusion accurately, it may be necessary to suppress signals within the macroscopic blood vessels (crushing). This can be used to separate the arterial input function from the brain parenchymal signal. The ASL Crusher Flag (0018,9259) indicates the application of an ASL crushing technique.

### Note

Frames with and without crushing may be present in one SOP Instance.

###### C.8.13.5.14.3 Relationship of ASL Timing Attributes

The general description of the ASL Acquisition technique requires a number of time related attributes that are depicted in Figure C.8.13.5.14-1.

Figure C.8.13.5.14-1. Attributes for Quantitative ASL

#### C.8.13.6 MR Series Module

The MR IODs use the General Series module described in Section C.7.3.1, specialized by the MR Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of MR device.

Table C.8-101 specifies the Attributes that identify and describe general information about the MR Series.

Table C.8-101. MR Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: MR See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

### C.8.14 MR Spectroscopy Modules

This section describes the MR Spectroscopy Modules.

### Note

Many attributes have names and descriptions that include the terms "pixel" and "image". Although MR spectroscopy is not pixel based, some of these "pixel" and "image" attributes encode concepts that are still relevant for this technique. Where such attributes appear in the MR Spectroscopy IOD, it may be helpful to consider the term "pixel" to be equivalent to a spectroscopy "voxel", and the term "image" to be equivalent to "MR Spectroscopy SOP Instance".

#### C.8.14.1 MR Spectroscopy Module

Table C.8-102 specifies the attributes of the MR Spectroscopy Module.

Table C.8-102. MR Spectroscopy Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table C.8-83 “MR Image and Spectroscopy Instance Macro Attributes” |
Image Type | (0008,0008) | 1 | Spectroscopy data characteristics. See Section C.8.14.5.1.1.
Include Table C.8-107 “MR Spectroscopy Description Macro Attributes” |
Transmitter Frequency | (0018,9098) | 1C | Precession frequency in MHz of the nucleus being addressed for each spectral axis. See Section C.8.14.1.1 for further explanation of the ordering. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Spectral Width | (0018,9052) | 1C | Spectral width in Hz. See Section C.8.14.1.1 for further explanation of the ordering. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Chemical Shift Reference | (0018,9053) | 1C | The chemical shift at the transmitter frequency in ppm. See Section C.8.14.1.1 for further explanation of the ordering. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Volume Localization Technique | (0018,9054) | 1C | Name of volume localization technique used. Shall be "NONE" if no spatial localization was performed. Defined Terms: ILOPS ISIS PRIME PRESS SLIM SLOOP STEAM NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Volume Localization Sequence | (0018,9126) | 1C | A sequence of Items that provide the position of RF excitations used to select a volume of tissue. The selected volume is described by the intersection of the sequence Items. One or more Items shall be included in this sequence. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and Volume Localization Technique (0018,9054) is other than NONE. May be present if Volume Localization Technique (0018,9054) is other than NONE.
>Slab Thickness | (0018,9104) | 1 | Thickness of slab in mm.
>Slab Orientation | (0018,9105) | 1 | The direction cosines of a normal vector perpendicular to the selection plane with respect to the patient. See Section C.7.6.2.1.1 for further explanation.
>Mid Slab Position | (0018,9106) | 1 | The x, y, and z coordinates of the mid-point of the slab in mm. See Section C.7.6.2.1.1 for further explanation.
De-coupling | (0018,9059) | 1C | Indicates whether de-coupling was active. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
De-coupled Nucleus | (0018,9060) | 1C | Nucleus being de-coupled. Defined Terms: 1H 3HE 7LI 13C 19F 23NA 31P 129XE See Section C.8.14.1.1 for further explanation of the ordering. Required if De-coupling (0018,9059) equals YES.
De-coupling Frequency | (0018,9061) | 1C | The center frequency (Hz) for the de-coupling. See Section C.8.14.1.1 for further explanation of the ordering. Required if De-coupling (0018,9059) equals YES.
De-coupling Method | (0018,9062) | 1C | The de-coupling modulation scheme used. Defined Terms: MLEV WALTZ NARROWBAND Required if De-coupling (0018,9059) equals YES.
De-coupling Chemical Shift Reference | (0018,9063) | 1C | The chemical shift in ppm at the de-coupling frequency. See Section C.8.14.1.1 for further explanation of the ordering. Required if De-coupling (0018,9059) equals YES.
Time Domain Filtering | (0018,9065) | 1C | Describes time domain filtering or apodization applied. Shall be NONE if no filtering operations were applied to the time domain data. Defined Terms: COSINE COSINE_SQUARED EXPONENTIAL GAUSSIAN HAMMING HANNING LORENTZIAN LRNTZ_GSS_TRNSFM NONE See Section C.8.14.1.1 for further explanation of the ordering. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Number of Zero Fills | (0018,9066) | 1C | Number of zero fills added to the time domain data before FT. Shall be 0 (zero) if no zero filling performed. See Section C.8.14.1.1 for further explanation of the ordering. See Section C.8.14.1.2 for further explanation on Zero Fills. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Baseline Correction | (0018,9067) | 1C | Describes baseline correction techniques. Shall be NONE if no baseline correction was performed. Defined Terms: LINEAR_TILT LOCAL_LINEAR_FIT POLYNOMIAL_FIT SINC_DECONVOLUTN TIME_DOMAIN_FIT SPLINE NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Frequency Correction | (0018,9101) | 1C | Specifies whether operations were performed to correct resonant frequency of metabolite peaks due to B0 field inhomogeneities. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
First Order Phase Correction | (0018,9198) | 1C | Describes whether a first order (frequency dependent) phase correction was applied to the spectral data. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Water Referenced Phase Correction | (0018,9199) | 1C | Indicates if the images or spectra were created using Water Reference time domain data for phase correction. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise. See Section C.8.14.1.3 for relation between Water Reference data and other Spectroscopic objects.
Water Referenced Acquisition | (0018,9297) | 3 | Describes the relation to Water Reference data for this instance. Enumerated Values: WATER_REFERENCE USED_DISCARDED REFERENCED NONE See Section C.8.14.1.4 for description of enumerated values.
Referenced Instance Sequence | (0008,114A) | 1C | References to SOP Instances significantly related to the current SOP Instance, including water reference data. Required if Water Reference Acquisition (0018,9297) equals REFERENCED. May be present otherwise. One or more Items shall be present in this Sequence.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Defined CID 7215 “Spectroscopy Purpose of Reference”.

##### C.8.14.1.1 MR Spectroscopy Attribute Multiplicity Ordering

The following attributes may have a Value Multiplicity of one or two depending whether one or two frequency axes are used as specified by the value of Data Point Rows (0028,9001):

- Transmitter Frequency (0018,9098)

- Resonant Nucleus (0018,9100)

- Spectral Width (0018,9052)

- Chemical Shift Reference (0018,9053)

- De-coupled Nucleus (0018,9060)

- De-coupling Frequency (0018,9061)

- De-coupling Chemical Shift Reference (0018,9063)

- Time Domain Filtering (0018,9065)

- Number of Zero Fills (0018,9066)

Value 1 shall contain the value corresponding to the sampling time axis (the axis along a data point row).

Value 2, if present, shall contain the value corresponding to the evolution time axis (the axis along a data point column).

##### C.8.14.1.2 MR Spectroscopy Zero Fill Explanation

Zero filling is a data processing technique where zero points are appended to the time domain data before Fourier transformation. The effect of zero filling is to increase the digital resolution in the spectrum. Since the zeros contain no new information, there is no new information added to the spectrum. It is artificially increasing the acquisition time after the data collection without adding any new information or true resolution to the spectrum. See Figure C.8.14.1-1, Figure C.8.14.1-2 and Figure C.8.14.1-3.

Figure C.8.14.1-1. Example Result without and with Zero Filling

Figure C.8.14.1-2. Echo Acquisition with Applying Zero Fill

Figure C.8.14.1-3. Free Induction Decay Acquisition with Applying Zero Fill

##### C.8.14.1.3 MR Spectroscopy Water Reference Data Clarification

MR Spectroscopy is using diagnostic data and water reference data. The water reference data is acquired and used to correct the phase of the diagnostic time domain data before the Fourier transformation to the frequency domain. The relation between the different spectroscopy objects is given in Figure C.8.14.1-4.

When Water Reference Acquisition (0018,9297) equals REFERENCED, it means that instances are available that were or can be used for Water Phase Correction. All other values mean that there are no instances available although data might have been used for water phase correction, see Water Referenced Phase Correction (0018,9199).

The water reference data can also be used for quantification of the signal strength of the diagnostic data.

Figure C.8.14.1-4. Relation Between Spectroscopy Instances

##### C.8.14.1.4 Water Reference Acquisition

The value of Water Reference Acquisition (0018,9297) specifies the intent of the spectroscopy data acquired.

Enumerated Values:

WATER_REFERENCE

  This instance is acquired to be used as water reference and can be used by other spectroscopy data in the study for water phase correction.

USED_DISCARDED

  The phase of this spectroscopic instance is corrected with water reference data. The water reference data used is discarded after correction and no longer available.

REFERENCED

  This spectroscopic instance has water reference data available for phase correction or the phase is already corrected with water reference data. The water reference data shall be specified in the Referenced Instance sequence (0008,114A).

NONE

  This spectroscopic instance has not been corrected for the water phase signal and water reference data has not been acquired.

#### C.8.14.2 MR Spectroscopy Pulse Sequence Module

The primary purpose of this module is to identify the pulse sequence and variations that were used in creation of the spectroscopic data. Terminology is intended to be neutral, and allow equivalent sequences provided by different vendors to be classified together.

Table C.8-103 specifies the attributes of the MR Spectroscopy Pulse Sequence Module.

Table C.8-103. MR Spectroscopy Pulse Sequence Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Pulse Sequence Name | (0018,9005) | 1C | Name of the pulse sequence for annotation purposes. Potentially vendor-specific name. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
MR Spectroscopy Acquisition Type | (0018,9200) | 1C | Identification of data encoding scheme. Defined Terms: SINGLE_VOXEL ROW PLANE VOLUME Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Echo Pulse Sequence | (0018,9008) | 1C | Echo category of pulse sequences. Enumerated Values: SPIN GRADIENT BOTH Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Multiple Spin Echo | (0018,9011) | 1C | Multiple Spin Echo category of pulse sequence used to collect different lines in k-space for a single frame. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and Echo Pulse Sequence (0018,9008) equals SPIN or BOTH. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and Echo Pulse Sequence (0018,9008) equals SPIN or BOTH.
Multi-planar Excitation | (0018,9012) | 1C | Technique that simultaneously excites several volumes. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Steady State Pulse Sequence | (0018,9017) | 1C | Steady State Sequence. Defined Terms: FREE_PRECESSION TRANSVERSE TIME_REVERSED LONGITUDINAL NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Echo Planar Pulse Sequence | (0018,9018) | 1C | Echo Planar category of pulse-sequences. Enumerated Values: YES NO Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Spectrally Selected Suppression | (0018,9025) | 1C | Spectrally Selected Suppression. Defined Terms: WATER FAT FAT_AND_WATER SILICON_GEL NONE Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Geometry of k-Space Traversal | (0018,9032) | 1C | Geometry category of k-Space traversal. Defined Terms: RECTILINEAR RADIAL SPIRAL Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Rectilinear Phase Encode Reordering | (0018,9034) | 1C | Rectilinear phase encode reordering. Defined Terms: LINEAR CENTRIC SEGMENTED REVERSE_LINEAR REVERSE_CENTRIC Required if Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and Geometry of k-Space Traversal (0018,9032) equals RECTILINEAR. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and Geometry of k-Space Traversal (0018,9032) equals RECTILINEAR.
Segmented k-Space Traversal | (0018,9033) | 1C | Segmented k-Space traversal. If Geometry of k-Space Traversal is rectilinear, multiple lines can be acquired at one time. If Geometry of k-Space Traversal is spiral or radial, paths can be interleaved and acquired at one time. Enumerated Values: SINGLE successive single echo coverage PARTIAL segmented coverage FULL single shot full coverage Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Coverage of k-Space | (0018,9094) | 1C | Coverage of k-Space. Defined Terms: FULL CYLINDRICAL ELLIPSOIDAL WEIGHTED Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED and MR Spectroscopy Acquisition Type (0018,9200) equals VOLUME. Otherwise may be present if Image Type (0008,0008) Value 1 is DERIVED and MR Spectroscopy Acquisition Type (0018,9200) equals VOLUME.
Number of k-Space Trajectories | (0018,9093) | 1C | Number of interleaves or shots. Required if Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.
Echo Peak Position | (0018,9298) | 3 | Number specifying the sample that coincides with the echo peak used during acquisition of the data. First sample will be numbered 1.

#### C.8.14.3 MR Spectroscopy Functional Group Macros

The following sections contain Functional Group Macro's specific to the MR Spectroscopy IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".".

##### C.8.14.3.1 MR Spectroscopy Frame Type Macro

Table C.8-104 specifies the attributes of the MR Spectroscopy Frame Type Functional Group Macro.

Table C.8-104. MR Spectroscopy Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Spectroscopy Frame Type Sequence | (0018,9227) | 1 | Identifies sequence containing Frame Type Attributes. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Spectroscopy data characteristics. See Section C.8.14.5.1.1.
>Include Table C.8-107 “MR Spectroscopy Description Macro Attributes” |

##### C.8.14.3.2 MR Spectroscopy FOV/Geometry Macro

Table C.8-105 specifies the attributes of the MR Spectroscopy FOV/Geometry Functional Group Macro.

Table C.8-105. MR Spectroscopy FOV/Geometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
MR Spectroscopy FOV/Geometry Sequence | (0018,9103) | 1 | Identifies the geometry parameters of this frame. Only a single Item shall be included in this sequence.
>Spectroscopy Acquisition Data Columns | (0018,9127) | 1C | Number of data points in the columns direction. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Spectroscopy Acquisition Phase Rows | (0018,9095) | 1C | Number of Phase Encoding Rows. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Spectroscopy Acquisition Phase Columns | (0018,9234) | 1C | Number of Phase Encoding Columns. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Spectroscopy Acquisition Out-of-plane Phase Steps | (0018,9159) | 1C | Number of out-of-plane Phase Encoding steps. Required if MR Spectroscopy Acquisition Type (0018,9200) equals PLANE and Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Percent Sampling | (0018,0093) | 1C | Fraction of acquisition matrix lines acquired, expressed as a percent. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Percent Phase Field of View | (0018,0094) | 1C | Ratio of field of view dimension in phase direction to field of view dimension in frequency direction, expressed as a percent. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

#### C.8.14.4 MR Spectroscopy Data Module

Table C.8-106 specifies the attributes that describe the Spectroscopy Data.

Table C.8-106. MR Spectroscopy Data Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Rows | (0028,0010) | 1 | Number of voxels in the vertical direction in the frame.
Columns | (0028,0011) | 1 | Number of voxels in the horizontal direction in the frame.
Data Point Rows | (0028,9001) | 1 | Number of rows of data points in spectroscopic data.
Data Point Columns | (0028,9002) | 1 | Number of columns of data points in spectroscopic data.
Data Representation | (0028,9108) | 1 | Data representation of the data points. Each data point shall have the same representation. Enumerated Values: COMPLEX Data is complex pair REAL Data contains only real component IMAGINARY Data contains only imaginary component MAGNITUDE Magnitude data
Signal Domain Columns | (0028,9003) | 1 | Domain of represented signal in column direction. Enumerated Values: FREQUENCY TIME
Signal Domain Rows | (0028,9235) | 1C | Domain of represented signal in row direction. Enumerated Values: FREQUENCY TIME Required if Data Point Rows (0028,9001) has a value of more than 1.
First Order Phase Correction Angle | (5600,0010) | 1C | First Order Phase Correction Angle. Number of values is determined by Row*Column*Number of Frames. Required if First Order Phase Correction (0018,9198) equals YES
Spectroscopy Data | (5600,0020) | 1 | A data stream of the signal intensities that comprise the spectroscopic data. See Section C.8.14.4.1 for further explanation.

##### C.8.14.4.1 Spectroscopy Data

The Spectroscopy Data attribute (5600,0020) contains the Signal intensities for the spectra. The order of voxels sent for each spectral plane is left to right, top to bottom, i.e., the upper left voxel (labeled 1,1) is sent first followed by the remainder of row 1, followed by the first voxel of row 2 (labeled 2,1) then the remainder of row 2 and so on. Each "voxel" represents an entire spectrum. The complete spectral data from each voxel is sent, followed by the spectral data from the next voxel position.

The number of voxels on each frame are described by Rows (0028,0010) and Columns (0028,0011). The number of frames is described by Number of Frames (0028,0008). The frames may represent different locations in a 3D acquisition, or the same position at a different point of time, or a difference of some other combination of attributes.

### Note

Either Rows or Columns or both may have a value of 1 (e.g., for single voxel spectroscopy). A value of zero for the corresponding value of Pixel Spacing in the Pixel Measures Macro is permitted under these circumstances. See Section 10.7.1.3.

The spectral data points are ordered from high frequencies to low frequencies for a fixed static magnetic field strength, in the case that the Signal Domain Columns (0028,9003) or Signal Domain Rows (0028,9235) attributes contain the value FREQUENCY.

The spectral data points are ordered in sequence of increasing time in the case that the Signal Domain Columns (0028,9003) or Signal Domain Rows (0028,9235) attributes contain the value TIME.

The apparent rotation of magnetization in a quadrature representation shall be counterclockwise (from the (positive) real part to the (positive) imaginary part) for positive relative frequencies.

### Note

When Complex time data points are transformed by a straightforward Fourier transformation to complex spectral data points, these are ordered from low frequency to high frequency.

For two-dimensional spectral acquisitions, the ordering is such that all data points from a row (corresponding to all data points acquired in an individual sampling period), are followed by all data points from the successive sampling period. Following all data of the rows from a given voxel position, the data from the subsequent voxel position are sent. The axis parallel to the row direction corresponds to the sampling time axis. The axis parallel to the column direction corresponds to the evolution time axis.

The dimensions of each spectrum that make up a voxel are described by Data Point Rows (0028,9001) and Data Point Columns (0028,9002). In the case of 1D spectra, the number of Data Point Rows shall be 1.

For a Data Representation (0028,9108) value of COMPLEX, the order of data points is real channel followed by imaginary channel for each spectral data point. For the other Data Representation values (REAL, IMAGINARY and MAGNITUDE), each spectral data point contains only a single value.

The Figure C.8-18 depicts 6 frames each made up of 4 rows and 4 columns of voxels. Specific values for Data Point Rows (0028,9001) and Data Point Columns (0028,9002) of these voxels are not depicted.

Figure C.8-18. Dimensions of Spectroscopy Data

#### C.8.14.5 MR Spectroscopy Description Macro

Table C.8-107 specifies the attributes that describe the Spectroscopy.

Table C.8-107. MR Spectroscopy Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Volumetric Properties | (0008,9206) | 1 | Indication if geometric manipulations are possible with frames in the SOP Instance. See Section C.8.14.5.1.2 for a description and Enumerated Values.
Volume Based Calculation Technique | (0008,9207) | 1 | Method used for volume calculations with frames in the SOP Instance. See Section C.8.14.5.1.3 for a description and Defined Terms.
Complex Image Component | (0008,9208) | 1 | Representation of complex data of frames in the SOP Instance. See Section C.8.14.5.1.4 for a description and Defined Terms.
Acquisition Contrast | (0008,9209) | 1 | Indication of acquisition contrast used with frames in the SOP Instance. See Section C.8.14.5.1.5 for a description and Defined Terms.

##### C.8.14.5.1 MR Spectroscopy Description Attribute Description

###### C.8.14.5.1.1 Image Type and Frame Type

Image Type (0008,0008) and Frame Type (0008,9007) are not included in this Macro but one or the other is always included in the Module or Macro that invokes this Macro, and they are therefore described here.

In addition to the requirements specified in Section C.8.16.1 Image Type and Frame Type, the following additional requirements and Defined Terms are specified.

###### C.8.14.5.1.1.1 Pixel Data Characteristics

See Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.14.5.1.1.2 Patient Examination Characteristics

See Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.14.5.1.1.3 Image Flavor

See Section C.8.16.1.3 for requirements, but not Defined Terms.

Table C.8-108 specifies the Defined Terms for MR Spectroscopy for Value 3 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-108. MR Spectroscopy Image Type and Frame Type Value 3

Defined Term Name | Defined Term Description
--- | ---
SPECTROSCOPY | Spectroscopy

###### C.8.14.5.1.1.4 Derived Pixel Contrast

See Section C.8.16.1.4 for requirements, but not Defined Terms.

Table C.8-109 specifies the Defined Terms for Value 4 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-109. MR Spectroscopy Image Type and Frame Type Value 4

Defined Term Name | Defined Term Description
--- | ---
ADDITION | Created through point by point addition operation
DIVISION | Created through point by point division operation
MAXIMUM | Created through point by point maximum operation
MEAN | Created through point by point mean operation
MINIMUM | Created through point by point minimum operation
MULTIPLICATION | Created through point by point multiplication operation
STD_DEVIATION | Standard Deviation
SUBTRACTION | Created through point by point subtraction operation
NONE | Not calculated
MIXED | Used only as value in Image Type (0008,0008) if frames within the spectroscopy SOP Instance contain different values for value 4 in their Frame Type (0008,9007) attribute.

###### C.8.14.5.1.2 Volumetric Properties

See Section C.8.16.2.1.2. No additional requirements or Defined Terms.

###### C.8.14.5.1.3 Volume Based Calculation Technique Attribute

See Section C.8.16.2.1.3 for requirements, but not Defined Terms.

Table C.8-110 specifies the Defined Terms for the Volume Based Calculation Technique (0008,9207) attribute.

Table C.8-110. Volume Based Calculation Technique Attribute Values

Defined Term Name | Defined Term Description
--- | ---
MAX_IP | Maximum Intensity Projection
MIN_IP | Minimum Intensity Projection
NONE | Pixels not derived geometrically
MIXED | Used only as a value in Volume Based Calculation Technique (0008,9207) attribute in the MR Spectroscopy Module if frames within the image SOP Instance contain different terms for the Volume Based Calculation Technique attribute in MR Spectroscopy Frame Type Functional Group.

###### C.8.14.5.1.4 Complex Image Component

The value of Complex Image Component attribute (0008,9208) shall be used to indicate which component of the complex representation of the signal is represented in the spectroscopy data.

Table C.8-111 specifies the Defined Terms for Complex Image Component (0008,9208).

Table C.8-111. Complex Image Component Attribute Values

Defined Term Name | Defined Term Description
--- | ---
MAGNITUDE | The magnitude component of the complex spectroscopy data.
PHASE | The phase component of the complex spectroscopy data.
REAL | The real component of the complex spectroscopy data.
IMAGINARY | The imaginary component of the complex spectroscopy data.
COMPLEX | The real and imaginary components of the complex spectroscopy data
MIXED | Used only as a value in Complex Image Component (0008,9208) in the MR Spectroscopy Module if frames within the image SOP Instance contain different values for the Complex Image Component attribute in the MR Spectroscopy Frame Type Functional Group.

###### C.8.14.5.1.5 Acquisition Contrast

Table C.8-112 specifies the Defined Terms for Acquisition Contrast (0008,9209).

Table C.8-112. Acquisition Contrast Values

Defined Term Name | Defined Term Description
--- | ---
PROTON_DENSITY | Proton Density weighted contrast
T1 | T1 weighted contrast
T2 | T2 weighted contrast
UNKNOWN | Value should be UNKNOWN if acquisition contrasts were combined resulting in an unknown contrast. Also this value should be used when the contrast is not known.
MIXED | Used only as a value in Acquisition Contrast (0008,9209) attribute in the MR Spectroscopy Module if frames within the SOP Instance contain different values for the Acquisition Contrast attribute in the MR Spectroscopy Frame Type Functional Group.

### C.8.15 Enhanced CT Image

This section describes the specific modules for the Enhanced CT Image IOD.

#### C.8.15.1 CT Series Module

The CT IODs use the General Series module described in Section C.7.3.1, specialized by the CT Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of CT device.

Table C.8-113 specifies the Attributes that identify and describe general information about the CT Series.

Table C.8-113. CT Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: CT See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.15.2 Enhanced CT Image Module

This section describes the Enhanced CT Image Module. Table C.8-114 specifies the attributes of the Enhanced CT Image Module.

Table C.8-114. Enhanced CT Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image characteristics. See Section C.8.16.1 and Section C.8.15.2.1.1.
Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
Acquisition Number | (0020,0012) | 3 | A number identifying the single continuous gathering of data over a period of time that resulted in this image. ### Note This number is not required to be unique across SOP Instances in a series. See also the description of the Referenced Raw Data Sequence (0008,9121).
Acquisition DateTime | (0008,002A) | 1C | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800). See Section C.7.6.16.2.2.1 for an overview of all acquisition related timing attributes. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted), may be present otherwise.
Acquisition Duration | (0018,9073) | 1C | The time in seconds needed to complete the acquisition of data. See Section C.7.6.16.2.2.1 for further explanation. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL or MIXED and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted), may be present otherwise.
Referenced Raw Data Sequence | (0008,9121) | 3 | The Raw data that was used to derive this Image. One or more Items are permitted in this Sequence. ### Note The items of in this sequence may identify raw data that has not been stored or encoded as a DICOM object. This allows recognition that images in different instances have been reconstructed from the same raw data.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Waveform Sequence | (0008,113A) | 3 | References to waveforms acquired in conjunction with this image. These Waveforms may or may not be temporally synchronized with this image. One or more Items are permitted in this sequence.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Image Evidence Sequence | (0008,9092) | 1C | Full set of Composite SOP Instances referring to image SOP Instances inside the frames of this Enhanced CT Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Source Image Evidence Sequence | (0008,9154) | 1C | Full set of Composite SOP Instances used as source image SOP Instances inside the frames of this Enhanced CT Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Source Image Sequence (0008,2112) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Presentation State Sequence | (0008,9237) | 1C | References to Presentation State instances acquired in conjunction with this instance. ### Note May only be used to reference Presentation States belonging to the acquired data and not to reference Presentation States generated subsequently such as during interpretation. One or more Items shall be included in this sequence. Required if Presentation State is generated during acquisition, shall not be present otherwise.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. This value shall be 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME2 See Section C.7.6.3.1.2 for definition of this term.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. This value shall be 16.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. This value shall be 12 or16.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Content Qualification | (0018,9004) | 1C | Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See Section C.8.13.2.1.1 for further explanation. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted), may be present otherwise.
Image Comments | (0020,4000) | 3 | User-defined comments about the image
Burned In Annotation | (0028,0301) | 1C | Indicates whether or not the image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO This means that images that contain this Module shall not contain such burned in annotations. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted), may be present otherwise.
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted). May be present otherwise.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1 | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this Sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6.
Include Table 10-25 “Optional View and Slice Progression Direction Attributes” |
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.
Include Table 10-27 “RT Equipment Correlation Macro Attributes Description”

##### C.8.15.2.1 CT Image Description Attribute Description

###### C.8.15.2.1.1 Image Type and Frame Type

In addition to the requirements specified in Section C.8.16.1 Image Type and Frame Type, the following additional requirements and Defined Terms are specified.

These requirements and Defined Terms are also applicable to Frame Type (0008,9007).

###### C.8.15.2.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.15.2.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.15.2.1.1.3 Image Flavor

Table C.8-115 specifies the Defined Terms for CT additional to those defined in Section C.8.16.1.3 for Value 3 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-115. Image Type and Frame Type Value 3 for CT

Defined Term Name | Defined Term Description
--- | ---
ATTENUATION | Collected for the purpose of performing attenuation corrections (e.g., PET attenuation correction)
CARDIAC_CTA | Images of the heart collected for the purpose of CT Coronary Angiography (CTA)
CARDIAC_CASCORE | Images of the heart collected for the purpose of CT Coronary Calcium Scoring
REFERENCE | Collected for anatomical reference for PET or SPECT

###### C.8.15.2.1.1.4 Derived Pixel Contrast

Table C.8-116 specifies the Defined Terms for CT additional to those defined in Section C.8.16.1.4 for Value 4 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8-116. Image Type and Frame Type Value 4 for Ct

Defined Term Name | Defined Term Description
--- | ---
FILTERED | An image filter has been applied
MEDIAN | Pixel by pixel median
ENERGY_PROP_WT | Image pixels created through proportional weighting of multiple acquisitions at distinct X-Ray energies.

#### C.8.15.3 Enhanced CT Image Functional Group Macros

The following sections contain Functional Group Macros specific to the Enhanced CT Image IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".

##### C.8.15.3.1 CT Image Frame Type Macro

Table C.8-117 specifies the attributes of the CT Image Frame Type Functional Group Macro.

Table C.8-117. CT Image Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Image Frame Type Sequence | (0018,9329) | 1 | Identifies the characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008), except that the value MIXED is not allowed unless the SOP Class UID is "1.2.840.10008.5.1.4.1.1.2.2" (Legacy Converted). See Section C.8.16.1 and Section C.8.15.2.1.1.1.
>Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |

##### C.8.15.3.2 CT Acquisition Type Macro

Table C.8-118 specifies the attributes of the CT Acquisition Type Functional Group Macro.

Table C.8-118. CT Acquisition Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Acquisition Type Sequence | (0018,9301) | 1 | Contains the attributes defining the CT acquisition mode. Only a single Item shall be included in this sequence.
>Acquisition Type | (0018,9302) | 1C | Description of the method used during acquisition of this frame. See Section C.8.15.3.2.1 for Defined Terms. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Tube Angle | (0018,9303) | 1C | The constant angle at which the x-ray source is located during acquisition. 0 degrees means that the source is located at the highest point of the gantry orbit. Degrees increase from 0 to positive 360 in a clockwise direction as viewed when facing the gantry where the table enters the gantry. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is CONSTANT_ANGLE. May be present otherwise if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is CONSTANT_ANGLE.
>Constant Volume Flag | (0018,9333) | 1C | Identifies that the acquisition was performed by repetitively acquiring the same volume set over a period of time. ### Note Acquisition Type (0018,9302) may be SEQUENCED, SPIRAL or STATIONARY depending on whether table movement is necessary to cover the volume. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Fluoroscopy Flag | (0018,9334) | 1C | Identifies that near real-time display of a block of continuously acquired data was performed, which may result in a lower than usual image quality. Enumerated Values: YES NO Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

###### C.8.15.3.2.1 Acquisition Type

Defined Terms:

SEQUENCED

  identifies that the acquisition was performed by acquiring single or multi detector data while rotating the source about the gantry while the table is not moving; additional slices may be acquired by incrementing the table position and again rotating the source about the gantry while the table is not moving

SPIRAL

  identifies that the acquisition was performed by acquiring data while rotating the source about the gantry while continuously moving the table

CONSTANT_ANGLE

  identifies that the acquisition was performed by holding the source at a constant angle and moving the table to obtain a projection image (e.g., a localizer image)

STATIONARY

  identifies that the acquisition was performed by holding the table at a constant position and performing one or more acquisitionsover time at the same location

FREE

  identifies that the acquisition was performed while rotating the source about the gantry while the table movement is under direct control of a human operator or under the control of an analysis application (e.g., fluoroscopic image)

##### C.8.15.3.3 CT Acquisition Details Macro

Table C.8-119 specifies the attributes of the CT Acquisition Details Functional Group Macro.

Table C.8-119. CT Acquisition Details Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Acquisition Details Sequence | (0018,9304) | 1 | Contains the attributes defining the details of the acquisition. Only a single Item shall be included in this sequence.
>Rotation Direction | (0018,1140) | 1C | Direction of rotation of the source about the gantry, as viewed while facing the gantry where the table enters the gantry. Enumerated Values: CW clockwise CC counter clockwise Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is other than CONSTANT_ANGLE. Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is other than CONSTANT_ANGLE.
>Revolution Time | (0018,9305) | 1C | The time in seconds of a complete revolution of the source around the gantry orbit. This value is independent of the Reconstruction Angle (0018,9319) of the frame. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is other than CONSTANT_ANGLE. Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is other than CONSTANT_ANGLE.
>Single Collimation Width | (0018,9306) | 1C | The width of a single row of acquired data (in mm). ### Note Adjacent physical detector rows may have been combined to form a single effective acquisition row. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Total Collimation Width | (0018,9307) | 1C | The width of the total collimation (in mm) over the area of active x-ray detection. ### Note This will be equal to the number of effective detector rows multiplied by single collimation width. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Table Height | (0018,1130) | 1C | The distance in mm from the top of the patient table to the center of rotation of the source (i.e., the data collection center or isocenter). The distance is positive when the table is below the data collection center. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Gantry/Detector Tilt | (0018,1120) | 1C | Nominal angle of tilt in degrees of the scanning gantry. Not intended for mathematical computations. Zero degrees means the gantry is not tilted, negative degrees are when the top of the gantry is tilted away from where the table enters the gantry. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Data Collection Diameter | (0018,0090) | 1C | The diameter in mm of the region over which data were collected. See Section C.8.15.3.6.1. ### Note In the case of an Acquisition Type (0018,9302) of CONSTANT_ANGLE, the diameter is that in a plane normal to the central ray of the diverging X-Ray beam as it passes through the data collection center. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

##### C.8.15.3.4 CT Table Dynamics Macro

Table C.8-120 specifies the attributes of the CT Table Dynamics Functional Group Macro.

Table C.8-120. CT Table Dynamics Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Table Dynamics Sequence | (0018,9308) | 1 | Contains the attributes defining the movement of the CT table. Only a single Item shall be included in this sequence.
>Table Speed | (0018,9309) | 1C | The distance in mm that the table moves in one second during the gathering of data that resulted in this frame. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is SPIRAL or CONSTANT_ANGLE. May be present otherwise if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is SPIRAL or CONSTANT_ANGLE.
>Table Feed per Rotation | (0018,9310) | 1C | Motion of the table (in mm) during a complete revolution of the source around the gantry orbit. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is SPIRAL. May be present otherwise if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is SPIRAL.
>Spiral Pitch Factor | (0018,9311) | 1C | Ratio of the Table Feed per Rotation (0018,9310) to the Total Collimation Width (0018,9307). See Section C.8.15.3.4.1 for further explanation and some examples. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Acquisition Type (0018,9302) is SPIRAL. May be present otherwise if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Acquisition Type (0018,9302) is SPIRAL.

###### C.8.15.3.4.1 Spiral Pitch Factor

The formula for Spiral Pitch Factor (0018,9311) in terms of Table Feed per Rotation (0018,9310) and Total Collimation Width (0018,9307) is:

Spiral Pitch Factor = (Table Feed per Rotation (mm))/(Total Collimation Width (mm))

An example calculation of Spiral Pitch Factor (0018,9311) for a single slice spiral acquisition of an image with a Total Collimation Width of 2.5mm and a Table Feed per Rotation of 10mm is:

Spiral Pitch Factor = (10 mm) / (2.5 mm) = 4.0

An example calculation of Spiral Pitch Factor (0018,9311) for a multiple slice spiral acquisition having a Total Collimation Width of 20mm and a Table Feed per Rotation of 10mm is:

Spiral Pitch Factor = (10 mm) / (20 mm) = 0.5

##### C.8.15.3.5 CT Position Macro

Table C.8-121 specifies the attributes of the CT Position Functional Group Macro.

Table C.8-121. CT Position Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Position Sequence | (0018,9326) | 1 | Contains the attributes defining the CT geometry. Only a single Item shall be included in this sequence.
>Table Position | (0018,9327) | 1C | Relative longitudinal position of acquisition location of this frame in mm from an implementation specific reference point. Shall be relative to the same reference point for all frames in this SOP Instance, but may be different from the reference point in other SOP Instances. Positions as the table moves into the gantry viewed from the front are more negative. ### Note For contiguous slices reconstructed from multiple detectors one would expect different values for adjacent slices. Lateral positioning or tilting or swiveling are not described. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Data Collection Center (Patient) | (0018,9313) | 1C | The x, y, and z coordinates (in the patient coordinate system) in mm of the center of the region in which data were collected. See Section C.8.15.3.6.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Reconstruction Target Center (Patient) | (0018,9318) | 1C | The x, y, and z coordinates (in the patient coordinate system) of the reconstruction center target point as used for reconstruction in mm. See Section C.8.15.3.6.1. ### Note If the reconstructed image is not magnified or panned the value corresponds with the Data Collection Center (0018,9313) attribute. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

##### C.8.15.3.6 CT Geometry Macro

Table C.8-122 specifies the attributes of the CT Geometry Functional Group Macro.

Table C.8-122. CT Geometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Geometry Sequence | (0018,9312) | 1 | Contains the attributes defining the CT geometry. Only a single Item shall be included in this sequence.
>Distance Source to Detector | (0018,1110) | 1C | Distance in mm from source to detector center. See Section C.8.15.3.6.1. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID). Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Distance Source to Data Collection Center | (0018,9335) | 1C | Distance in mm from source to data collection center. See Section C.8.15.3.6.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

###### C.8.15.3.6.1 Relationships Between CT Geometric Attributes (Informative)

In Figure C.8-19 the relationship of the Geometric Attributes within the CT Geometry and CT Reconstruction functional groups is shown. Figure C.8-19, viewed from the front of the gantry (where the table enters the gantry), is informative only and is not meant to represent a standardization of an equipment-based frame of reference.

Figure C.8-19. Geometry of CT Acquisition System

##### C.8.15.3.7 CT Reconstruction Macro

Table C.8-123 specifies the attributes of the CT Reconstruction Functional Group Macro.

Table C.8-123. CT Reconstruction Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Reconstruction Sequence | (0018,9314) | 1 | Contains the attributes holding information about the reconstruction techniques used. Only a single Item shall be included in this sequence.
>Reconstruction Algorithm | (0018,9315) | 1C | Description of the algorithm used when reconstructing the image from the data acquired during the acquisition process. Defined Terms: FILTER_BACK_PROJ ITERATIVE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Convolution Kernel | (0018,1210) | 1C | A label describing the convolution kernel or algorithm used to reconstruct the data. A single value shall be present. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Convolution Kernel Group | (0018,9316) | 1C | A label describing the group to which Convolution Kernel (0018,1210). Defined Terms: BRAIN SOFT_TISSUE LUNG BONE CONSTANT_ANGLE Required if Convolution Kernel (0018,1210) is present. May be present otherwise.
>Reconstruction Diameter | (0018,1100) | 1C | The diameter in mm of the region from which data were used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region. See Section C.8.15.3.6.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Reconstruction Field of View (0018,9317) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Reconstruction Field of View (0018,9317) is not present.
>Reconstruction Field of View | (0018,9317) | 1C | The field of view width (x-dimension) followed by height (y-dimension) as used for reconstruction in mm. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Reconstruction Diameter (0018,1100) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Reconstruction Diameter (0018,1100) is not present.
>Reconstruction Pixel Spacing | (0018,9322) | 1C | Physical distance in the patient between the center of each reconstructed pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Reconstruction Angle | (0018,9319) | 1C | Angle (in degrees) over which the data from which the frame was reconstructed was collected, where 360 degrees signifies a complete revolution of the source around the gantry orbit. It is possible, in the case of over-scanning that the Reconstruction Angle is greater than 360 degrees. Shall be 0 if Acquisition Type (0018,9302) is CONSTANT_ANGLE. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Image Filter | (0018,9320) | 1C | A label describing the filter applied to the reconstructed image after the original reconstruction has been completed. ### Note When Frame Type (0008,9007) Value 1 of this frame is DERIVED and Frame Type (0008,9007) Value 4 is FILTERED the type of filtration is described in Derivation Image Macro. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL.

##### C.8.15.3.8 CT Exposure Macro

Table C.8-124 specifies the attributes of the CT Exposure Functional Group Macro.

Table C.8-124. CT Exposure Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Exposure Sequence | (0018,9321) | 1 | Contains the attributes defining exposure information. Only a single Item shall be included in this sequence.
>Exposure Time in ms | (0018,9328) | 1C | Duration of exposure for this frame in milliseconds. If Acquisition Type (0018,9302) equals SPIRAL the duration of the exposure time for this frame shall be Revolution Time (0018,9305) divided by the Spiral Pitch Factor (0018,9311). See Section C.8.15.3.8.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>X-Ray Tube Current in mA | (0018,9330) | 1C | Nominal X-Ray tube current in milliamperes. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Exposure in mAs | (0018,9332) | 1C | The exposure expressed in milliampere seconds, for example calculated from exposure time and X-Ray tube current. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Exposure Modulation Type | (0018,9323) | 1C | A label describing the type of exposure modulation used for the purpose of limiting the dose. Defined Terms: NONE Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Estimated Dose Saving | (0018,9324) | 2C | A percent value of dose saving due to the use of Exposure Modulation Type (0018,9323). A negative percent value of dose savings reflects an increase of exposure. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Exposure Modulation Type (0018,9323) is not equal to NONE. Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Exposure Modulation Type (0018,9323) is not equal to NONE.
>CTDIvol | (0018,9345) | 2C | Computed Tomography Dose Index (CTDIvol), in mGy according to IEC 60601-2-44, Ed.2.1 (Clause 29.1.103.4), The Volume CTDIvol. It describes the average dose for this frame for the selected CT conditions of operation. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>CTDI Phantom Type Code Sequence | (0018,9346) | 3 | The type of phantom used for CTDI measurement according to IEC 60601-2-44. Only a single Item is permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4052 “Phantom Devices”.

### Note

The dose that a patient receives in a given procedure may be reported in one or more instances of the Radiation Dose Report SOP Class using TID 10011 “CT Radiation Dose”.

###### C.8.15.3.8.1 Exposure Time in ms Attribute (Informative)

An example of how the value of Exposure Time in ms (0018,9328) can be calculated:

The Exposure Time Texposuretime of a volume shall be the time of the X-Ray radiation in position with this volume. It depends on the travel speed and the total collimation width.

Texposuretime of the volume represented by a distinguished frame of a Spiral Scan can be calculated as follows:

Texposuretime = N x S / Vtravelspeed

CTpitchfactor = DD / N x S

Vtravelspeed = DD / Trevolutiontime

From this the exposure time can be derived:

Texposuretime = N x S x Trevolutiontime / DD = Trevolutiontime / CTpitchfactor

Legend:

DD = Table Feed per Rotation (0018,9310) in mm distance moved by the patient support in the z direction per 360° revolution in Spiral scanning

S = collimation of a single slice in mm

N = number slices

N x S = Total Collimation Width (0018,9307) in mm

Vtravelspeed = Table Speed (0018,9309) in mm/second, travel speed of the patient table

Trevolutiontime = Revolution time (0018,9305) in seconds

CTpitchfactor = Spiral Pitch Factor (0018,9311)

##### C.8.15.3.9 CT X-Ray Details Macro

Table C.8-125 specifies the attributes of the CT X-Ray Details Functional Group Macro.

Table C.8-125. CT X-Ray Details Sequence Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT X-Ray Details Sequence | (0018,9325) | 1 | Contains the attributes defining the x-ray information. Only a single Item shall be included in this sequence.
>KVP | (0018,0060) | 1C | Peak kilo voltage output of the x-ray generator used. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Focal Spot(s) | (0018,1190) | 1C | Used nominal size of the focal spot in mm. The attribute may only have one or two values, for devices with variable focal spot, small dimension followed by large dimension Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Filter Type | (0018,1160) | 1C | Type of filter(s) inserted into the X-Ray beam. Defined Terms: WEDGE BUTTERFLY MULTIPLE FLAT SHAPED NONE ### Note Multiple type of filters can be expressed by a combination, e.g., BUTTERFLY+WEDGE. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Filter Material | (0018,7050) | 1C | The X-Ray absorbing material used in the filter. May be multi-valued. Defined Terms: MOLYBDENUM ALUMINUM COPPER RHODIUM NIOBIUM EUROPIUM LEAD MIXED ### Note MIXED may be used to indicate a filter type of complex composition for which listing the individual materials would be excessive or undesirable; it is not intended to mean "unknown". Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and the value of Filter Type (0018,1160) is other than NONE. May be present otherwise.
>Calcium Scoring Mass Factor Patient | (0018,9351) | 3 | The calibration factor for the calcium mass score. These factors incorporate the effects of KV value of the CT image the patient size. machine specific corrections See Section C.8.2.1.1.7.
>Calcium Scoring Mass Factor Device | (0018,9352) | 3 | The calibration factors for the calcium mass score of the device. These factors incorporate the effects of KV value of the CT image machine specific corrections This a multi-value attribute, the first value specifies the mass factor for a small patient size, the second value for a medium patient size and the third value for a large patient size. See Section C.8.2.1.1.7.
>Energy Weighting Factor | (0018,9353) | 1C | The weighting factor of the data from the primary source in a multiple energy composition image. This factor incorporates the effects of the specific X-Ray source and kV value examination specific characteristics. Required if Required if Frame Type (0008,9007) Value 4 of this frame is ENERGY_PROP_WT. May be present otherwise.

##### C.8.15.3.10 CT Pixel Value Transformation Macro

Table C.8-126 specifies the attributes of the CT Pixel Value Transformation Functional Group Macro.

### Note

1. This Macro is equivalent to the Modality LUT transformation in non Multi-frame IODs.

2. This in effect specializes the Section C.7.6.16.2.9 Pixel Value Transformation Macro.

Table C.8-126. CT Pixel Value Transformation Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Pixel Value Transformation Sequence | (0028,9145) | 1 | Contains the attributes involved in the transformation of stored pixel values. Only a single Item shall be included in this sequence.
>Rescale Intercept | (0028,1052) | 1 | The value b in relationship between stored values (SV) and the output units. Output units = m*SV + b.
>Rescale Slope | (0028,1053) | 1 | m in the equation specified by Rescale Intercept (0028,1052).
>Rescale Type | (0028,1054) | 1 | Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). See Section C.11.1.1.2 for further explanation. If Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Frame Type (0008,9007) Value 3 is not LOCALIZER, the value shall be HU (Hounsfield Units).

##### C.8.15.3.11 CT Additional X-Ray Source Macro

Table C.8-126b specifies the attributes of the CT Additional X-Ray Source Macro. This sequence may be multi-valued, depending on the number of additional active X-Ray sources. It defines the X-Ray source parameters beyond the basic system.

Table C.8-126b. CT Additional X-Ray Source Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
CT Additional X-Ray Source Sequence | (0018,9360) | 1 | Contains the attributes defining the data acquisition in a multiple X-Ray source system beyond the primary source. The primary X-Ray source is specified in the CT X-Ray Details Sequence. One or more Items shall be included in this sequence.
>KVP | (0018,0060) | 1 | Peak kilo voltage output of the X-Ray generator used.
>X-Ray Tube Current in mA | (0018,9330) | 1 | Nominal X-Ray tube current in milliamperes.
>Data Collection Diameter | (0018,0090) | 1 | The diameter in mm of the region over which data were collected.
>Focal Spot(s) | (0018,1190) | 1 | Used nominal size of the focal spot in mm.
>Filter Type | (0018,1160) | 1 | Type of filter(s) inserted into the X-Ray beam. See Section C.8.15.3.9.
>Filter Material | (0018,7050) | 1 | The X-Ray absorbing material used in the filter.
>Exposure in mAs | (0018,9332) | 1 | The exposure expressed in milliampere seconds, for example calculated from exposure time and X-Ray tube current.
>Energy Weighting Factor | (0018,9353) | 1C | The weighting factor of the data from this additional source in a multiple energy composition image. This factor incorporates the effects of the specific X-Ray source and kV value examination specific characteristics. Required if Required if Frame Type (0008,9007) Value 4 of this frame is ENERGY_PROP_WT. May be present otherwise.

### C.8.16 Common CT and MR Descriptions

This section contains descriptions of Macros and Attributes used in Modules and Functional Group Macros that are common to the Enhanced CT Image, Enhanced MR Images and MR Spectroscopy IODs.

#### C.8.16.1 Image Type and Frame Type

Image Type (0008,0008) and associated Image Type related attributes provide a high level description of a multi-frame SOP Instance. These attributes describe properties that provide key summary information to users of the SOP Instance. Image Type (0008,0008) contains the highest level summary of what is in the SOP Instance.

Frame Type (0008,9007) mirrors the corresponding Image Type attribute and applies to the frame level rather than to the image level.

If more than one value is used by the set of frames for a given Frame Type (0008,9007) attribute value or associated attribute value then the corresponding value of Image Type (0008,0008) or associated attribute shall contain a value of MIXED. This indicates that a mixed set of values exists within the multi-frame SOP Instance.

The value MIXED shall only be used in Image Type (0008,0008) when the corresponding values for the individual frames are not equal. When a value of an attribute is equal for all frames, the same value shall be used for the corresponding value of Image Type (0008,0008). Values 2 and 3 of Image Type (0008,0008) are an exception to the rule for MIXED: Values 2 and 3 may never have the value of MIXED as described in Section C.8.16.1.2 and Section C.8.16.1.3.

Image Type (0008,0008) and Frame Type (0008,9007) shall consist of four non-zero length values.

##### C.8.16.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) shall use one of the following Enumerated Values from Table C.8-127.

Value 1 of Image Type (0008,0008) and Value 1 of Frame Type (0008,9007) shall not be zero length.

Table C.8-127. Image Type and Frame Type Value 1

Enumerated Value Name | Enumerated Value Description
--- | ---
ORIGINAL | An image or frame is original if its pixel data was directly reconstructed from the original data that is obtained from the sensors of the imaging equipment, Image Type (0008,0008) Value 4 is NONE, and Volume Based Calculation Technique (0008,9207) is NONE. ### Note For MR, original data is data directly reconstructed from k-space data. For CT, original frames are those directly reconstructed from projection data.
DERIVED | An image or frame is derived if its pixel data was calculated from original or other derived pixel data (i.e., it is not original).
MIXED | Used only as a value in Image Type (0008,0008) if frames within the SOP Instance contain different values for Value 1 in their Frame Type (0008,9007).

##### C.8.16.1.2 Patient Examination Characteristics

Value 2 for Image Type (0008,0008) and Frame Type (0008,9007) follows the standard definition and shall have the following Enumerated Value from Table C.8-128.

Value 2 of Image Type (0008,0008) and Value 2 of Frame Type (0008,9007) shall not be zero length.

Table C.8-128. Image Type and Frame Type Value 2

Enumerated Value Name | Enumerated Value Description
--- | ---
PRIMARY | See Section C.7.6.1.1.2

##### C.8.16.1.3 Image Flavor

Value 3 is an overall representation of the image type. This value may be a summary of several other attributes or a duplication of one of the other attributes to indicate the most important aspect of this image. Value 3 Image Flavor is to be used with Value 4 Derived Pixel Contrast to indicate the nature of the image set.

### Note

For example Value 3 = DIFFUSION together with Value 4 = NONE indicates that the image set was originally collected for DIFFUSION.

If Value 3 = DIFFUSION together with Value 4 = DIFFUSION this indicates that the object contains DIFFUSION weighted post processed images.

Value 3 of Image Type (0008,0008) shall not be zero length.

Value 3 of Frame Type (0008,9007) may have the same value as found in Value 3 of Image Type (0008,0008), or may have a different value or may be of zero length.

The attribute value may not be MIXED as this value needs to be a summary of the primary purpose of the images, whether the frames have the same value or not.

Table C.8-129 specifies the Defined Terms for Value 3 for Image Type (0008,0008) and Frame Type (0008,9007) that are common to CT and MR. Additional Defined Terms are defined in the modality-specific Module and Macro definitions.

Table C.8-129. Image Type and Frame Type Value 3 Common

Defined Term Name | Defined Term Description
--- | ---
ANGIO | Collected for the purpose of angiography
CARDIAC | Images of the heart
CARDIAC_GATED | Cardiac gated images, other than of the heart
CARDRESP_GATED | Cardiac and respiratory gated images
DYNAMIC | An image in which the same anatomical volume is imaged at multiple times in order to capture images of a non-cyclic, time varying event. For example, imaging of the uptake of a tracer or contrast in a specific organ over time. ### Note This is different from gating techniques, in which the same anatomical volume is imaged during some portion of a cyclic event, e.g., inspiration or R-R Interval.
FLUOROSCOPY | Real-time collection of single slices (e.g., CT or MR Fluoroscopy)
LOCALIZER | Collected for the purpose of planning other images.
MOTION | Collected for looking at body motion
PERFUSION | Collected for the purposes of perfusion calculations.
PRE_CONTRAST | Collected before contrast was administered
POST_CONTRAST | Collected during or after contrast was administered
RESP_GATED | Respiratory gated images
REST | Cardiac rest image set
STATIC | A group of frames at varying spatial locations acquired at the same time.
STRESS | Cardiac stress image set
VOLUME | Set of frames that define a regularly sampled volume
NON_PARALLEL | Set of frames that are not parallel
PARALLEL | Set of frames that are parallel but do not constitute a regularly sampled volume
WHOLE_BODY | A group of frames of the whole body; the frames may be acquired at various times (as distinct from STATIC).

##### C.8.16.1.4 Derived Pixel Contrast

Value 4 shall be used to indicate derived pixel contrast - generally, contrast created by combining or processing images with the same geometry. Value 4 shall have a value of NONE when Value 1 is ORIGINAL.

### Note

If more than one of the following derived types is applicable, then it is up to the generating application to specify the value that best characterizes the derived image.

Value 4 of Image Type (0008,0008) and Value 4 of Frame Type (0008,9007) shall not be zero length unless the SOP Class UID is "1.2.840.10008.5.1.4.1.1.2.2" or "1.2.840.10008.5.1.4.1.1.4.4" or "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted).

Table C.8-130 specifies the Defined Terms for Value 4 for Image Type (0008,0008) and Frame Type (0008,9007) that are common to CT and MR. Additional Defined Terms are defined in the modality-specific Module and Macro definitions.

Table C.8-130. Image Type and Frame Type Value 4 Common

Defined Term Name | Defined Term Description
--- | ---
ADDITION | Created through Pixel by pixel addition operation
DIVISION | Created through Pixel by pixel division operation
MASKED | Created through Pixel by pixel masking operation
MAXIMUM | Created through Pixel by Pixel Maximum operation
MEAN | Created through Pixel by pixel mean operation
MINIMUM | Created through Pixel by Pixel Minimum operation
MTT | Mean Transit Time
MULTIPLICATION | Created through Pixel by pixel multiplication operation
RCBF | Regional Cerebral Blood Flow (rCBF)
RCBV | Regional Cerebral Blood Volume (rCBV)
RESAMPLED | Pixels have been spatially re-sampled, e.g., MPR
STD_DEVIATION | Standard Deviation
SUBTRACTION | Created through Pixel by pixel subtraction operation
T_TEST | Student's T-Test
TTP | Time To Peak map
Z_SCORE | Z-Score Map
NONE | Not a calculated image
MIXED | Used only as value in Image Type (0008,0008) if frames within the image SOP Instance contain different values for value 4 in their Frame Type (0008,9007) attribute.

#### C.8.16.2 Common CT/MR Image Description Macro

This section describes the Common CT/MR Image Description Macro.

Table C.8-131 specifies the attributes of the Common CT/MR Image Description Macro.

Table C.8-131. Common CT/MR Image Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Pixel Presentation | (0008,9205) | 1 | Indication of the presence or absence of color information that may be used during rendering. See Section C.8.16.2.1.1 for a description and Enumerated Values.
Volumetric Properties | (0008,9206) | 1 | Indication if geometric manipulations are possible with frames in the SOP Instance. See Section C.8.16.2.1.2 for a description and Enumerated Values.
Volume Based Calculation Technique | (0008,9207) | 1 | Method used for volume calculations with frames in the SOP Instance. See Section C.8.16.2.1.3 for a description and Defined Terms.

##### C.8.16.2.1 Common CT/MR Image Description Attribute Description

###### C.8.16.2.1.1 Pixel Presentation

Table C.8-132. Pixel Presentation Attribute Values

Enumerated Value Name | Enumerated Value Description
--- | ---
COLOR | Image is best displayed in color using Supplemental Palette Color LUTs, but can be displayed in grayscale if current display does not support color. See Section C.8.16.2.1.1.1.
MONOCHROME | Image is intended to be displayed in grayscale only. No Supplemental Palette Color LUTs are supplied.
MIXED | Used only as a value in Pixel Presentation (0008,9205) in the Enhanced MR Image Module or Enhanced CT Image Module if frames within the image SOP Instance contain different values for the Pixel Presentation attribute in the MR Image Frame Type Functional Group or CT Image Frame Type Functional Group.
TRUE_COLOR | Image can be displayed in color only

###### C.8.16.2.1.1.1 Supplemental Palette Color LUTs

Figure C.8-20 presents two separate image visualization pipelines that can be used for interpreting the stored pixel values.

If Pixel Presentation (0008,9205) equals COLOR, the stored values are split into two ranges. The stored values up to one less than the second value of the Red, Green and Blue Palette Color Lookup Table Descriptor (0028,1101-1103) are passed through the gray scale visualization pipeline. The values equal to or greater than the second value of the Red, Green and Blue Palette Color Lookup Table Descriptor (0028,1101-1103) are mapped by the Palette Color LUTs.

### Note

1. Some images may be purely color, and there will be no grayscale range of stored pixel values "below" those that are passed through the color lookup tables.

2. Images containing Supplemental Palette Color LUTs cannot be irreversibly (lossy) compressed, since that would potentially change the index values and result in different colors being rendered.

The complete range of stored pixel values can also be displayed via the grayscale visualization pipeline only, but the information content may be less useful because the color information is not available.

Figure C.8-20. MONOCHROME2 Photometric Interpretation with Supplemental Palette Color Mapping

###### C.8.16.2.1.2 Volumetric Properties

The value of Volumetric Properties (0008,9206) allows applications doing geometric manipulations (e.g., MAX_IP or MPR or planning) to determine if the image is an appropriate candidate for an operation without having to know all the details of the generating application.

Table C.8-133 specifies the Enumerated Values for Volumetric Properties (0008,9206).

Table C.8-133. Volumetric Properties Attribute Values

Enumerated Value Name | Enumerated Value Description
--- | ---
VOLUME | Image contains pixels that represent the volume specified for the image (Examples: Volume Based Calculation Technique (0008,9207) is NONE or MPR).
SAMPLED | The specified frame or each frame within the image will not contain a representation of the average information in the slice direction because the frame was calculated by the non-linear re-sampling of a volume where each pixels of the resulting frame does not contain an average representation of the voxel represented by the frame's pixel. For example a projection (MAX_IP) frame uses the maximum value along a ray for each pixel rather than the average value of the represented voxel.
DISTORTED | Image contains significantly distorted information from what is specified by the image volume attributes. For example this image should not be used in planning or for 3D volume. An example of this image type is a curved reformatted image (CURVED_MPR).
MIXED | Used only as a value in Volumetric Properties (0008,9206) in the Enhanced MR Image Type Module or Enhanced CT Image Type Module if frames within the image SOP Instance contain different values for Volumetric Properties (0008,9206) in the MR Image Frame Type Functional Group or CT Frame Type Functional Group.

### Note

A value of MIXED may be necessary if creating a Legacy Converted Enhanced image and insufficient information is present to specify a more specific value.

###### C.8.16.2.1.3 Volume Based Calculation Technique Attribute

The value of Volume Based Calculation Technique (0008,9207) shall be used to indicate the method used for calculating pixels based on geometry.

Shall have a value of NONE when Value 1 of Image Type (0008,0008) or Value 1 of Frame Type (0008,9007) is ORIGINAL.

Table C.8-134 specifies the Defined Terms for the Volume Based Calculation Technique (0008,9207) attribute.

Table C.8-134. Volume Based Calculation Technique Attribute Values

Defined Term Name | Defined Term Description
--- | ---
MAX_IP | Maximum Intensity Projection
MIN_IP | Minimum Intensity Projection
VOLUME_RENDER | Volume Rendering Projection Volume Rendering Image represents 3D voluminar information constructed from measured voxel intensities covering a 3D volume.
SURFACE_RENDER | Surface Rendering Projection Surface Rendering Image represents 3D surface information constructed from measured voxel intensities covering a 3D volume.
MPR | Multi-Planar Reformat
CURVED_MPR | Curved Multi-Planar Reformat
NONE | Pixels not derived geometrically
MIXED | Used only as a value in Volume Based Calculation Technique (0008,9207) attribute in the Enhanced MR Image Module or MR Spectroscopy Module if frames within the image SOP Instance contain different terms for the Volume Based Calculation Technique attribute in MR Frame Type Functional Group or MR Spectroscopy Frame Type Functional Group.

### Note

A value of MIXED may be necessary if creating a Legacy Converted Enhanced image and insufficient information is present to specify a more specific value.

### C.8.17 Ophthalmic Photography and Tomography Modules

#### C.8.17.1 Ophthalmic Photography Series Module

Table C.8.17.1-1 specifies the attributes that describe an Ophthalmic Photography Series.

Table C.8.17.1-1. Ophthalmic Photography Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Source equipment that produced the Ophthalmic Photography Series. Enumerated Values: OP

#### C.8.17.2 Ophthalmic Photography Image Module

Table C.8.17.2-1 specifies the Attributes that describe an Ophthalmic Photography Image produced by Ophthalmic Photography equipment (OP) imaging Modalities.

Table C.8.17.2-1. Ophthalmic Photography Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.17.2.1.4 for specialization.
Instance Number | (0020,0013) | 1 | A number that identifies this image.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. Enumerated Values: 1 3 See Section C.8.17.2.1.2 for further explanation.
Samples per Pixel Used | (0028,0003) | 1C | The number of samples (planes) containing information. Enumerated Values: 2 Required if different from Samples per Pixel (0028,0002). See Section C.8.17.2.1.2
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. See Section C.8.17.2.1.3
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Enumerated Values: 0
Planar Configuration | (0028,0006) | 1C | Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. Enumerated Values: 2 color-by-pixel
Pixel Spacing | (0028,0030) | 1C | Nominal physical distance at the focal plane (in the retina) between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order. ### Note These values are specified as nominal because the physical distance may vary across the field of the images and the lens correction is likely to be imperfect. Required when Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (SRT, R-1021A,"Fundus Camera"). May be present otherwise.
Content Time | (0008,0033) | 1 | The time the image pixel data creation started.
Content Date | (0008,0023) | 1 | The date the image pixel data creation started.
Acquisition DateTime | (0008,002A) | 1C | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time Synchronized (0018,1800). Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Source Image Sequence | (0008,2112) | 2C | A Sequence that identifies the Images that were used to derive this Image. Required if Image Type Value 1 is DERIVED. Zero or more items shall be included in this sequence. See Section C.7.6.1.1.4 for further explanation.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made, that is what role the source image or frame(s) played in the derivation of this image. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Defined CID 7202 “Source Image Purposes of Reference”.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111) Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1C | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values. Required if Photometric Interpretation (0028,0004) is MONOCHROME2
Calibration Image | (0050,0004) | 3 | Indicates whether a reference object (phantom) of known size is present in the image and was used for calibration. Enumerated Values: YES NO
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: YES NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.

##### C.8.17.2.1 Ophthalmic Photography Image Module Attribute Descriptions

###### C.8.17.2.1.1 Referenced Image Sequence

The Referenced Image Sequence (0008,1140) in the General Image Module (Section C.7.6.1) shall not convey stereoscopic information, which instead shall be encoded using the Stereometric Relationship IOD.

###### C.8.17.2.1.2 Samples Per Pixel and Samples Per Pixel Used

Samples per Pixel (0028,0002) shall be 1 or 3.

Cameras producing 2-color images are required to use a value of 3 for Samples per Pixel (0028,0002) and a value of 2 for Samples per Pixel Used (0028,0003). For 2-color images with a RGB Photometric Interpretation, the R and G channel shall be used and the B channel shall have all values set to zero.

### Note

In the case of Photometric Interpretations typically used for compression such as YBR_FULL_422, the encoding will be as if the RGB values were transformed to YCbCr.

###### C.8.17.2.1.3 Photometric Interpretation

Specifies the intended interpretation of the pixel data.

Enumerated Values:

MONOCHROME2

RGB

YBR_FULL_422

YBR_PARTIAL_420

YBR_ICT

YBR_RCT

###### C.8.17.2.1.4 Image Type

The Image Type attribute (0008,0008) (General Image Module, Section C.7.6.1) identifies important image characteristics in a multiple valued data element. For the Ophthalmic Photography Image IOD, Image Type is specified as a Type 1 attribute and further specialized as follows:

- Value 1 shall identify the Pixel Data Characteristics in accordance with Section C.7.6.1.1.2.

  Enumerated Values for Value 1:

  ORIGINAL

  DERIVED

- Value 2 shall identify the Patient Examination Characteristics in accordance with Section C.7.6.1.1.2.

  Enumerated Values for Value 2:

  PRIMARY

- Value 3 shall only be present if Value 1 is DERIVED.

  Defined Terms for Value 3:

  MONTAGE

- Value 4 (optionally present) shall identify the type of test performed for image acquisition.

  Defined Terms for Value 4:

  COLOR

    a picture take at "white" light; no filters applied

  REDFREE

    a picture take at "green" illumination light; or just the green channel of a color sensor

  RED

    a picture take at "red" illumination light; or just the red channel of a color sensor

  BLUE

    a picture take at "blue" illumination light; or just the blue channel of a color sensor

  FA

    fluorescein injected; a picture taken at fluorescein exciting illumination light; a filter passing just the emitted wavelength to sensor applied

  ICG

    Indocyanine green injected; a picture taken at Indocyanine green exciting illumination light; a filter passing just the emitted wavelength to sensor applied

  ### Note

  A Montage Image is constructed out of several individual images, which also can be exchanged separately. The images used to create the montage image will be included in the source image sequence if those images are also exchanged. A Montage Image is identified as Image Type DERIVED\PRIMARY\MONTAGE

#### C.8.17.3 Ophthalmic Photographic Parameters Module

This Module describes equipment used to create original images.

Table C.8.17.3-1. Ophthalmic Photographic Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Acquisition Device Type Code Sequence | (0022,0015) | 1 | Describes the type of acquisition device Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4202 “Ophthalmic Photography Acquisition Device”.
Illumination Type Code Sequence | (0022,0016) | 2 | Coded value for illumination Zero or one item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4203 “Ophthalmic Photography Illumination”.
Light Path Filter Type Stack Code Sequence | (0022,0017) | 2 | Filters used in the light source path Zero or more items shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4204 “Ophthalmic Filter”.
Light Path Filter Pass-Through Wavelength | (0022,0001) | 3 | Nominal pass-through wavelength of light path filter in nm
Light Path Filter Pass Band | (0022,0002) | 3 | Pass band of light path filter in nm. This Attribute has two Values. The first is the shorter and the second the longer wavelength relative to the peak. The values are for the - 3dB nominal (1/2 of peak) pass through intensity One of the two Values may be zero length, in which case it is a cutoff filter.
Image Path Filter Type Stack Code Sequence | (0022,0018) | 2 | Describes stack of filters used in image path Zero or more items shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4204 “Ophthalmic Filter”.
Image Path Filter Pass-Through Wavelength | (0022,0003) | 3 | Nominal pass-through wavelength of image path filter in nm
Image Path Filter Pass Band | (0022,0004) | 3 | Pass band of image path filter in nm. This Attribute has two Values. The first is the shorter and the second the longer wavelength relative to the peak. The values are for the - 3dB nominal (1/2 of peak) pass through intensity One of the two Values may be zero length, in which case it is a cutoff filter
Lenses Code Sequence | (0022,0019) | 2 | Lenses that were used during the image acquisition Zero or more items shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4205 “Ophthalmic Lens”.
Detector Type | (0018,7004) | 2 | Type of detector used for creating this image. Defined Terms: CCD Charge Coupled Devices CMOS Complementary Metal Oxide Semiconductor
Channel Description Code Sequence | (0022,001A) | 1C | Describes the light color used for each channel to generate the image. Required if this differs from the natural interpretation. ### Note Interpretation and representation of RGB images rely on the assumption that the red channel really contains the red wavelength range of illumination light, the blue channel the blue wavelength range, etc. Some modalities use the RGB Photometric Interpretation as a container representing 3 channels of any illumination wavelength. Shall have the same number of items as the Value of Samples per Pixel Used (0028,0003) if present, or otherwise the value of Samples per Pixel (0028,0002). The channels shall be described in the order in which the channels are encoded.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4206 “Ophthalmic Channel Description”.
Camera Angle of View | (0022,001E) | 3 | The aperture angle of the camera, in degrees

#### C.8.17.4 Ophthalmic Photography Acquisition Parameters Module

This Module describes patient clinical conditions related to the image acquisition.

Table C.8.17.4-1. Ophthalmic Photography Acquisition Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Patient Eye Movement Commanded | (0022,0005) | 2 | Enumerated Values: YES NO
Patient Eye Movement Command Code Sequence | (0022,0006) | 1C | Coded value for patient movement or orientation, which is the intent, and not necessarily the result, based on what the patient is capable of. Required if the value of Patient Eye Movement Commanded (0022,0005) is YES. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4201 “Patient Eye Movement Command”.
Include Table C.8.17.8-2 “Ophthalmic Acquisition Parameters Macro Attributes” |

#### C.8.17.5 Ocular Region Imaged Module

Table C.8.17.5-1 contains IOD Attributes that describe the anatomy contained in an Ophthalmic Photography or Ophthalmic Tomography IOD.

Table C.8.17.5-1. Ocular Region Imaged Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Laterality | (0020,0062) | 1 | Laterality of object imaged (as described in Anatomic Region Sequence (0008,2218)) examined. Enumerated Values: R right eye L left eye B both left and right eye Shall be consistent with any laterality information contained in Primary Anatomic Structure Modifier Sequence (0008,2230), if present. ### Note Laterality (0020,0060) is a Series level Attribute and must be the same for all Images in the Series. Since most Ophthalmic Photographic Image studies contain images of both eyes, the series level attribute will rarely be present.
Relative Image Position Code Sequence | (0022,001D) | 3 | The position of this image on the retina (as defined by a specified nomenclature; the nomenclature is implicit in the code used). Only a single Item is permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4207 “Ophthalmic Image Position”.
Include Table 10-5 “General Anatomy Mandatory Macro Attributes” | Defined CID 4209 “Ophthalmic Anatomic Structure Imaged” for Anatomic Region Sequence

#### C.8.17.6 Ophthalmic Tomography Series Module

Table C.8.17.6-1 specifies the Attributes that identify and describe general information about the Ophthalmic Tomography Series.

Table C.8.17.6-1. Ophthalmic Tomography Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: OPT See Section C.7.3.1.1.1 for further explanation.
Series Number | (0020,0011) | 1 | A number that identifies this Series.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.17.7 Ophthalmic Tomography Image Module

Table C.8.17.7-1 specifies the Attributes that describe an Image produced by Ophthalmic Tomography imaging modalities.

Table C.8.17.7-1. Ophthalmic Tomography Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.7.6.1.1.2 for Enumerated Values and Defined Terms and further explanation.
Samples Per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.7.6.3.1.1 for further explanation. Enumerated Values: 1
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800).
Acquisition Duration | (0018,9073) | 1C | The scan time in seconds used to create all frames of an Ophthalmic Tomography image. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Acquisition Number | (0020,0012) | 1 | A number identifying the single continuous gathering of data over a period of time that resulted in this image.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME2
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. Enumerated Values: 0
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. Enumerated Values: 8 12 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. High Bit (0028,0102) shall be one less than Bits Stored
Presentation LUT Shape | (2050,0020) | 1 | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Concatenation Frame Offset Number | (0020,9228) | 1 | Offset of the first frame in a multi-frame image of a concatenation. Enumerated Values: 0
In-concatenation Number | (0020,9162) | 1 | Identifier for one SOP Instance belonging to a concatenation. Enumerated Values: 1
In-concatenation Total Number | (0020,9163) | 1 | The number of SOP Instances sharing the same Concatenation UID (0020,9161). Enumerated Values: 1
Image Comments | (0020,4000) | 3 | User-defined comments about the image

The value constraints on Concatenation Frame Offset Number (0020,9228), In-concatenation Number (0020,9162), and In-concatenation Total Number (0020,9163) have the effect of requiring the entire image to be in one concatenation.

#### C.8.17.8 Ophthalmic Tomography Acquisition Parameters Module

Table C.8.17.8-1 describes patient clinical conditions related to an Ophthalmic Tomography image acquisition.

Table C.8.17.8-1. Ophthalmic Tomography Acquisition Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Axial Length of the Eye | (0022,0030) | 2 | Axial length of the eye in mm.
Horizontal Field of View | (0022,000C) | 2 | The horizontal field of view in degrees
Include Table C.8.17.8-2 “Ophthalmic Acquisition Parameters Macro Attributes” |

Table C.8.17.8-2. Ophthalmic Acquisition Parameters Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Refractive State Sequence | (0022,001B) | 2 | The refractive state of the imaged eye at the time of acquisition. Zero or one Itemshall be included in this sequence. Zero length means the refractive state was not measured.
>Spherical Lens Power | (0022,0007) | 1 | Sphere value in diopters
>Cylinder Lens Power | (0022,0008) | 1 | Cylinder value in diopters
>Cylinder Axis | (0022,0009) | 1 | Axis value in degrees
Emmetropic Magnification | (0022,000A) | 2 | Emmetropic magnification value (dimensionless). Zero length means the emmetropic magnification was not measured.
Intra Ocular Pressure | (0022,000B) | 2 | Value of intraocular pressure in mmHg. Zero length means the pressure was not measured
Pupil Dilated | (0022,000D) | 2 | Whether or not the patient's pupils were pharmacologically dilated for this acquisition. Enumerated Values: YES NO If this tag is empty, no information is available.
Mydriatic Agent Sequence | (0022,0058) | 2C | Information about the agent administered. Zero or more items shall be included in this sequence. ### Note An empty sequence indicates that an agent was used for dilation, but the name was not entered. Required if the value of Pupil Dilated (0022,000D) is YES.
>Mydriatic Agent Code Sequence | (0022,001C) | 1 | The actual agent administered to dilate the pupil. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4208 “Mydriatic Agent”.
>Mydriatic Agent Concentration | (0022,004E) | 3 | The concentration of the agent.
>Mydriatic Agent Concentration Units Sequence | (0022,0042) | 1C | Units of measure for the Mydriatic Agent Concentration. Only a single Item shall be included in this sequence. Required if Mydriatic Agent Concentration (0022,004E) is present.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 82 “Units of Measurement”.
Degree of Dilation | (0022,000E) | 2C | The degree of the dilation in mm. Required if the value of Pupil Dilated (0022,000D) is YES.

#### C.8.17.9 Ophthalmic Tomography Parameters Module

Table C.8.17.9-1 describes the parameters and characteristics of the acquisition device related to an Ophthalmic Tomography image acquisition.

Table C.8.17.9-1. Ophthalmic Tomography Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Acquisition Device Type Code Sequence | (0022,0015) | 1 | Describes the type of acquisition device. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4210 “Ophthalmic Tomography Acquisition Device”.
Light Path Filter Type Stack Code Sequence | (0022,0017) | 2 | Filters used in the light source path. Zero or more items shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4204 “Ophthalmic Filter”.
>Light Path Filter Pass-Through Wavelength | (0022,0001) | 3 | Nominal pass-through wavelength of light path filter in nm
>Light Path Filter Pass Band | (0022,0002) | 3 | Pass band of light path filter in nm. This Attribute has two Values. The first is the shorter and the second the longer wavelength relative to the peak. The values are for the - 3dB nominal (1/2 of peak) pass through intensity. One of the two Values may be zero length, in which case it is a cutoff filter.
Detector Type | (0018,7004) | 1 | Type of detector used for creating this image. Defined Terms: CCD Charge Coupled Device CMOS Complementary Metal Oxide Semiconductor PHOTO Photodetector INT Interferometer
Illumination Wave Length | (0022,0055) | 1C | Wavelength of the illuminator in nm. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Illumination Power | (0022,0056) | 1C | Power of the illuminator in microwatts at corneal plane. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (SRT, A-00FBE,"Optical Coherence Tomography Scanner"). May be present otherwise.
Illumination Bandwidth | (0022,0057) | 1C | Bandwidth of the illuminator in nm. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Depth Spatial Resolution | (0022,0035) | 1C | The inherent limiting resolution in microns for depth of the acquisition equipment for high contrast objects for the data gathering and reconstruction technique chosen. If variable, the value at the center of the scanning volume. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Maximum Depth Distortion | (0022,0036) | 1C | Maximum distortion in depth direction in % of Depth Spatial Resolution. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (SRT, A-00FBE,"Optical Coherence Tomography Scanner"). May be present otherwise.
Along-scan Spatial Resolution | (0022,0037) | 1C | The inherent limiting resolution in microns of the acquisition equipment in the direction of a row. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Maximum Along-scan Distortion | (0022,0038) | 1C | Maximum distortion in along-scan direction in % of Along-scan Spatial Resolution. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Across-scan Spatial Resolution | (0022,0048) | 1C | The inherent limiting resolution in microns of the acquisition equipment perpendicular to the slice. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.
Maximum Across-scan Distortion | (0022,0049) | 1C | Maximum distortion in across-scan direction in % of cross-scan Spatial Resolution. Required if Acquisition Device Type Code Sequence (0022,0015) contains an item with the value (A-00FBE, SRT, "Optical Coherence Tomography Scanner"). May be present otherwise.

#### C.8.17.10 Ophthalmic Tomography Functional Group Macros

##### C.8.17.10.1 Ophthalmic Frame Location Macro

Table C.8.17.10-1 specifies the attributes of the Ophthalmic Frame Location Functional Group Macro. This is used to provide a frame location relative to one or more referenced images. This macro describes a frame perpendicular or parallel to the reference image; it describes column locations for frames that are scanned either uniformly along a line segment, or with a non-uniform spacing along any trajectory in the reference image.

Table C.8.17.10-1. Ophthalmic Frame Location Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Frame Location Sequence | (0022,0031) | 1 | Specifies the column locations for this frame in terms of locations on a referenced image. One or more Items shall be included in this sequence.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 3 | Describes the purpose for which the reference is made. Only a single Item is permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined Code Concept for Purpose of Reference is (121311, DCM, "Localizer")
>Reference Coordinates | (0022,0032) | 1 | Image coordinates for the points on the referenced image that correspond to the points on this frame. See Section C.8.17.10.1.1.
>Depth of Transverse Image | (0022,0041) | 2C | Relative position in microns signifying the location of a Transverse image in the z-axis. Required if Ophthalmic Image Orientation (0022,0039) is TRANSVERSE.
>Ophthalmic Image Orientation | (0022,0039) | 1 | Enumerated Values: LINEAR NONLINEAR TRANSVERSE

###### C.8.17.10.1.1 Reference Coordinates

A frame can be described in terms of its "position" on another image. In the case of ophthalmic tomography (OPT) images with longitudinal orientation, the OPT image corresponds to a vertical slice along a trajectory on the referenced image. Each column of the OPT frame is nominally perpendicular to the image. Therefore, each column of the OPT frame can also correspond to a particular pixel on an associated image. It is normal in OPT analysis to indicate the location of the OPT slice by showing the corresponding pixel locations on the image. For Transverse frames, the position is indicated by two corners of a rectangle.

### Note

The simple geometric relationship modules are not practical to use for describing the relationship between OPT and retinal photography images. The retinal surface is highly curved, and the optical path is influenced by the lens and other eye structures. It is impractical to measure all of the geometric and optical properties of the eye to the degree needed to establish the relationship by geometric computation. It is easy to capture a retinal image and the slice path on that image as part of the OPT acquisition.

The OPT columns for a retinal slice are not strictly perpendicular to the retina and there are minor systematic distortions as a result. This DICOM functional group does not attempt to capture the data needed to measure or correct for these effects, except for the presence of the Maximum Along-scan Distortion Attribute (0022,0038).

The relationship between the columns in the image frame and the reference image are illustrated in Figure C.8.17.10-1.

Frames can be captured using a linear scan with uniform column spacing. This permits the column position to be described by giving the endpoints of the line segment that was scanned. Figure C.8.17.10-1 shows such a scan labeled as "OCT Frame 1". When describing this frame using the Linear Column Locations Functional Group Macro, the sequence attributes would contain:

1. The Attributes of the Image SOP Instance Reference Macro would point to a frame of the reference image.

2. Reference Coordinates (0022,0032) would contain values that give the row and column coordinates for the image pixel on the referenced image that corresponds to the first column of the OPT Frame 1 and the row and column coordinates that corresponds to the last column of the OPT Frame 1.

Frames can also be taken along curved paths, or with non-uniform spacing. These frames cannot be described by just the two endpoints. These frames are described by specifying the referenced image pixel coordinates for each column in the frame. The frame labeled "OCT Frame 2" illustrates this kind of relationship. The Non-linear Column Locations Functional Group Macro description for this frame would contain:

1. The Attributes of the Image SOP Instance Reference Macro would point to a frame of the reference image.

2. Reference Coordinates (0022,0032) would contain 2N integer values. Their contents would be:

   1-2 (e,f)

   … other values

   2L-1, 2L (g,h)

   … other values

   2N-1, 2N (x,y)

A three dimensional OPT raster scan image would be described by a series of Linear Column Location Sequences, one for each frame.

### Note

One expected use of column location is the automatic generation of annotation graphics display. The slice location can be indicated and dynamically controlled on the reference image while examining the observed slices. This replaces the relatively inflexible practice of creating a modified retinal image with burned in annotation to indicate the slice locations.

Figure C.8.17.10-1. Relationship of Longitudinal (Nominally Perpendicular) OCT Frames to Reference Frame

In the case of ophthalmic tomography (OPT) images with a transverse orientation, the OPT image corresponds to a sub-rectangle of the reference image. See Figure C.8.17.10-2. The OPT frame is nominally parallel to the reference image. Therefore, each corner of the OPT frame can also correspond to a particular pixel on an associated image. It is assumed that the edges of OPT frame are exactly parallel to the edges of the reference image.

Figure C.8.17.10-2. Relationship of Transverse (Nominally Parallel) OCT Frame to Reference Frame

### C.8.18 Stereometric Modules

#### C.8.18.1 Stereometric Series Module

Table C.8.18.1-1 specifies the Attributes that describe a Stereometric Series produced by Ophthalmic Photography equipment (OP) imaging Modalities.

Table C.8.18.1-1. Stereometric Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Source equipment that produced the Stereometric Series. Enumerated Values: SMR

#### C.8.18.2 Stereometric Relationship Module

The stereometric relationship module is used to identify pairs of images that may be viewed in stereo. It is possible that the same image or frame may be a member of multiple pairs. The images forming a pair shall be in different SOP Instances. The images forming a pair can be in different Series. All Instances referenced in this Module shall be in the same Study as the Instance in which the Module occurs.

Table C.8.18.2-1. Stereometric Relationship Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Stereo Pairs Sequence | (0022,0020) | 1 | Sequence of items identifying pairs of images. One or more items shall be included in this sequence.
>Stereo Baseline Angle | (0022,0010) | 3 | Stereo separation angle in degrees
>Stereo Baseline Displacement | (0022,0011) | 3 | Horizontal displacement of instrument between left and right image in mm
>Stereo Horizontal Pixel Offset | (0022,0012) | 3 | Horizontal displacement of right image relative to left image in pixels for optimal display. Offset of right image to right means positive value.
>Stereo Vertical Pixel Offset | (0022,0013) | 3 | Vertical displacement of right image relative to left image in pixels for optimal display. Offset of right image downwards means positive value.
>Stereo Rotation | (0022,0014) | 3 | Rotation of right image relative to left image in degrees for optimal display. The rotation of the right image against the left image counterclockwise is positive, rotation around the center is assumed.
>Left Image Sequence | (0022,0021) | 1 | Left Image of the Pair. Only a single Item shall be included in this sequence.
>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” | The Referenced SOP Instance UID (0008,1155) shall not be the same as the Referenced SOP Instance UID (0008,1155) of the Right Image Sequence (0022,0022).
>Right Image Sequence | (0022,0022) | 1 | Right Image of the Pair. Only a single Item shall be included in this sequence.
>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” | The Referenced SOP Instance UID (0008,1155) shall not be the same as the Referenced SOP Instance UID (0008,1155) of the Left Image Sequence (0022,0021).

##### C.8.18.2.1 Stereometric Relationship Module Attribute Descriptions

###### C.8.18.2.1.1 Left and Right Image Sequences

The images referenced by the Left Image Sequence (0022,0021) and Right Image Sequence (0022,0022) in a single Stereo Pairs Sequence Item shall have the same values for Rows (0028,0010) and the same values for Columns (0028,0011).

The reference may be to images with a single frame, all the frames of images with multiple frames, or one or more selected frames within an image with multiple frames. If multiple frames are selected, the same number of frames shall be referenced from both sequences.

### C.8.19 Enhanced XA/XRF Image

#### C.8.19.1 XA/XRF Series Module

The XA/XRF X-Ray IODs use the General Series module described in Section C.7.3.1, specialized by the XA/XRF Series Module, to describe the DICOM Series Entity specified in Section A.47 and Section A.48. It is defining what constitutes a Series for the context of projection XA/XRF device.

Table C.8.19.1-1 specifies the Attributes that identify and describe general information about the XA/XRF Series.

Table C.8.19.1-1. XA/XRF Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: XA RF See Section C.7.3.1.1.1 for further explanation.
Series Number | (0020,0011) | 1 | A number that identifies this Series.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.19.2 Enhanced XA/XRF Image Module

This section describes the Enhanced XA/XRF Image Module. Table C.8.19.2-1 contains IOD Attributes that describe a XA/XRF Image by specializing Attributes of the General Image and Image Pixel Modules, and adding additional Attributes.

Table C.8.19.2-1. Enhanced XA/XRF Image Module Table

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.19.2.1.1 for specialization.
Planes in Acquisition | (0018,9410) | 1 | The multiplicity of planes used simultaneously during the acquisition. See Section C.8.19.2.1.3.
Plane Identification | (0018,9457) | 1C | Identification of the plane used to acquire this image. Defined Terms: MONOPLANE PLANE A PLANE B ### Note MONOPLANE may only be used for a single plane system PLANE A and PLANE B must be used for two plane systems, independent if the acquisition is single plane or biplane. The value has to be in accordance with the value of Planes in Acquisition (0018,9410). If this value is SINGLE PLANE all three Defined Term are applicable. Required if Planes in Acquisition (0018,9410) is not equal to UNDEFINED.
Acquisition Number | (0020,0012) | 3 | A number identifying the single continuous gathering of data over a period of time that resulted in this image.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started. ### Note The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. Enumerated Values: 8 9 10 11 12 13 14 15 16 See Section C.8.19.2.1.2 for specialization.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Samples per Pixel | (0028,0002) | 1 | Number of samples (color planes) in this image shall have a value of 1.
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Shall have the value: 0000H = Unsigned Integer.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME1 MONOCHROME2
Acquisition Protocol Name | (0018,9423) | 3 | User defined name of the protocol used to acquire this image.
Acquisition Protocol Description | (0018,9424) | 3 | User defined description of the protocol used to acquire this image.
Scan Options | (0018,0022) | 3 | Identifies any acquisition technique that was used during the acquisition of the image. Defined Terms: TOMO Tomography CHASE Bolus Chasing STEP Stepping ROTA Rotation
Content Qualification | (0018,9004) | 1 | Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See Section C.8.13.2.1.1 for further explanation.
Patient Orientation Code Sequence | (0054,0410) | 1C | Sequence that describes the orientation of the patient with respect to gravity. See Section C.8.11.5.1.2 for further explanation. Only a single Item shall be included in this Sequence. Required if Positioner Type (0018,1508) equals CARM and C-arm Positioner Tabletop Relationship (0018,9474) equals YES. May be present otherwise.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 19 “Patient Orientation”.
>Patient Orientation Modifier Code Sequence | (0054,0412) | 1C | Patient Orientation Modifier. Required if needed to fully specify the orientation of the patient with respect to gravity. Only a single Item shall be included in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 20 “Patient Orientation Modifier”.
Patient Gantry Relationship Code Sequence | (0054,0414) | 2C | Sequence that describes the orientation of the patient with respect to the head of the table. See Section C.8.4.6.1.3 for further explanation. Zero or one item shall be included in this sequence. Required if Positioner Type (0018,1508) equals CARM and C-arm Positioner Tabletop Relationship (0018,9474) equals YES. May be present otherwise.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Baseline CID 21 “Patient Equipment Relationship”.
Examined Body Thickness | (0010,9431) | 3 | Body thickness in mm at examination location perpendicular to the table top for this series. ### Note This is intended for estimation of the thickness of the patient at the tabletop, not for precise calculation of the size of the object in the X-Ray beam (see Calculated Anatomy Thickness (0018,9452) attribute). For example, used to estimate the value range of the Distance Object to Table Top (0018,9403) attribute.
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not the image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Referenced Other Plane Sequence | (0008,9410) | 1C | The images of the corresponding plane for a Biplane acquisition device. Only a single Item shall be included in this Sequence. Required if Planes in Acquisition (0018,9410) is BIPLANE.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
Referenced Image Evidence Sequence | (0008,9092) | 1C | Full set of Composite SOP Instances referred to inside the Referenced Image Sequences of this SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Source Image Evidence Sequence | (0008,9154) | 1C | Full set of Composite SOP Instances referred to inside the Source Image Sequences of this SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Source Image Sequence (0008,2112) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Instance Sequence | (0008,114A) | 3 | Non-image Composite SOP Instances that are significantly related to this Image, including waveforms that may or may not be temporally synchronized with this image. One or more Items are permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Code describing the purpose of the reference to the SOP Instances. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7004 “Waveform Purposes of Reference” for referenced waveforms.
Image Comments | (0020,4000) | 3 | User-defined comments about the image.
Quality Control Image | (0028,0300) | 3 | Indicates whether or not this image is a quality control or phantom image. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not be a quality control or phantom image.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this Sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6 for further explanation.
Presentation LUT Shape | (2050,0020) | 1 | Specifies a predefined identity transformation for the Presentation LUT such that the output of all grayscale transformations, if any, are defined to be in P-Values. Enumerated Values: IDENTITY output is in P-Values - shall be used if Photometric Interpretation (0028,0004) is MONOCHROME2 INVERSE output after inversion is in P-Values - shall be used if Photometric Interpretation (0028,0004) is MONOCHROME1.

##### C.8.19.2.1 Enhanced XA/XRF Image Module Attribute Description

###### C.8.19.2.1.1 Image Type and Frame Type

In addition to the requirements specified in Section C.8.16.1 Image Type, the following additional requirements and Defined Terms are specified.

###### C.8.19.2.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.19.2.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.19.2.1.1.3 Image Flavor

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.3. No additional requirements or Defined Terms.

###### C.8.19.2.1.1.4 Derived Pixel Contrast

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.4. The value shall be NONE.

###### C.8.19.2.1.2 Bits Allocated and Bits Stored

Table C.8.19.2-2 specifies the allowed combinations of Bits Allocated (0028,0100) and Bits Stored (0028,0101).

Table C.8.19.2-2. Allowed Combinations of Attribute Values for Bits Allocated and Bits Stored

Bits Allocated | Bits Stored
--- | ---
8 | 8
16 | 9 to 16

###### C.8.19.2.1.3 Planes in Acquisition

The Planes in Acquisition (0018,9410) attribute identifies the multiplicity of planes used simultaneously during the acquisition.

Enumerated Values:

SINGLE PLANE

  Image is a single plane acquisition

BIPLANE

  Image is part of a Bi-plane acquisition

UNDEFINED

  Image is created by using data from one or two planes (e.g., reconstructed projection). May only be used when Image Type Value 1 equals DERIVED.

#### C.8.19.3 XA/XRF Acquisition Module

Table C.8.19.3-1 specifies the attributes of the XA/XRF Acquisition Module.

Table C.8.19.3-1. XA/XRF Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
KVP | (0018,0060) | 1 | Average of the peak kilo voltage outputs of the X-Ray generator used for all frames.
Radiation Setting | (0018,1155) | 1 | Identify the general level of X-Ray dose exposure. Enumerated Values: SC low dose exposure generally corresponding to fluoroscopic settings (e.g., preparation for diagnostic quality image acquisition) GR high dose for diagnostic quality image acquisition (also called digital spot or cine)
X-Ray Tube Current in mA | (0018,9330) | 1C | Average of the nominal X-Ray tube currents in milliamperes for all frames. Required if Exposure in mAs (0018,9332) is not present. May be present otherwise.
Exposure Time in ms | (0018,9328) | 1C | Duration of X-Ray exposure in milliseconds. See Section C.8.7.2.1.1. Required if Exposure in mAs (0018,9332) is not present. May be present otherwise.
Exposure in mAs | (0018,9332) | 1C | The exposure expressed in milliampereseconds, for example calculated from Exposure Time and X-Ray Tube Current. Required if either Exposure Time in ms (0018,9328) or X-Ray Tube Current in mA (0018,9330) are not present. May be present otherwise.
Average Pulse Width | (0018,1154) | 1 | Average width of X-Ray pulse in msec.
Acquisition Duration | (0018,9073) | 1 | The time in seconds needed for the complete acquisition. See Section C.7.6.16.2.2.1 for further explanation
Radiation Mode | (0018,115A) | 1 | Specifies X-Ray radiation mode. Defined Terms: CONTINUOUS PULSED
Focal Spot(s) | (0018,1190) | 3 | Nominal focal spot size in mm used to acquire this image.
Anode Target Material | (0018,1191) | 3 | The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
Rectification Type | (0018,1156) | 3 | Type of rectification used in the X-Ray generator. Defined Terms: SINGLE PHASE THREE PHASE CONST POTENTIAL
X-Ray Receptor Type | (0018,9420) | 1 | Identifies with type of X-Ray receptor is used. Enumerated Values: IMG_INTENSIFIER DIGITAL_DETECTOR
Distance Receptor Plane to Detector Housing | (0018,9426) | 2 | Distance in mm between the receptor plane and the detector housing. The direction of the distance is positive from receptor plane to X-Ray source. ### Note A negative value is allowed in the case of an image intensifier the receptor plane can be a virtual plane located outside the detector housing depending the magnification factor of the intensifier. A negative value is not applicable for the digital detector. Used to calculate the pixel size of the plane in the patient when markers are used, and they are placed on the detector housing.
Positioner Type | (0018,1508) | 1 | Defined Terms: CARM COLUMN ### Note The term CARM can apply to any positioner with 2 degrees of freedom of rotation of the X-Ray beam about the Imaging Subject. The term COLUMN can apply to any positioner with 1 degree of freedom of rotation of the X-Ray beam about the Imaging Subject.
C-arm Positioner Tabletop Relationship | (0018,9474) | 1C | Describes for C-arm positioner type systems if positioner and tabletop has the same geometrical reference system. Enumerated Values: YES NO ### Note The value NO is intended for mobile systems where there is no table fixed to the system Required if Positioner Type (0018,1508) equals CARM.
Acquired Image Area Dose Product | (0018,9473) | 2 | X-Ray dose, measured in dGy*cm*cm, to which the patient was exposed for the acquisition of this image only. ### Note The sum of the Image Area Dose Product of all images of a Series or a Study may not result in the actual area dose product to which the patient was exposed. This may be an estimated value based on assumptions about the patient's body size and habitus.

#### C.8.19.4 X-Ray Image Intensifier Module

Table C.8.19.4-1 specifies the attributes of the X-Ray Image Intensifier Module.

Table C.8.19.4-1. X-Ray Image Intensifier Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Intensifier Size | (0018,1162) | 1 | Physical diameter of the maximum active area X-Ray intensifier in mm. ### Note This attribute does not specify the field of view. The attribute Field of View Dimension(s) in Float (0018,9461) is intended for this value.
Intensifier Active Shape | (0018,9427) | 1 | Shape of the active area used for acquiring this image. Enumerated Values: RECTANGLE ROUND HEXAGONAL ### Note This may be different from the Field of View Shape (0018,1147), and should not be assumed to describe the stored image.
Intensifier Active Dimension(s) | (0018,9428) | 1 | Dimensions in mm of the active area used for acquiring this image. If Intensifier Active Shape (0018,9427) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of the circle circumscribing the hexagon. ### Note This may be different from the Field of View Dimension(s) in Float (0018,9461), and should not be assumed to describe the stored image.

#### C.8.19.5 X-Ray Detector Module

Table C.8.19.5-1 contains IOD Attributes that describe an X-Ray detector.

Table C.8.19.5-1. X-Ray Detector Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
Physical Detector Size | (0018,9429) | 1 | Dimensions of the physical detector measured in mm as a row size followed by a column size.
Position of Isocenter Projection | (0018,9430) | 1C | Position of the Isocenter projection on the detector plane measured in fractional physical detector elements as a distance along the column direction followed by a distance along the row direction from the center of the TLHC detector element of a rectangle circumscribing the physical detector area. Required if Isocenter Reference System Sequence (0018,9462) is present.

#### C.8.19.6 Enhanced XA/XRF Image Functional Group Macros

The following sections contain Functional Group Macros specific to the Enhanced XA Image IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".".

##### C.8.19.6.1 X-Ray Frame Characteristics Macro

Table C.8.19.6-1 specifies the attributes of the XA/XRF Frame Characteristics Functional Group Macro.

Table C.8.19.6-1. X-Ray Frame Characteristics Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
XA/XRF Frame Characteristics Sequence | (0018,9412) | 1 | A sequence that describes general characteristics of this frame. Only a single Item shall be included in this sequence.
>Derivation Description | (0008,2111) | 3 | A text description of how this frame was derived. See Section C.8.7.1.1.5 for further explanation.
>Derivation Code Sequence | (0008,9215) | 3 | A coded description of how this frame was derived. See Section C.7.6.1.1.3 for further explanation. One or more Items are permitted in this Sequence. More than one Item indicates that successive derivation steps have been applied.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7203 “Image Derivation”.
>Acquisition Device Processing Description | (0018,1400) | 3 | Indicates any visual processing performed on the frame prior to exchange. See Section C.8.7.1.1.3.
>Acquisition Device Processing Code | (0018,1401) | 3 | Code representing the device-specific processing associated with the frame (e.g., Organ Filtering code) ### Note This Code is manufacturer specific but provides useful annotation information to the knowledgeable observer.

##### C.8.19.6.2 X-Ray Field of View Macro

Table C.8.19.6-2 specifies the attributes of the X-Ray Field of View Functional Group Macro.

Table C.8.19.6-2. X-Ray Field of View Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Field of View Sequence | (0018,9432) | 1 | Sequence containing the field of view for this frame. Only a single item shall be included in this sequence.
>Field of View Shape | (0018,1147) | 3 | Shape of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). Enumerated Values: RECTANGLE ROUND HEXAGONAL
>Field of View Dimension(s) in Float | (0018,9461) | 3 | Dimensions in mm of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). If Field of View Shape (0018,1147) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of the circle circumscribing the hexagon.
>Field of View Origin | (0018,7030) | 1C | Offset of the TLHC of a rectangle circumscribing the Field of View, i.e., the image pixels stored in Pixel Data (7FE0,0010) before rotation or flipping, from the TLHC of the physical detector area measured in physical detector pixels as a row offset followed by a column offset. See Section C.8.11.4.1.1 for further explanation. Required if X-Ray Receptor Type (0018,9420) is present and equals DIGITAL_DETECTOR. May be present otherwise.
>Field of View Rotation | (0018,7032) | 1 | Clockwise rotation in degrees of Field of View, i.e., the image pixels stored in Pixel Data (7FE0,0010), relative to the physical detector. Enumerated Values: 0 90 180 270 See Section C.8.11.4.1.1 for further explanation.
>Field of View Horizontal Flip | (0018,7034) | 1 | Whether or not a horizontal flip has been applied to the Field of View, i.e., the image pixels stored in Pixel Data (7FE0,0010), after rotation relative to the physical detector as described in Field of View Rotation (0018,7032). Enumerated Values: NO YES See Section C.8.11.4.1.1 for further explanation.
>Field of View Description | (0018,9433) | 3 | Manufacturer defined description of the field of view selected during acquisition.

##### C.8.19.6.3 X-Ray Exposure Control Sensing Regions Macro

Table C.8.19.6-3 specifies the attributes that describe the region targeted as area where the x-ray dose value is estimated.

Table C.8.19.6-3. X-Ray Exposure Control Sensing Regions Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Exposure Control Sensing Regions Sequence | (0018,9434) | 1 | Sequence containing the Exposure Control Sensing Region for this frame. One or more items shall be included in this sequence.
>Exposure Control Sensing Region Shape | (0018,9435) | 1 | Shape of the Exposure Control Sensing Region. Enumerated Values: RECTANGULAR CIRCULAR POLYGONAL
>Exposure Control Sensing Region Left Vertical Edge | (0018,9436) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is RECTANGULAR. Location of the left edge of the rectangular Exposure Control Sensing Region expressed as effective pixel column. See Section C.8.19.6.3.1.
>Exposure Control Sensing Region Right Vertical Edge | (0018,9437) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is RECTANGULAR. Location of the right edge of the rectangular Exposure Control Sensing Region expressed as effective pixel column. See Section C.8.19.6.3.1.
>Exposure Control Sensing Region Upper Horizontal Edge | (0018,9438) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is RECTANGULAR. Location of the upper edge of the rectangular Exposure Control Sensing Region expressed as effective pixel row. See Section C.8.19.6.3.1.
>Exposure Control Sensing Region Lower Horizontal Edge | (0018,9439) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is RECTANGULAR. Location of the lower edge of the rectangular Exposure Control Sensing Region expressed as effective pixel row. See Section C.8.19.6.3.1.
>Center of Circular Exposure Control Sensing Region | (0018,9440) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is CIRCULAR. Location of the center of the circular Exposure Control Sensing Region expressed as effective pixel row and column. See Section C.8.19.6.3.1.
>Radius of Circular Exposure Control Sensing Region | (0018,9441) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is CIRCULAR. Radius of the circular Exposure Control Sensing Region expressed as effective number of pixels along the row direction. See Section C.8.19.6.3.1.
>Vertices of the Polygonal Exposure Control Sensing Region | (0018,9442) | 1C | Required if Exposure Control Sensing Region Shape (0018,9435) is POLYGONAL. Multiple Values where the first set of two values are: row of the origin vertex; column of the origin vertex. Two or more pairs of values follow and are the effective pixel row and column coordinates of the other vertices of the polygon Exposure Control Sensing Region. Polygon Exposure Control Sensing Regions are implicitly closed from the last vertex to the origin vertex and all edges shall be non-intersecting except at the vertices. See Section C.8.19.6.3.1.

###### C.8.19.6.3.1 X-Ray Exposure Control Sensing Regions Attributes

The Exposure Control Sensing Region Left Vertical Edge (0018,9436), Exposure Control Sensing Region Right Vertical Edge (0018,9437), Exposure Control Sensing Region Upper Horizontal Edge (0018,9438), Exposure Control Sensing Region Lower Horizontal Edge (0018,9439) and Center of Circular Exposure Control Sensing Region (0018,9440) may have a negative value when the point defined by the attribute lies outside the left or upper border of the pixel data matrix. The top left pixel of the image has a pixel row and column value of 1.

##### C.8.19.6.4 X-Ray Frame Pixel Data Properties Macro

Table C.8.19.6-4 specifies the attributes of the X-Ray Frame Pixel Data Properties Functional Group Macro.

Table C.8.19.6-4. X-Ray Frame Pixel Data Properties Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Pixel Data Properties Sequence | (0028,9443) | 1 | Sequence containing the pixel data properties for this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the values of Image Type (0008,0008). See Section C.8.19.2.1.1.
>Pixel Intensity Relationship | (0028,1040) | 1 | The relationship between the Pixel and the X-Ray beam intensity. See Section C.8.19.6.4.1.1.
>Pixel Intensity Relationship Sign | (0028,1041) | 1 | The sign of the relationship between the Pixel sample values stored in Pixel Data (7FE0,0010) and the X-Ray beam intensity. Enumerated Values: 1 Lower pixel values correspond to less X-Ray beam intensity -1 Higher pixel values correspond to less X-Ray beam intensity See Section C.8.11.3.1.2 for further explanation.
>Imager Pixel Spacing | (0018,1164) | 1C | Physical distance measured at the receptor plane of the detector between the centers of each pixel specified by a numeric pair - row spacing value (delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. The value of this attribute shall never be adjusted to account for calibration against an object of known size; Pixel Spacing (0028,0030) is specified for that purpose. It is only allowed to be adjusted to compensate for the change of the Field of View Dimension(s) in Float (0018,9461) attribute. See Section C.8.19.6.4.1.2 Required if Image Type (0008,0008) Value 1 equals ORIGINAL. May be present otherwise. ### Note These values are the actual pixel spacing distances of the stored pixel values of an image.
>Pixel Data Area Origin Relative To FOV | (0018,7036) | 3 | Offset of the TLHC of the image stored in Pixel Data (7FE0,0010) from the TLHC of the Field Of View Area after FOV rotation and Flip. It is measured in image stored pixels as a row offset followed by a column offset. ### Note Due to the differences in image stored pixel and detector element spacing, one may expect this attribute to have non-integer values. See Section C.8.19.6.4.1.3.
>Pixel Data Area Rotation Angle Relative To FOV | (0018,7038) | 3 | Angle clockwise of the row direction of the image stored in Pixel Data (7FE0,0010) relative to the row direction of the Field Of View Area after FOV rotation and Flip. It is measured in degrees. See Section C.8.19.6.4.1.3.
>Geometrical Properties | (0028,9444) | 1 | Geometrical characteristics of the pixel data to indicate whether pixel spacing is uniform for all pixels or not. Enumerated Values: UNIFORM NON_UNIFORM
>Geometric Maximum Distortion | (0028,9445) | 2C | The percentage of the maximum deviation of the pixel spacing values of images for which the geometric properties are non-uniform. ### Note This attribute may be used to judge the result of measurements, 3D reconstructions, etc. Required if Geometrical Properties (0028,9444) equals NON_UNIFORM.
>Image Processing Applied | (0028,9446) | 1 | The type or a combination of types of image processing applied to the pixel data before being stored. Defined Terms: DIGITAL_SUBTR HIGH_PASS_FILTER LOW_PASS_FILTER MULTI_BAND_FLTR FRAME_AVERAGING NONE

###### C.8.19.6.4.1 X-Ray Frame Pixel Data Properties Attributes

###### C.8.19.6.4.1.1 Pixel Intensity Relationship

Pixel Intensity Relationship (0028,1040) shall identify the relationship of the pixel values to the X-Ray beam intensity.

Defined Terms:

LIN

  Approximately proportional to X-Ray beam intensity.

LOG

  Non-linear "Log Function"; A Pixel Intensity Relationship LUT shall be included with the image to allow it to be mapped back to its proportional value to X-Ray beam intensity.

OTHER

  Not proportional to X-Ray beam intensity. If a TO_LINEAR Pixel Intensity Relationship LUT item is supplied, scaling back to X-Ray beam intensity is possible.

### Note

1. When the relationship can be better defined (e.g., square root data) a more precise Defined Term can be used than OTHER.

2. Providing a TO_LINEAR Pixel Intensity Relationship LUT is encouraged.

###### C.8.19.6.4.1.2 Imager Pixel Spacing

The two values of the Imager Pixel Spacing (0018,1164) attribute are related to the value(s) of the Field of View Dimension(s) in Float (0018,9461) attribute in the X-Ray Field of View Functional Group of this frame and the values of the Rows (0028,0010) and Columns (0028,0011) attributes.

The value(s) of Field of View Dimension(s) in Float (0018,9461) may change on a frame by frame base. The values of the Rows and Columns attributes are equal for all frames. The relationship between the attributes depends on the Field of View Shape (0018,1147) attribute:

If the Field of View Shape (0018,1147) attribute equals RECTANGLE:

Imager Pixel Spacingrow spacing = FOV Dimensionrow dimension / Rows

Imager Pixel Spacingcolumn spacing = FOV Dimensioncolumn dimension / Columns

If the Field of View Shape (0018,1147) attribute equals ROUND or HEXAGONAL:

Imager Pixel Spacingrow spacing = FOV Dimensiondiameter / Rows

Imager Pixel Spacingcolumn spacing = FOV Dimensiondiameter / Columns

###### C.8.19.6.4.1.3 Pixel Data Area Relative to FOV

In the case where the Field of View does not have the same size as the stored Pixel Data (7FE0,0010), the stored Pixel Data (7FE0,0010) may be the result of cropping, rotation, resizing and/or padding of the Field of View. The following Attributes specify the relationship of the Pixel Data area to the Field Of View Area:

- Pixel Data Area Origin Relative to FOV (0018,7036)

- Pixel Data Area Rotation Angle Relative to FOV (0018,7038)

### Note

In order to make use of the Pixel Data Area Origin Relative to FOV (0018,7036), the Imager Pixel Spacing (0018,1164) is needed.

Figure C.8.19.6.4-1. Explanation of Pixel Data Area Attributes

##### C.8.19.6.5 X-Ray Frame Detector Parameters Macro

Table C.8.19.6-5 specifies the attributes containing the X-Ray Frame Detector Parameters Functional Group Macro.

Table C.8.19.6-5. X-Ray Frame Detector Parameters Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Detector Parameters Sequence | (0018,9451) | 1 | Sequence containing the detector properties for this frame. Only a single Item shall be included in this sequence.
>Detector Active Time | (0018,7014) | 3 | Time in mSec that the detector is active during acquisition of this image. ### Note This activation window overlaps the time of the X-Ray exposure as defined by Exposure Time in ms (0018,9328) and Detector Activation Offset From Exposure (0018,7016).
>Detector Activation Offset From Exposure | (0018,7016) | 3 | Offset time in mSec that the detector becomes active after the X-Ray beam is turned on during acquisition of this image. May be negative.

##### C.8.19.6.6 X-Ray Calibration Device Usage Macro

Table C.8.19.6-6 specifies the attributes containing the X-Ray Calibration Device Usage Functional Group Macro.

Table C.8.19.6-6. X-Ray Calibration Device Usage Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Calibration Sequence | (0018,9455) | 1 | Sequence containing the calibration flag for this frame. Only a single Item shall be included in this sequence.
>Calibration Image | (0050,0004) | 1 | Indicates whether a reference object (phantom) of known size is present in the frame and was used for calibration. Enumerated Values: YES NO ### Note Device is identified using the Device module. See Section C.7.6.12.

##### C.8.19.6.7 X-Ray Object Thickness Macro

Table C.8.19.6-7 specifies the attributes containing the X-Ray Object Thickness Group macro.

Table C.8.19.6-7. X-Ray Object Thickness Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Object Thickness Sequence | (0018,9456) | 1 | Sequence containing object thickness for this frame. Only a single Item shall be included in this sequence.
>Calculated Anatomy Thickness | (0018,9452) | 1 | The physical thickness in mm of the anatomic region of interest as specified in the Anatomic Region Sequence (0008,2218) in the direction of the center of the beam. ### Note The value takes in account the position relative to object and the X-Ray source - detector axis.

##### C.8.19.6.8 X-Ray Frame Acquisition Macro

Table C.8.19.6-8 specifies the attributes containing the X-Ray Frame Acquisition Functional Group Macro.

Table C.8.19.6-8. X-Ray Frame Acquisition Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Frame Acquisition Sequence | (0018,9417) | 1 | Sequence containing the acquisition parameters for this frame. Only a single Item shall be included in this sequence.
>KVP | (0018,0060) | 1 | Exact peak kilo voltage output of the X-Ray generator used for this frame.
>X-Ray Tube Current in mA | (0018,9330) | 1 | Exact Nominal X-Ray tube current in milliamperes applied during Acquisition Duration (0018,9220) for this frame.

###### C.8.19.6.8.1 X-Ray Frame Acquisition Sequence Attributes

These attribute may only be used if the information is available on a frame-by-frame base. The average values for these attributes of all frames shall be stored in the same attribute in the XA/XRF Acquisition Module (Section C.8.19.3).

##### C.8.19.6.9 X-Ray Projection Pixel Calibration Macro

Table C.8.19.6-9 specifies the attributes of the X-Ray Projection Pixel Calibration Functional Group Macro.

Table C.8.19.6-9. X-Ray Projection Pixel Calibration Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Projection Pixel Calibration Sequence | (0018,9401) | 1 | A sequence that describes the geometrical position of the patient relative to the equipment. Only a single Item shall be included in this sequence.
>Distance Object to Table Top | (0018,9403) | 2 | Distance between the anatomic region of interest of observation and table top in mm. ### Note This value is always positive, the object is assumed to be above the table. The value of this attribute is depending on the patient position on the tabletop (supine, left or right decubitus, etc.)
>Object Pixel Spacing in Center of Beam | (0018,9404) | 1C | Physical distance within the anatomic region of interest in the center of the beam and perpendicular to the beam between the center of each pixel, specified by a numeric pair adjacent row spacing (delimiter) adjacent column spacing in mm. See Section C.8.19.6.9.2. See Section 10.7.1.3 for further explanation of the value order. Required if Distance Object to Table Top (0018,9403) is not empty. ### Note This value is provided besides the values that are the input parameters of the calibration algorithm.
>Table Height | (0018,1130) | 1C | The distance of the top of the patient table to the center of rotation of the source (i.e., the isocenter) in mm. A positive value indicates that the tabletop is below the isocenter. ### Note All the distances are measured perpendicular to the Table Top plane. Required if Image Type (0008,0008) Value 1 is ORIGINAL, may be present otherwise.
>Beam Angle | (0018,9449) | 1C | The equipment related angle in degrees of the X-Ray beam relative to the perpendicular to the tabletop plane. An angle from 0 to +90 degrees indicates that the X-Ray source is below the table. The valid range is 0 to +180 degrees. Required if Image Type (0008,0008) Value 1 is ORIGINAL, may be present otherwise.

###### C.8.19.6.9.1 Projection Calibration Method

The X-Ray Projection Pixel Calibration Macro defines the attributes needed to completely describe the specific inputs and results from projection image pixel calibration based on isocenter reference. The attributes are provided to allow usage of calibration result as well as recalibration. Figure C.8.19.6-1 and Figure C.8.19.6-2 illustrate the relationship of the attributes.

In Figure C.8.19.6-1 and Figure C.8.19.6-2, the object of interest of size D (in mm) is projected on the stored image over a distance of #Px (in pixels). The pixel spacing on the stored image is called DPx. The "Source to Isocenter Distance" is called ISO. The "Source Image Receptor Distance" is called SID. The shortest distance from the tabletop plane to the Isocenter and to the object of interest are called respectively TH and TO. The angle between the X-Ray beam and the axis perpendicular to the tabletop plane is called Beam Angle. Finally, the distance from the X-Ray source to the object of interest in the direction of the X-Ray beam is called SOD and is calculated from the other distances.

DPx: Imager Pixel Spacing (0018,1164)

ISO: Source Isocenter Distance (0018,9402)

SID: Distance Source to Detector (0018,1110)

TH: Table Height (0018,1130)

TO: Distance Object to Table Top (0018,9403)

Beam Angle: Beam Angle (0018,9449)

### Note

The equipment related Beam Angle attribute (0018,9449) shall be consistent with the patient oriented Positioner Primary Angle (0018,1510) and Positioner Secondary Angle (0018,1511) together with the patient orientation on the table specified in Patient Orientation Code Sequence (0054,0410) attributes.

Figure C.8.19.6-1 and Figure C.8.19.6-2 illustrate the usage of the attributes under the conditions laid out above.

Figure C.8.19.6-1. Project Calibration Without Angulation of the X-Ray Beam (Beam Angle = 0)

Figure C.8.19.6-2. Project Calibration With Angulation of the X-Ray Beam (Beam Angle Not Equal to 0)

###### C.8.19.6.9.2 Object Pixel Spacing in Center of Beam

The value provided for Beam Angle (0018,9449) shall correspond to the other attribute values within this module and according to the mathematic terms listed in Section C.8.19.6.9.1.

The terms listed will result in infinite result when used with 90-degree beam angles.

It is outside the scope of this Standard to define reasonable limits for single input values in the above-mentioned terms, or to define the mathematical accuracy of applications using those terms.

### Note

It may be reasonable to limit automatic calculations to a narrow range of +/- 60 degrees for Beam Angle and inform users about possible deviations in the calibration result when exceeding such range limits.

##### C.8.19.6.10 X-Ray Positioner Macro

Table C.8.19.6-10 specifies the attributes of the X-Ray Positioner Functional Group Macro. If included into the Shared Functional Groups Sequence (5200,9229) no DYNAMIC motion was performed during acquisition. If included in the Per-frame Functional Groups Sequence (5200,9230) the indication of a DYNAMIC motion is given.

Table C.8.19.6-10. X-Ray Positioner Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Positioner Position Sequence | (0018,9405) | 1 | A sequence that describes the geometrical position of the positioner. Only a single Item shall be included in this sequence.
>Positioner Primary Angle | (0018,1510) | 1C | Position of the X-Ray Image Intensifier about the patient from the RAO to LAO direction where movement from RAO to vertical is positive. See Section C.8.7.5.1.2. Required if Positioner Type (0018,1508) equals CARM.
>Positioner Secondary Angle | (0018,1511) | 1C | Position of the X-Ray Image Intensifier about the patient from the CAU to CRA direction where movement from CAU to vertical is positive. See Section C.8.7.5.1.2 Required if Positioner Type (0018,1508) equals CARM.
>Column Angulation (Patient) | (0018,9447) | 1C | Angle of the X-Ray beam in degree relative to an orthogonal axis to the detector plane. Positive values indicate that the tilt is towards the head of the patient. ### Note The detector plane is assumed to be parallel to the table plane This attribute differentiates form the attribute Column Angulation (0018,1450) by using the patient based coordinate system instead of the equipment based coordinate system. Required if Positioner Type (0018,1508) equals COLUMN.

##### C.8.19.6.11 X-Ray Table Position Macro

Table C.8.19.6-11 specifies the attributes of the X-Ray Table Position Functional Group Macro.

Table C.8.19.6-11. X-Ray Table Position Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Table Position Sequence | (0018,9406) | 1 | A sequence that describes the geometrical position of the table top. Only a single Item shall be included in this sequence.
>Table Top Vertical Position | (300A,0128) | 1 | Table Top Vertical position with respect to an arbitrary chosen reference by the equipment in (mm). Table motion downwards is positive
>Table Top Longitudinal Position | (300A,0129) | 1 | Table Top Longitudinal position with respect to an arbitrary chosen reference by the equipment in (mm). Table motion towards LAO is positive assuming that the patient is positioned supine and its head is in normal position.
>Table Top Lateral Position | (300A,012A) | 1 | Table Top Lateral position with respect to an arbitrary chosen reference by the equipment in (mm). Table motion towards CRA is positive assuming that the patient is positioned supine and its head is in normal position.
>Table Horizontal Rotation Angle | (0018,9469) | 1 | Rotation of the table in the horizontal plane (clockwise when looking from above the table).
>Table Head Tilt Angle | (0018,9470) | 1 | Angle of the head-feet axis of the table in degrees relative to the horizontal plane. Positive values indicate that the head of the table is upwards.
>Table Cradle Tilt Angle | (0018,9471) | 1 | Angle of the left-right axis of the table in degrees relative to the horizontal plane. Positive values indicate that the left of the table is upwards.

###### C.8.19.6.11.1 X-Ray Table Position Macro Attribute Description

The Table Top Position attributes of the Table Position Sequence (0018,9406) specify the geometrical position of the Table in the three spatial directions (i.e., Vertical, Longitudinal and Lateral) relative to the Table Top plane (see Figure C.8.19.6-3). The absolute reference point to which the Table positions are related is arbitrarily defined by the manufacturer.

The Table Angle attributes of the Table Position Sequence (0018,9406) specify the rotation and tilt of the Table Top Plane with respect to a plane arbitrarily defined by the manufacturer (usually the horizontal plane).

The Table Top Position attributes allow to describe the incremental translation of the Table top between frames of the same Multi-frame image, and between frames of different images, provided that the Table Angles are not modified between these frames.

When the table angles are modified between two frames, the Table Position Sequence (0018,9406) does not allow to characterize the relationship between the two table positions in an absolute reference coordinate system. For this purpose, the X-Ray Isocenter Reference System Macro has to be used.

### Note

The incremental table translation may be used, in conjunction with the Positioner Position Sequence attributes (0018,9405), for simple 2D-2D registration applications (object tracking, pixel shift…), assuming that the patient position is fixed on the table. For more complex registration applications, and in order to properly handle the changes in the table angles, it is recommended to use the X-Ray Isocenter Reference System Macro attributes.

Figure C.8.19.6-3. Table Position Vectors

##### C.8.19.6.12 X-Ray Collimator Macro

Table C.8.19.6-12 specifies the attributes of the X-Ray Collimator Functional Group Macro.

Table C.8.19.6-12. X-Ray Collimator Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Collimator Shape Sequence | (0018,9407) | 1 | A sequence that describes the collimator shape. Only a single Item shall be included in this sequence.
>Collimator Shape | (0018,1700) | 1 | Shape(s) of the collimator. Enumerated Values: RECTANGULAR CIRCULAR POLYGONAL This multi-valued Attribute shall contain at most one of each Enumerated Value.
>Collimator Left Vertical Edge | (0018,1702) | 1C | Required if Collimator Shape (0018,1700) is RECTANGULAR. Location of the left edge of the rectangular collimator expressed as effective pixel column. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Collimator Right Vertical Edge | (0018,1704) | 1C | Required if Collimator Shape (0018,1700) is RECTANGULAR. Location of the right edge of the rectangular collimator expressed as effective pixel column. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Collimator Upper Horizontal Edge | (0018,1706) | 1C | Required if Collimator Shape (0018,1700) is RECTANGULAR. Location of the upper edge of the rectangular collimator expressed as effective pixel row. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Collimator Lower Horizontal Edge | (0018,1708) | 1C | Required if Collimator Shape (0018,1700) is RECTANGULAR. Location of the lower edge of the rectangular collimator expressed as effective pixel row. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Center of Circular Collimator | (0018,1710) | 1C | Required if Collimator Shape (0018,1700) is CIRCULAR. Location of the center of the circular collimator expressed as effective pixel row and column. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Radius of Circular Collimator | (0018,1712) | 1C | Required if Collimator Shape (0018,1700) is CIRCULAR. Radius of the circular collimator expressed as effective number of pixels along the row direction. See Section C.8.7.3.1.1 and Section C.8.19.6.12.1.
>Vertices of the Polygonal Collimator | (0018,1720) | 1C | Required if Collimator Shape (0018,1700) is POLYGONAL. Multiple Values where the first set of two values are: row of the origin vertex; column of the origin vertex. Two or more pairs of values follow and are the effective pixel row and column coordinates of the other vertices of the polygon collimator. Polygon collimators are implicitly closed from the last vertex to the origin vertex and all edges shall be non-intersecting except at the vertices. See Section C.8.19.6.12.1.

###### C.8.19.6.12.1 X-Ray Collimator Attributes

The top left pixel of the image has a pixel row and column value of 1.

##### C.8.19.6.13 X-Ray Isocenter Reference System Macro

Table C.8.19.6-13 specifies the attributes of the X-Ray Isocenter Reference System Functional Group Macro.

Table C.8.19.6-13. X-Ray Isocenter Reference System Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Isocenter Reference System Sequence | (0018,9462) | 1 | A sequence that describes the Isocenter Reference Coordinate System (O, X, Y, Z). Only a single Item shall be included in this sequence.
>Positioner Isocenter Primary Angle | (0018,9463) | 1 | Position of the X-Ray center beam in the isocenter reference system in the X direction (deg). See Section C.8.19.6.13.1.2 for further explanation.
>Positioner Isocenter Secondary Angle | (0018,9464) | 1 | Position of the X-Ray center beam in the isocenter reference system in the Z direction (deg). See Section C.8.19.6.13.1.2 for further explanation.
>Positioner Isocenter Detector Rotation Angle | (0018,9465) | 1 | Rotation of the X-Ray detector plane (deg). See Section C.8.19.6.13.1.2 for further explanation.
>Table X Position to Isocenter | (0018,9466) | 1 | X position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Y Position to Isocenter | (0018,9467) | 1 | Y position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Z Position to Isocenter | (0018,9468) | 1 | Z position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Horizontal Rotation Angle | (0018,9469) | 1 | Rotation of the table in the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.
>Table Head Tilt Angle | (0018,9470) | 1 | Angle of the head-feet axis of the table in degrees relative to the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.
>Table Cradle Tilt Angle | (0018,9471) | 1 | Angle of the left-right axis of the table in degrees relative to the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.

###### C.8.19.6.13.1 Isocenter Reference System Attribute Description

The Isocenter Reference System Attributes describe the 3D geometry of the X-Ray equipment composed by the X-Ray positioner and the X-Ray table.

These attributes define three coordinate systems in the 3D space:

- Isocenter coordinate system

- Positioner coordinate system

- Table coordinate system

The Isocenter Reference System attributes describe the relationship between the 3D coordinates of a point in the table coordinate system and the 3D coordinates of such point in the positioner coordinate system (both systems moving in the equipment), by using the Isocenter coordinate system that is fixed in the equipment.

### Note

Annex FFF “Enhanced XA/XRF Encoding Examples (Informative)” in PS3.17 describes the transformations necessary to transpose between coordinate systems.

###### C.8.19.6.13.1.1 Isocenter Coordinate System

The Isocenter coordinate system (O,X,Y,Z) of the equipment is defined as follows:

- Origin O is on the System Isocenter

- +Y DOWNWARD (gravity)

- +X, +Z directions in the horizontal plane (gravity plane). Directions arbitrarily defined by the manufacturer

Figure C.8.19.6-4. Isocenter Coordinate System

###### C.8.19.6.13.1.2 Positioner Coordinate System

The Positioner Coordinate System (Op, Xp, Yp, Zp) is defined as follows:

- Origin Op, is the origin of the Isocenter coordinate system O

- Xp axis is parallel to the horizontal scan-lines of the detector (rows). Positive direction from left to right of the detector plane looking towards the source.

- Zp axis is parallel to the vertical scan-lines of the detector (columns). Positive direction from bottom to top of the detector plane looking towards the source.

- Yp is the axis from the isocenter to the X-Ray source. Positive direction from the Isocenter to the X-Ray Source. This axis is so-called the X-Ray center beam.

Figure C.8.19.6-5. Positioner Coordinate System

### Note

The quantities SID and ISO are specified by the attributes Distance Source to Detector (0018,1110) and Distance Source to Isocenter (0018,9402) respectively.

The Positioner Coordinate System (Op, Xp, Yp, Zp) is characterized, with respect to the Isocenter Coordinate System (O, X, Y, Z), by two angles describing the X-Ray center beam, and a third angle describing the rotation of the X-Ray detector plane. These angles are relative to the Isocenter reference system, and independent from the patient position on the equipment.

Positioner Isocenter Primary Angle (0018,9463) (so-called Ap1 in Figure C.8.19.6-6) is defined in the plane XY, as the angle between the plane YZ and the plane YpZ. The axis of rotation of this angle is the Z axis. Angle from -Y to +X is positive. The valid range of this angle is -180 to +180 degrees.

Positioner Isocenter Secondary Angle (0018,9464) (so-called Ap2 in Figure C.8.19.6-6) is defined in the plane YpZ, as the angle of the X-Ray Center Beam (i.e., Yp) relative to the XY plane. The axis of rotation of this angle is perpendicular to the plane YpZ. Angle from the plane XY to +Z is positive. The valid range of this angle is -180 to +180 degrees.

Positioner Isocenter Detector Rotation Angle (0018,9465) (so-called Ap3 in Figure C.8.19.6-6 and in Figure C.8.19.6-7) is defined in the detector plane, as the angle of the vertical scan-lines of the detector (i.e., Zp) relative to the intersection between the detector plane and the plane YpZ. The sign of this angle is positive clockwise when facing on to the detector plane (see Figure C.8.19.6-7). The valid range of this angle is -180 to +180 degrees.

Figure C.8.19.6-6. Positioner Isocenter Angles

Figure C.8.19.6-7. Positioner Isocenter Detector Rotation Angle when Ap1 = 0 and Ap2 = 0

###### C.8.19.6.13.1.3 Table Coordinate System

The table coordinate system (Ot, Xt, Yt, Zt) is defined as follows:

- Origin Ot, so-called Table Reference Point, is on the Table Top plane

- +Xt direction to the TABLE LEFT

- +Zt direction to the TABLE HEAD

- +Yt direction to the TABLE DOWN

The table coordinate system (Ot, Xt, Yt, Zt) is characterized, with respect to the Isocenter coordinate system (O, X, Y, Z), by a 3D translation and 3 angles describing the tilting and rotation:

Table X Position to Isocenter (0018,9466) (so-called TX in Figure C.8.19.6-8) is defined as the translation of the Table Reference Point Ot with respect to the Isocenter Coordinate System in the X direction. Table motion toward +X is positive.

Table Y Position to Isocenter (0018,9467) (so-called TY in Figure C.8.19.6-8) is defined as the translation of the Table Reference Point Ot with respect to the Isocenter Coordinate System in the Y direction. Table motion toward +Y is positive.

Table Z Position to Isocenter (0018,9468) (so-called TZ in Figure C.8.19.6-8) is defined as the translation of the Table Reference Point Ot with respect to the Isocenter Coordinate System in the Z direction. Table motion toward +Z is positive.

### Note

A translation of ( TX,TY,TZ ) = (0, 0, 0) means that the Table Reference Point Ot is at the System Isocenter.

Table Horizontal Rotation Angle (so-called At1 in Figure C.8.19.6-9) is defined in the horizontal plane XZ, as the angle of the projection of the +Zt axis in the XZ plane relative to the +Z axis. The axis of rotation of this angle is the vertical axis crossing the Table Reference Point Ot. Zero value is defined when the projection of +Zt in the XZ plane is equal to +Z. Angle from +Z to +X is positive. The valid range of this angle is -180 to +180 degrees.

Table Head Tilt Angle (so-called At2 in Figure C.8.19.6-9) is defined in the vertical plane containing Zt (i.e., YZt), as the angle of the +Zt axis relative to the horizontal plane XZ. The axis of rotation of this angle is defined as the intersection between the horizontal plane XZ and the plane XtYt. Zero value is defined when +Zt is contained in the horizontal plane XZ. Angle from horizontal (plane XZ) to -Y direction (upwards) is positive,indicating that the head of the table is above the horizontal plane. The valid range of this angle is -45 to +45 degrees.

Table Cradle Tilt Angle (so-called At3 in Figure C.8.19.6-9) is defined in the XtYt plane, as the angle of the +Xt axis relative to the intersection between the XtYt plane and the horizontal plane XZ. The axis of rotation of this angle is the axis Zt. Zero value is defined when +Xt is contained in the horizontal plane XZ. Angle from horizontal (plane XZ) to -Y direction (upwards) is positive,indicating that the left of the table is above the horizontal plane. The valid range of this angle is -45 to +45 degrees.

### Note

The angles At1 , At2 and At3 are independent from any specific mechanical design of the table rotation axis defined by a manufacturer. In particular, they don't require the three rotation axis to cross on a single point. If a mechanical rotation axis does not cross the Table Reference Point Ot, a mechanical rotation around this axis will generate a change in one or more table angles as well as a translation of the Table Reference Point.

Figure C.8.19.6-8. Table Translation with respect to the Isocenter Reference System

Figure C.8.19.6-9. Table Angulations with respect to the Isocenter Reference System

###### C.8.19.6.13.2 Relationship Patient Coordinate System

The Isocenter Reference System attributes allow expressing the positioner angulations (i.e., X-Ray Center Beam direction) as a vector in the table coordinate system. If the relationship between the X-Ray table and the patient is known, it is possible to express any vector of the table coordinate system as a direction in the patient.

Therefore, the Isocenter Reference System attributes allow calculating the positioner angulations in the patient-based coordinate system if the following attributes are present:

- Patient Orientation Code Sequence (0054,0410)

- Patient Orientation Modifier Code Sequence (0054,0412)

Further, the Isocenter Reference System attributes allow calculating the patient anatomical directions (i.e., left, right, head, feet, anterior, posterior) of the rows and columns of the stored image, if the following attributes are present:

- Patient Orientation Code Sequence (0054,0410)

- Patient Orientation Modifier Code Sequence (0054,0412)

- Field of View Rotation (0018,7032)

- Field of View Horizontal Flip (0018,7034)

For registration purposes, a given point fixed in the patient (object of interest) that is defined in the table coordinate system can be expressed as row and column coordinates of the stored image if the relationship between the positioner coordinate system and the stored image is fully characterized. Therefore, the Isocenter Reference System attributes allow calculating the projection of a point of the patient as row and column coordinates of the stored image, if the following attributes are present:

- Frame of Reference UID (0020,0052) and must be equal for all images involved in the registration

- Field of View Rotation (0018,7032)

- Field of View Horizontal Flip (0018,7034)

- Imager Pixel Spacing (0018,1164)

- Distance Source to Isocenter (0018,9402)

- Distance Source to Detector (0018,1110)

In addition for a system equipped with a digit al detector the following attributes need to be present:

- Detector Element Spacing (0018,7022)

- Field of view Origin (0018,7030)

- Position of Isocenter Projection (0018,9430)

##### C.8.19.6.14 X-Ray Geometry Macro

Table C.8.19.6-14 specifies the attributes containing the X-Ray Geometry Functional Group Macro.

Table C.8.19.6-14. X-Ray Geometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray Geometry Sequence | (0018,9476) | 1 | Sequence containing the geometric properties for this frame. Only a single Item shall be included in this sequence.
>Distance Source to Isocenter | (0018,9402) | 1 | Distance from source to isocenter in mm.
>Distance Source to Detector | (0018,1110) | 1 | Distance from source to receptor plane perpendicular to the receptor plane in mm. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).

#### C.8.19.7 XA/XRF Multi-frame Presentation Module

Table C.8.19.7-1 specifies the Attributes of a XA/XRF Multi-frame Presentation Module.

Table C.8.19.7-1. XA/XRF Multi-frame Presentation Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Preferred Playback Sequencing | (0018,1244) | 3 | Describes the preferred playback sequencing for a multi-frame image. Enumerated Values: 0 Looping (1,2…n,1,2,…n,1,2,….n,…) 1 Sweeping (1,2,…n,n -1,…2,1,2,…n,…)
Frame Display Sequence | (0008,9458) | 3 | Sequence that specifies the display frame rate of a selected set of frames. The Items are ordered in increasing frame number. The range of the frames may not overlap and the ranges shall be adjacent. One or more items are permitted in this sequence.
>Start Trim | (0008,2142) | 1 | The Frame Number of the first frame of the set of frames to be displayed in this Item.
>Stop Trim | (0008,2143) | 1 | The Frame Number of the last frame of the set of frames to be displayed in this Item.
>Skip Frame Range Flag | (0008,9460) | 1 | A flag indicating that the range of frames in this item may be skipped. Defined Terms: DISPLAY SKIP
>Recommended Display Frame Rate in Float | (0008,9459) | 1 | Recommended rate at which the frames of this Item should be displayed in frames/second.
>Recommended Viewing Mode | (0028,1090) | 2 | Specifies the recommended viewing protocol(s). When this attribute is present with a value, this value shall override the value of Recommended Viewing Mode (0028,1090) specified in the Mask Module. Defined Terms: SUB subtraction with mask images NAT native viewing of image as stored ### Note If an implementation does not recognize the Defined Term for Recommended Viewing Mode (0028,1090), reverting to native display mode is recommended.
>Display Filter Percentage | (0028,9411) | 2 | Edge enhancement filter percentage that is recommended by the pixel data creator as filter presetting for display purposes. The value of 100 corresponds to the maximum filter strength that can be applied by a specific application displaying the image.
>Mask Visibility Percentage | (0028,9478) | 1C | The percentage of visibility of the mask frame during a subtracted display. A value of 0 corresponds to subtracted display, a value of 100 corresponds to un-subtracted display (native). See Section C.8.19.7.1. ### Note The value of 100 is equivalent to Recommended Viewing Mode (0028,1090) having a value of NAT. Required if Recommended Viewing Mode (0028,1090) equals SUB.

##### C.8.19.7.1 Multi-frame Presentation Attributes

###### C.8.19.7.1.1 Mask Visibility Percentage (Informative)

An example of the usage of the Mask Visibility Percentage (0028,9478) attribute is illustrated below.

Assume that Psub is the output pixel level of a subtracted frame,its calculation can be expressed as followed:

Pcontrast: Pixel level of the contrast frame in the logarithmic domain

Pmask: Pixel level of the mask frame in the logarithmic domain

X: Mask Visibility Percentage (0028,9478): 0 <= X <= 100

Psub = Pcontrast- (1- X/100) * Pmask

### C.8.20 Segmentation

This section describes the specific modules for the Segmentation IOD.

#### C.8.20.1 Segmentation Series Module

Table C.8.20-1 defines the general Attributes of the Segmentation Series Module.

Table C.8.20-1. Segmentation Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Modality Type Enumerated Values: SEG
Series Number | (0020,0011) | 1 | A number that identifies this Series
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.20.2 Segmentation Image Module

Table C.8.20-2 defines the general Attributes of the Segmentation Image Module.

Table C.8.20-2. Segmentation Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Value 1 shall be DERIVED. Value 2 shall be PRIMARY. No other values shall be present.
Include Table 10-12 “Content Identification Macro Attributes” |
Samples Per Pixel | (0028,0002) | 1 | Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Enumerated Values: MONOCHROME2
Pixel Representation | (0028,0103) | 1 | Enumerated Values: 0
Bits Allocated | (0028,0100) | 1 | See Section C.8.20.2.1. Enumerated Values if Segmentation Type (0062,0001) is BINARY: 1 Enumerated Values if Segmentation Type (0062,0001) is not BINARY: 8
Bits Stored | (0028,0101) | 1 | See Section C.8.20.2.1. Enumerated Values if Segmentation Type (0062,0001) is BINARY: 1 Enumerated Values if Segmentation Type (0062,0001) is not BINARY: 8
High Bit | (0028,0102) | 1 | See Section C.8.20.2.1. Enumerated Values if Segmentation Type (0062,0001) is BINARY: 0 Enumerated Values if Segmentation Type (0062,0001) is not BINARY: 7
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime), or is derived from lossy compressed images. Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.8.20.2.2 and Section C.7.6.1.1.5, “Lossy Image Compression”.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if present in the source images or this IOD instance has been compressed.
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if present in the source images or this IOD instance has been compressed. See Section C.8.20.2.2.
Segmentation Type | (0062,0001) | 1 | The type of encoding used to indicate the presence of the segmented property at a pixel/voxel location. Enumerated Values: BINARY FRACTIONAL See Section C.8.20.2.3.
Segmentation Fractional Type | (0062,0010) | 1C | For fractional segmentation encoding, the meaning of the fractional value. Required if Segmentation Type (0062,0001) is FRACTIONAL. See Section C.8.20.2.3 for Enumerated Values.
Maximum Fractional Value | (0062,000E) | 1C | Specifies the value that represents 100%. There shall be no values in Pixel Data (7FE0,0010) greater than this value. Required if Segmentation Type (0062,0001) is FRACTIONAL.
Segment Sequence | (0062,0002) | 1 | Describes the segments that are contained within the data. One or more Items shall be included in this sequence.
>Include Table C.8.20-4 “Segment Description Macro Attributes” |
>Segment Algorithm Name | (0062,0009) | 1C | Name of algorithm used to generate the segment. Required if Segment Algorithm Type (0062,0008) is not MANUAL.
>Segment Surface Generation Algorithm Identification Sequence | (0066,002D) | 3 | A description of how this segment was derived. Only a single item is permitted in this sequence.
>>Include Table 10-19 “Algorithm Identification Macro Attributes” | Baseline CID 7162 “Surface Processing Algorithm Families”.
>Recommended Display Grayscale Value | (0062,000C) | 3 | A default single gray unsigned value in which it is recommended that the maximum pixel value in this segment be rendered on a monochrome display. The units are specified in P-Values from a minimum of 0000H (black) up to a maximum of FFFFH (white). ### Note The maximum P-Value for this Attribute may be different from the maximum P-Value from the output of the Presentation LUT, which may be less than 16 bits in depth.
>Recommended Display CIELab Value | (0062,000D) | 3 | A default triplet value in which it is recommended that segment be rendered on a color display. The units are specified in PCS-Values, and the value is encoded as CIELab. See Section C.10.7.1.1.

##### C.8.20.2.1 Bits Allocated and Bits Stored

As a consequence of the enumerated Bits Allocated and Bits Stored attribute values, single bit pixels shall be packed 8 to a byte as defined by the encoding rules in PS3.5.

##### C.8.20.2.2 Lossy Image Compression and Lossy Image Compression Method

If Lossy Image Compression (0028,2110) in any of the source images is "01", the value shall be "01" for the Segmentation instance.

The process of segmentation itself is defined not to be lossy compression, even though it involves loss. If the Segmentation instance is encoded using a lossy compression transfer syntax, then the value shall be set to "01".

### Note

It is not advisable to lossy compress a Segmentation SOP Instance. In particular, a binary segmentation should not be lossy compressed.

##### C.8.20.2.3 Segmentation Type and Segmentation Fractional Type

A Segmentation Type (0062,0001) of BINARY indicates the segmented property is present with a value of 1 and absent with a value of 0.

For a Segmentation Type (0062,0001) of FRACTIONAL the segmented property is defined as a value from zero to the Maximum Fractional Value (0062,000E). A FRACTIONAL segmentation shall be further specified via Segmentation Fractional Type (0062,0010).

Enumerated Values of Segmentation Fractional Type (0062,0010):

PROBABILITY

  Defines the probability, as a percentage, that the segmented property occupies the spatial area defined by the voxel.

OCCUPANCY

  Defines the percentage of the voxel area occupied by the segmented property.

##### C.8.20.2.4 Segment Number

Segment Number (0062,0004) shall be unique within each instance, start at a value of 1, and increase monotonically by 1.

#### C.8.20.3 Segmentation Functional Group Macros

The following sections contain Functional Group Macros specific to the Segmentation IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean "for all frames".

##### C.8.20.3.1 Segmentation Macro

Table C.8.20-3 specifies the attributes of the Segmentation Functional Group Macro.

Table C.8.20-3. Segmentation Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Segment Identification Sequence | (0062,000A) | 1 | Identifies the characteristics of this frame. Only a single Item shall be included in this sequence.
>Referenced Segment Number | (0062,000B) | 1 | Uniquely identifies the segment described in Segment Sequence (0062,0002) by reference to Segment Number (0062,0004). Referenced Segment Number (0062,000B) shall not be multi-valued.

#### C.8.20.4 Segmentation Macros

The following sections contain macros specific to the Segmentation IOD.

##### C.8.20.4.1 Segment Description Macro

Table C.8.20-4 specifies the attributes of the Segment Description Macro.

Table C.8.20-4. Segment Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Segment Number | (0062,0004) | 1 | Identification number of the segment. The value of Segment Number (0062,0004) shall be unique within the Segmentation instance in which it is created. See Section C.8.20.2.4.
Segment Label | (0062,0005) | 1 | User-defined label identifying this segment. This may be the same as Code Meaning (0008,0104) of Segmented Property Type Code Sequence (0062,000F).
Segment Description | (0062,0006) | 3 | User-defined description for this segment.
Segment Algorithm Type | (0062,0008) | 1 | Type of algorithm used to generate the segment. Enumerated Values: AUTOMATIC calculated segment SEMIAUTOMATIC calculated segment with user assistance MANUAL user-entered segment
Include Table 10-7 “General Anatomy Optional Macro Attributes” | May be not be necessary if the anatomy is implicit in the Segmented Property Type Code Sequence.
Segmented Property Category Code Sequence | (0062,0003) | 1 | Sequence defining the general category of this segment. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 7150 “Segmentation Property Categories”.
Segmented Property Type Code Sequence | (0062,000F) | 1 | Sequence defining the specific property type of this segment. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 7151 “Segmentation Property Types”.
>Segmented Property Type Modifier Code Sequence | (0062,0011) | 3 | Sequence defining the modifier of the property type of this segment. One or more Items are permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 244 “Laterality”.

### C.8.21 X-Ray 3D

#### C.8.21.1 X-Ray 3D Image Module

This section describes the X-Ray 3D Image Module. Table C.8.21.1-1 contains IOD Attributes that describe a X-Ray 3D Image by specializing Attributes of the General Image and Image Pixel Modules, and adding additional Attributes.

Table C.8.21.1-1. X-Ray 3D Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.21.1.1.1 for specialization.
Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each voxel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each voxel sample. Each sample shall have the same number of bits stored. Enumerated Values: 8 9 10 11 12 13 14 15 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Samples per Pixel | (0028,0002) | 1 | Number of samples (color planes) in this image shall have a value of 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the voxel data. Enumerated Values: MONOCHROME2
Content Qualification | (0018,9004) | 1 | Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See Section C.8.13.2.1.1 for further explanation.
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not the image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Referenced Image Evidence Sequence | (0008,9092) | 1C | Full set of Composite SOP Instances referred to inside the Referenced Image Sequences of this SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Image Comments | (0020,4000) | 3 | User-defined comments about the image.
Quality Control Image | (0028,0300) | 3 | Indicates whether or not this image is a quality control or phantom image. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not be a quality control or phantom image.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6 for further explanation.
Presentation LUT Shape | (2050,0020) | 1 | Specifies a predefined identity transformation for the Presentation LUT such that the output of all grayscale transformations, if any, are defined to be in P-Values. Enumerated Values: IDENTITY output is in P-Values
Source Irradiation Event Sequence | (0008,3011) | 3 | The set of Irradiation Events that were produced in this acquisition context. See C.8.21.1.1.4. One or more Items shall be included in this Sequence.
>Irradiation Event UID | (0008,3010) | 1 | Unique identification of the irradiation event(s) associated with the acquisition of this image.

##### C.8.21.1.1 X-Ray 3D Image Module Attribute Description

###### C.8.21.1.1.1 Image Type and Frame Type

In addition to the requirements specified in Section C.8.16.1 Image Type, the following additional requirements and Defined Terms are specified.

###### C.8.21.1.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.21.1.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.21.1.1.1.3 Image Flavor

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.3. No additional requirements or Defined Terms.

###### C.8.21.1.1.1.4 Derived Pixel Contrast

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.4. The value shall be NONE.

###### C.8.21.1.1.2 Volumetric Properties Attribute

The value of Volumetric Properties (0008,9206) is discussed in Section C.8.16.2.1.2.

### Note

1. For regularly sampled tomosynthesis slices reconstructed from projection X-Ray data, a value of VOLUME or SAMPLED is appropriate.

2. For slabs constructed by averaging adjacent regularly sampled tomosynthesis slices to produce thicker slices, a value of SAMPLED is appropriate.

3. For mathematically generated 2D views (e.g., constructed as Maximum Intensity Projections) of regularly sampled tomosynthesis slices, a value of SAMPLED is appropriate.

###### C.8.21.1.1.3 Volume Based Calculation Technique Attribute

The value of Volume Based Calculation Technique (0008,9207) is discussed in Section C.8.16.2.1.3.

Table C.8.21.1.1.3-1 specifies the additional Defined Terms for the Volume Based Calculation Technique (0008,9207) attribute to those in Table C.8-134 in Section C.8.16.2.1.3.

Table C.8.21.1.1.3-1. Additional Volume Based Calculation Technique Attribute Values for X-Ray 3D

Defined Term Name | Defined Term Description
--- | ---
TOMOSYNTHESIS | Construction of tomographic slices or slabs from limited angle projection data.

### Note

1. For tomosynthesis slices or slabs reconstructed from projection X-Ray data, a value of TOMOSYNTHESIS is appropriate.

2. For mathematically generated 2D views constructed as Maximum Intensity Projections of tomosynthesis slices, a value of MAX_IP is appropriate.

###### C.8.21.1.1.4 Source Irradiation Event Sequence

The Source Irradiation Event Sequence (0008,3011) contains the Irradiation Event UIDs of all the original projection images that were used in the 3D reconstruction process of this X-Ray 3D Image, regardless whether the projection images are encoded as DICOM images or not. Therefore, it allows relating the reconstructed X-Ray 3D image to its contributing irradiation events contained in the Radiation Dose SR.

The equipment generating the projection images associates these images to one or more Irradiation Event UIDs. All these UIDs are then included in the Radiation Dose SR as well as in the appropriate projection DICOM images. An X-Ray 3D image reconstructed from a set of projection images will include those Irradiation Event UIDs of the images that participated to that 3D reconstruction. In case the projection images are not encoded as DICOM images, the X-Ray equipment is responsible for including the contributing Irradiation Event UIDs in any further X-Ray 3D image reconstructed on that equipment.

An X-Ray 3D image derived from one or more X-Ray 3D images will include in the derived image all the Irradiation Event UIDs of the source images.

#### C.8.21.2 X-Ray 3D Contributing Image Sources Modules

This section describes the X-Ray 3D Image Contributing Sources Modules.

### Note

1. These modules supply general information of the sources without the need to have access to all the contributing SOP Instances or when these SOP Instances do not exist.

2. These modules do not contain specific information of the X-Ray acquisition itself. For this purpose the X-Ray 3D Acquisition Modules may be used.

##### C.8.21.2.1 X-Ray 3D Angiographic Image Contributing Sources Module

This section describes the X-Ray 3D Angiographic Image Contributing Sources Module. The attributes in this Module specify the overall characteristics of one or more sources that were used to create a X-Ray 3D Angiographic Image SOP Class instance. Table C.8.21.2.1-1 contains the relevant IOD Attributes that describe X-Ray 3D Angiographic Image Contributing Sources.

Table C.8.21.2.1-1. X-Ray 3D Angiographic Image Contributing Sources Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Contributing Sources Sequence | (0018,9506) | 1 | A sequence that describes characteristics of the sources that are used to create a derived SOP Instance. One or more Items shall be included in this sequence.
>Include Table 10-13 “General Contributing Sources Macro Attributes” |
>Include Table 10-14 “Contributing Image Sources Macro Attributes” |
>Acquisition Device Processing Description | (0018,1400) | 1C | Indicates any visual processing performed on the frame prior to exchange. See Section C.8.7.1.1.3. Required if present and consistent in the contributing SOP Instances.
>Acquisition Device Processing Code | (0018,1401) | 1C | Code representing the device-specific processing associated with the frame (e.g., Organ Filtering code) Required if present and have an equal value in the contributing SOP Instances.
>Plane Identification | (0018,9457) | 1C | Identification of the plane used to acquire this image. Defined Terms: MONOPLANE PLANE A PLANE B Required if present and consistent in the contributing SOP Instances.
>Imager Pixel Spacing | (0018,1164) | 1C | Physical distance measured at the receptor plane of the detector between the centers of each pixel specified by a numeric pair - row spacing value (delimiter) column spacing value in mm. Required if present and consistent in the contributing SOP Instances.

##### C.8.21.2.2 X-Ray 3D Craniofacial Image Contributing Sources Module

This section describes the X-Ray 3D Craniofacial Image Contributing Sources Module. The attributes in this Module specify the overall characteristics of one or more sources that were used to create a X-Ray 3D Craniofacial Image SOP Class instance. Table C.8.21.2.2-1 contains the relevant IOD Attributes that describe X-Ray 3D Craniofacial Image Contributing Sources.

Table C.8.21.2.2-1. X-Ray 3D Craniofacial Image Contributing Sources Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Contributing Sources Sequence | (0018,9506) | 1 | A sequence that describes characteristics of the sources that are used to create a derived SOP Instance. One or more Items shall be included in this sequence.
>Include Table 10-13 “General Contributing Sources Macro Attributes” |
>Include Table 10-14 “Contributing Image Sources Macro Attributes” |
>Acquisition Device Processing Description | (0018,1400) | 1C | Indicates any visual processing performed on the frame prior to exchange. See Section C.8.7.1.1.3. Required if present and consistent in the contributing SOP Instances.
>Acquisition Device Processing Code | (0018,1401) | 1C | Code representing the device-specific processing associated with the frame (e.g., Organ Filtering code). Required if present and have an equal value in the contributing SOP Instances.
>Imager Pixel Spacing | (0018,1164) | 1C | Physical distance measured at the receptor plane of the detector between the centers of each pixel specified by a numeric pair - row spacing value (delimiter) column spacing value in mm. Required if present and consistent in the contributing SOP Instances.

##### C.8.21.2.3 Breast Tomosynthesis Contributing Sources Module

This section describes the Breast Tomosynthesis Contributing Sources Module. The attributes in this Module specify the overall characteristics of one or more source images that were used to create a Breast Tomosynthesis Image SOP Class instance. Table C.8.21.2.3-1 contains the IOD Attributes that describe Breast Tomosynthesis Contributing Sources.

### Note

The intention of this module is to supply acquisition information without the need to have access to all the source projection images.

Table C.8.21.2.3-1. Breast Tomosynthesis Contributing Sources Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Contributing Sources Sequence | (0018,9506) | 1 | A sequence that describes characteristics of the sources that are used to create a derived SOP Instance. One or more Items shall be included in this sequence.
>Include Table 10-13 “General Contributing Sources Macro Attributes” |
>Include Table 10-14 “Contributing Image Sources Macro Attributes” |
>Detector Type | (0018,7004) | 1 | The type of detector used to acquire this image. Defined Terms: DIRECT X-Ray photoconductor SCINTILLATOR Phosphor used STORAGE Storage phosphor
>Detector ID | (0018,700A) | 1 | The ID or serial number of the detector used to acquire this image.
>Date of Last Detector Calibration | (0018,700C) | 1 | The date on which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated.
>Time of Last Detector Calibration | (0018,700E) | 1 | The time at which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated.
>Detector Element Spacing | (0018,7022) | 1 | Physical distance between the center of each detector element, specified by a numeric pair: row spacing value (delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. ### Note This may not be the same as the Imager Pixel Spacing (0018,1164), and should not be assumed to describe the stored image.

#### C.8.21.3 X-Ray 3D Acquisition Modules

This section describes the X-Ray 3D Acquisition Modules and Macros to specify the acquisition context information used as input for one or more reconstructions. The Macros in this section define the attributes that are common for all modalities. The Macros are used in the modality specific Modules.

The attributes of each item in the X-Ray 3D Acquisition Sequence (0018,9507) define the acquisition characteristics of the projection images that were used to create one or more reconstructions.

### Note

1. The intention of this sequence is to supply acquisition information without the need to have access to all the contributing SOP Instances or when these SOP Instances do not exist.

2. The number of frames referenced in this sequence is not necessarily the same as the number of projection images.

For each item of the X-Ray 3D Reconstruction Sequence (0018,9530) in the X-Ray 3D Reconstruction Module, the values of Acquisition Index (0020,9518) specify the items in the X-Ray 3D Acquisition Sequence (0018,9507) that contribute to the reconstruction.

### Note

For example, a SOP Instance consists of two volumes in two sets of frames. The first volume is calculated from an acquisition without contrast and a second volume is calculated from the acquisitions with and without contrast. In this case the X-Ray 3D Acquisition Sequence (0018,9507) contains two items. The first Item describes the acquisition details of the frames that are acquired without contrast. The second Item describes the acquisition details of the frames that are acquired with contrast. For the frames of the second volume both acquisitions contribute to the calculation. See Figure C.8.21.3-1, Figure C.8.21.3-2, Figure C.8.21.3-3, Figure C.8.21.3-4 and Figure C.8.21.3-5.

Figure C.8.21.3-1. Example of Usage Acquisition

Figure C.8.21.3-2. Example of Contents of Contributing Sources Sequence

Figure C.8.21.3-3. Example of Contents of X-Ray 3D Acquisition Sequence

Figure C.8.21.3-4. Example of Contents of X-Ray 3D Reconstruction Sequence

Figure C.8.21.3-5. Example of Contents of X-Ray 3D Frame Type Sequences

##### C.8.21.3.1 X-Ray 3D General Acquisition Macros

This section describes the X-Ray 3D General Acquisition Macros. These macros specify the attributes of the acquisition context common for the family of X-Ray 3D image SOP Classes.

###### C.8.21.3.1.1 X-Ray 3D General Shared Acquisition Macro

Table C.8.21.3.1.1-1 describes the X-Ray 3D General Shared Acquisition Macro that specifies the attributes that are applicable for all the projection images belonging to this acquisition context.

Table C.8.21.3.1.1-1. X-Ray 3D General Shared Acquisition Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Source Image Sequence | (0008,2112) | 1C | A Sequence that identifies the set of Images that constitute this acquisition context. Required if the reconstruction is created from DICOM SOP Instances. ### Note The attribute is absent in the case where the images used to create the volume are not available as SOP Instances, e.g., the volume was directly generated by acquisition system. One or more Items shall be included in this Sequence.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
Field of View Dimension(s) in Float | (0018,9461) | 1C | Dimensions in mm of the Field of View in the source projection images. If Field of View Shape (0018,1147) is: RECTANGLE: row dimension followed by column. ROUND: diameter. HEXAGONAL: diameter of the circle circumscribing the hexagon. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Field of View Origin | (0018,7030) | 1C | Offset of the TLHC of a rectangle circumscribing the Field of View in the referenced images, before rotation or flipping, from the TLHC of the physical detector area measured in physical detector pixels as a row offset followed by a column offset. See Section C.8.11.4.1.1 for further explanation. Required if X-Ray Receptor Type (0018,9420) is present and equals DIGITAL_DETECTOR.
Field of View Rotation | (0018,7032) | 1C | Clockwise rotation in degrees of Field of View in the referenced images, relative to the physical detector. Enumerated Values: 0 90 180 270 See Section C.8.11.4.1.1 for further explanation. Required if present and consistent in the contributing SOP Instances.
Field of View Horizontal Flip | (0018,7034) | 1C | Whether or not a horizontal flip has been applied to the Field of View in the referenced images, after rotation relative to the physical detector as described in Field of View Rotation (0018,7032). Enumerated Values: NO YES See Section C.8.11.4.1.1 for further explanation. Required if present and consistent in the contributing SOP Instances.
Grid | (0018,1166) | 1C | Identifies the grid. May be multi-valued. See Attribute Description in Section C.8.7.11 for Defined Terms. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Include Table C.8-36b “X-Ray Grid Description Macro Attributes” |
KVP | (0018,0060) | 1C | Average of the peak kilo voltage outputs of the X-Ray generator used for all frames. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
X-Ray Tube Current in mA | (0018,9330) | 1C | Average of the nominal X-Ray tube currents in milliamperes for all frames. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Exposure Time in ms | (0018,9328) | 1C | Total (cumulative) duration of X-Ray exposure for all frames in milliseconds. See Section C.8.7.2.1.1. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Exposure in mAs | (0018,9332) | 1C | The total (cumulative) exposure for all frames expressed in milliampereseconds, for example calculated from Exposure Time and X-Ray Tube Current. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Contrast/Bolus Agent | (0018,0010) | 1C | Contrast or bolus agent. Required if present and consistent in the contributing SOP Instances.
Contrast/Bolus Agent Sequence | (0018,0012) | 1C | Sequence that identifies the contrast agent. One or more Items shall be included in this sequence. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG and contrast media was applied.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 12 “Radiographic Contrast Agent”.
Start Acquisition DateTime | (0018,9516) | 1C | Start date and time of that part of an acquisition used for this acquisition context. Required if present and consistent in the contributing SOP Instances.
End Acquisition DateTime | (0018,9517) | 1C | End date and time of that part of an acquisition used for this acquisition context. Required if present and consistent in the contributing SOP Instances.

###### C.8.21.3.1.2 X-Ray 3D General Per Projection Acquisition Macro

Table C.8.21.3.1.2-1 describes the X-Ray 3D General Per Projection Acquisition Macro that specifies the attributes that are applicable for a single projection belonging to this acquisition context.

Table C.8.21.3.1.2-1. X-Ray 3D General Per Projection Acquisition Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
KVP | (0018,0060) | 1C | Exact peak kilo voltage output of the X-Ray generator used for this projection. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
X-Ray Tube Current in mA | (0018,9330) | 1C | Exact Nominal X-Ray tube current in milliamperes applied during the Frame Acquisition Duration (0018,9220) for this projection. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Frame Acquisition Duration | (0018,9220) | 1C | The actual amount of time [in milliseconds] that was used to acquire data for this projection. See Section C.7.6.16.2.2.1 and Section C.7.6.16.2.2.3 for further explanation. Required if present and consistent in the contributing SOP Instances.
Collimator Shape | (0018,1700) | 1C | Shape(s) of the collimator. Enumerated Values: RECTANGULAR CIRCULAR POLYGONAL This multi-valued Attribute shall contain at most one of each Enumerated Value. Required if present and consistent in the contributing SOP Instances.
Include Table C.8-28b “X-Ray Collimator Dimensions Macro Attributes” |

###### C.8.21.3.1.3 X-Ray 3D General Positioner Movement Macro

Table C.8.21.3.1.3-1 describes the X-Ray 3D General Positioner Movement Macro that specifies the Attributes that describe the movement of a positioner during the acquisition of more than one projection.

Table C.8.21.3.1.3-1. X-Ray 3D General Positioner Movement Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Primary Positioner Scan Arc | (0018,9508) | 1C | Total amount of rotation of the primary positioner in degrees. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Primary Positioner Scan Start Angle | (0018,9510) | 1C | Start position of the primary positioner in degrees. See Section C.8.7.5.1.2 or Section C.8.11.7, depending on modality and positioner type. Required if present and consistent in the contributing SOP Instances. Required if Modality (0008,0060) is MG.
Primary Positioner Increment | (0018,9514) | 1C | Constant increment of the primary positioner angle in degrees. Positive increment indicates an increasing value of the primary positioner angle. See Section C.8.7.5.1.2 or Section C.8.11.7 for the sign conventions depending on modality and positioner type. See Section C.8.21.3.1.3.1 for further explanation. Required if present and consistent in the contributing SOP Instances.
Primary Positioner Increment Sign | (0018,9518) | 3 | Direction of the primary positioner rotation. Defined Terms: +1 indicates a positive primary positioner angle increment -1 indicates a negative primary positioner angle increment See Section C.8.7.5.1.2 or Section C.8.11.7 for the sign conventions depending on modality and positioner type. See Section C.8.21.3.1.3.1 for further explanation.
Secondary Positioner Scan Arc | (0018,9509) | 1C | Total amount of rotation of the secondary positioner in degrees. Required if present and consistent in the contributing SOP Instances.
Secondary Positioner Scan Start Angle | (0018,9511) | 1C | Start position of the secondary positioner in degrees. See Section C.8.7.5.1.2 or Section C.8.11.7, depending on modality and positioner type. Required if present and consistent in the contributing SOP Instances.
Secondary Positioner Increment | (0018,9515) | 1C | Constant increment of the secondary positioner angle in degrees. Positive increment indicates an increasing value of the secondary positioner angle. See Section C.8.7.5.1.2 or Section C.8.11.7 for the sign conventions depending on modality and positioner type. See Section C.8.21.3.1.3.1 for further explanation. Required if present and consistent in the contributing SOP Instances.
Secondary Positioner Increment Sign | (0018,9519) | 3 | Direction of the secondary positioner rotation. Defined Terms: +1 indicates a positive secondary positioner angle increment -1 indicates a negative secondary positioner angle increment See Section C.8.7.5.1.2 or Section C.8.11.7 for the sign conventions depending on modality and positioner type. See Section C.8.21.3.1.3.1 for further explanation.

###### C.8.21.3.1.3.1 Positioner Angle Increments

If the increments of the positioner angles are constant during the acquisition of the X-Ray projections, the attributes Primary Positioner Increment (0018,9514) and the Secondary Positioner Increment (0018,9515) describe this angular change between projections.

If the change in positioner angle is not constant between the projections, omit the Positioner Angle Increment attributes and record the individual positioner angle values in the Positioner Angle attributes within each Item of the Per Projection Acquisition Sequence (0018,9538). In such case, the attributes Primary Positioner Increment Sign (0018,9518) and Secondary Positioner Increment Sign (0018,9519) are used to describe the direction of the positioner rotation.

##### C.8.21.3.2 X-Ray 3D Angiographic Acquisition Module

This section describes the X-Ray 3D Angiographic Acquisition Module.

Table C.8.21.3.2-1. X-Ray 3D Angiographic Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray 3D Acquisition Sequence | (0018,9507) | 1 | Each item represents an acquisition context related to one or more reconstructions. The values of Acquisition Index (0020,9518) may be used as index to Items in this sequence. One or more Items shall be included in this sequence.
>Field of View Shape | (0018,1147) | 1C | Shape of the Field of View in the referenced images. Enumerated Values: RECTANGLE ROUND HEXAGONAL Required if present and consistent in the contributing SOP Instances.
>X-Ray Receptor Type | (0018,9420) | 1C | Identifies the type of X-Ray receptor used. Enumerated Values: IMG_INTENSIFIER DIGITAL_DETECTOR Required if present and consistent in the contributing SOP Instances.
>Include Table C.8.21.3.1.1-1 “X-Ray 3D General Shared Acquisition Macro Attributes” |
>Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
>Physical Detector Size | (0018,9429) | 1C | Dimensions of the physical detector measured in mm as a row size followed by a column size. Required if present and consistent in the contributing SOP Instances.
>Position of Isocenter Projection | (0018,9430) | 1C | Position of the Isocenter measured in physical detector elements as a row offset followed by a column offset from the TLHC of a rectangle circumscribing the physical detector area. Required if Isocenter Reference System Sequence (0018,9462) is present and if the values are present and consistent in the contributing SOP Instances.
>Distance Source to Detector | (0018,1110) | 1C | Distance from source to receptor plane perpendicular to the receptor plane in mm or distance in mm from source to detector center on the chest wall line. See Section C.8.11.7.1.1. Required if present and consistent in the contributing SOP Instances. ### Note This value is traditionally referred to as Source Image Receptor Distance (SID).
>Distance Source to Isocenter | (0018,9402) | 1C | Distance from source to isocenter in mm. Required if present and consistent in the contributing SOP Instances.
>Focal Spot(s) | (0018,1190) | 1C | Nominal focal spot size in mm used to acquire this image. Required if present and consistent in the contributing SOP Instances.
>Filter Type | (0018,1160) | 1C | Type of filter(s) inserted into the X-Ray beam (e.g., wedges). See Attribute Description in Section C.8.7.10 for Defined Terms. ### Note Multiple type of filters can be expressed by a combination, e.g., BUTTERFLY+WEDGE. Required if present and consistent in the contributing SOP Instances.
>Filter Material | (0018,7050) | 1C | The X-Ray absorbing material used in the filter. May be multi-valued. See Attribute Description in Section C.8.7.10 for Defined Terms. Required if present and consistent in the contributing SOP Instances.
>Filter Thickness Minimum | (0018,7052) | 1C | See Attribute Description in Section C.8.7.10. Required if present and consistent in the contributing SOP Instances.
>Filter Thickness Maximum | (0018,7054) | 1C | See Attribute Description in Section C.8.7.10. Required if present and consistent in the contributing SOP Instances.
>Filter Beam Path Length Minimum | (0018,7056) | 1C | See Attribute Description in Section C.8.7.10. Required if present and consistent in the contributing SOP Instances.
>Filter Beam Path Length Maximum | (0018,7058) | 1C | See Attribute Description in Section C.8.7.10. Required if present and consistent in the contributing SOP Instances.
>Table X Position to Isocenter | (0018,9466) | 3 | X position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Y Position to Isocenter | (0018,9467) | 3 | Y position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Z Position to Isocenter | (0018,9468) | 3 | Z position of the Table Reference Point with respect to the Isocenter (mm). See Section C.8.19.6.13.1.3 for further explanation.
>Table Horizontal Rotation Angle | (0018,9469) | 3 | Rotation of the table in the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.
>Table Head Tilt Angle | (0018,9470) | 3 | Angle of the head-feet axis of the table in degrees relative to the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.
>Table Cradle Tilt Angle | (0018,9471) | 3 | Angle of the left-right axis of the table in degrees relative to the horizontal plane. See Section C.8.19.6.13.1.3 for further explanation.
>Include Table C.8.21.3.1.3-1 “X-Ray 3D General Positioner Movement Macro Attributes” |
>Per Projection Acquisition Sequence | (0018,9538) | 1C | Sequence containing detailed acquisition context of each individual projection used in this acquisition context. One or more Items shall be included in this sequence. Required if present and consistent in the contributing SOP Instances.
>>Include Table C.8.21.3.1.2-1 “X-Ray 3D General Per Projection Acquisition Macro Attributes” |
>>Positioner Isocenter Primary Angle | (0018,9463) | 1C | Position of the X-Ray center beam for this projection in the isocenter reference system in the X direction (deg). See Section C.8.19.6.13.1.2 for further explanation. Required if present and consistent in the contributing SOP Instances.
>>Positioner Isocenter Secondary Angle | (0018,9464) | 1C | Position of the X-Ray center beam for this projection in the isocenter reference system in the Z direction (deg). See Section C.8.19.6.13.1.2 for further explanation. Required if present and consistent in the contributing SOP Instances.
>>Positioner Isocenter Detector Rotation Angle | (0018,9465) | 1C | Rotation of the X-Ray detector plane for this projection (deg). See Section C.8.19.6.13.1.2 for further explanation. Required if present and consistent in the contributing SOP Instances.
>>Positioner Primary Angle | (0018,1510) | 3 | Position of the X-Ray Image Intensifier about the patient from the RAO to LAO direction where movement from RAO to vertical is positive. See Section C.8.7.5.1.2 for further explanation.
>>Positioner Secondary Angle | (0018,1511) | 3 | Position of the X-Ray Image Intensifier about the patient from the CAU to CRA direction where movement from CAU to vertical is positive. See Section C.8.7.5.1.2 for further explanation.

##### C.8.21.3.3 X-Ray 3D Craniofacial Acquisition Module

This section describes the X-Ray 3D Craniofacial Acquisition Module.

Table C.8.21.3.3-1. X-Ray 3D Craniofacial Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray 3D Acquisition Sequence | (0018,9507) | 1 | Each item represents a acquisition context related to a set of frames of SOP Instance defined by this IOD, The values of Acquisition Index (0020,9518) may be used as index to Items in this sequence. One or more Items shall be included in this sequence.
>Field of View Shape | (0018,1147) | 1C | Shape of the Field of View in the referenced images. Enumerated Values: RECTANGLE ROUND HEXAGONAL Required if present and consistent in the contributing SOP Instances.
>X-Ray Receptor Type | (0018,9420) | 1C | Identifies the type of X-Ray receptor used. Enumerated Values: DIGITAL_DETECTOR Required if present and consistent in the contributing SOP Instances.
>Include Table C.8.21.3.1.1-1 “X-Ray 3D General Shared Acquisition Macro Attributes” |
>Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
>Per Projection Acquisition Sequence | (0018,9538) | 1C | Sequence containing detailed acquisition context of each individual projection used in this acquisition context. One or more Items shall be included in this sequence. Required if present and consistent in the contributing SOP Instances.
>>Include Table C.8.21.3.1.2-1 “X-Ray 3D General Per Projection Acquisition Macro Attributes” |

##### C.8.21.3.4 Breast Tomosynthesis Acquisition Module

This section describes the Breast Tomosynthesis Acquisition Module.

Table C.8.21.3.4-1. Breast Tomosynthesis Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray 3D Acquisition Sequence | (0018,9507) | 1 | Each Item represents an acquisition context related to one or more reconstructions. The values of Acquisition Index (0020,9518) may be used as index in this sequence. One or more Items shall be included in this sequence.
>Field of View Shape | (0018,1147) | 1 | Shape of the Field of View in the source projection images. Enumerated Values: RECTANGLE
>X-Ray Receptor Type | (0018,9420) | 1 | Identifies the type of X-Ray receptor used. Enumerated Values: DIGITAL_DETECTOR
>Include Table C.8.21.3.1.1-1 “X-Ray 3D General Shared Acquisition Macro Attributes” |
>Include Table C.8.21.3.1.3-1 “X-Ray 3D General Positioner Movement Macro Attributes” |
>Distance Source to Detector | (0018,1110) | 1 | Distance in mm from source to detector center on the chest wall line. ### Note This value is traditionally referred to as Source Image Distance (SID). See Section C.8.11.7.1.1.
>Distance Source to Patient | (0018,1111) | 1 | Distance in mm from source to the breast support side that is closest to the Imaging Subject, as measured along the X-Ray beam vector. ### Note This value is traditionally referred to as Source Object Distance (SOD). See notes for this attribute in Section C.8.11.5 DX Positioning Module. See Section C.8.11.7.1.1 for description of X-Ray beam vector.
>Estimated Radiographic Magnification Factor | (0018,1114) | 1 | Ratio of Source Image Receptor Distance (SID) over Source Object Distance (SOD).
>Anode Target Material | (0018,1191) | 1 | The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
>Body Part Thickness | (0018,11A0) | 1 | The average thickness in mm of the body part examined when compressed, if compression has been applied during exposure.
>Exposure Control Mode | (0018,7060) | 1 | Type of exposure control. Defined Terms: MANUAL AUTOMATIC
>Exposure Control Mode Description | (0018,7062) | 1 | Text description of the mechanism of exposure control. May describe the number and type of exposure sensors or position of the sensitive area of the imaging detector.
>Half Value Layer | (0040,0314) | 1 | The thickness of Aluminum in mm required to reduce the X-Ray Output (0040,0312) by a factor of two. ### Note This value may be a calibrated value rather than measured during the exposure.
>Organ Dose | (0040,0316) | 3 | Organ dose value measured in dGy representing the collective total for all acquired frames described in this sequence item. ### Note This may be an estimated value.
>Entrance Dose in mGy | (0040,8302) | 3 | Entrance dose value measured in mGy at the surface of the patient representing the collective total for all acquired frames described in this sequence item. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
>Focal Spot(s) | (0018,1190) | 1 | Nominal focal spot size in mm used to acquire the projection images.
>Detector Binning | (0018,701A) | 1C | Number of active detectors used to generate a single pixel. Specified as number of row detectors per pixel then column. Required if detector binning was applied to the projection images.
>Detector Temperature | (0018,7001) | 1 | Detector temperature during exposure in degrees Celsius.
>Filter Type | (0018,1160) | 1 | Type of filter(s) inserted into the X-Ray beam (e.g., wedges). See Attribute Description in Section C.8.7.10 for Defined Terms.
>Filter Material | (0018,7050) | 1 | The X-Ray absorbing material used in the filter. May be multi-valued. See Attribute Description in Section C.8.7.10 for Defined Terms.
>Filter Thickness Minimum | (0018,7052) | 3 | See Attribute Description in Section C.8.7.10.
>Filter Thickness Maximum | (0018,7054) | 3 | See Attribute Description in Section C.8.7.10.
>Filter Beam Path Length Minimum | (0018,7056) | 3 | See Attribute Description in Section C.8.7.10.
>Filter Beam Path Length Maximum | (0018,7058) | 3 | See Attribute Description in Section C.8.7.10.
>Compression Force | (0018,11A2) | 1 | The compression force applied to the body part during exposure, measured in Newtons.
>Paddle Description | (0018,11A4) | 1 | Description of the compression paddle, if compression was applied to the body part during exposure.
>Per Projection Acquisition Sequence | (0018,9538) | 1 | Sequence containing detailed acquisition context of each individual projection used in this acquisition context. One or more Items shall be included in this sequence.
>>Include Table C.8.21.3.1.2-1 “X-Ray 3D General Per Projection Acquisition Macro Attributes” |
>>Positioner Primary Angle | (0018,1510) | 1 | Signed position in degrees of the X-Ray beam vector in the coronal anatomical plane as if the patient were standing facing the equipment where vertical is zero.
>>Positioner Primary Angle Direction | (0018,9559) | 3 | The interpretation of the sign of the Positioner Primary Angle (0018,1510). Enumerated Values: CW Clockwise. Positioner Primary Angle movement is positive when movement is from vertical to the patient's right (with patient standing, facing equipment). CC Counter clockwise. Positioner Primary Angle is positive when movement is from vertical to the patient's left (with patient standing, facing the equipment). See Section C.8.31.2.1.
>>Positioner Secondary Angle | (0018,1511) | 1C | Position in degrees of the X-Ray beam vector in the sagittal anatomical plane as if the patient were standing where movement of the X-Ray source from anterior to posterior is positive, and vertical is zero. Required if secondary positioner was used during acquisition.
>>Exposure Time in ms | (0018,9328) | 1 | Duration of X-Ray exposure in milliseconds. See Section C.8.7.2.1.1.
>>Exposure in mAs | (0018,9332) | 1 | The exposure expressed in milliampereseconds, for example calculated from Exposure Time and X-Ray Tube Current.
>>Relative X-Ray Exposure | (0018,1405) | 1 | Indication of the applied dose, in manufacturer specific units. ### Note This value is intended to provide a single location where manufacturer specific information can be found for annotation on a display or film, that has meaning to a knowledgeable observer. This may be a calculated or measured value. Examples are the detector entrance dose (KB), the CR sensitivity value (S), or the logarithmic median (lgM). This value is manufacturer-specific. DICOM specifies standard Attributes in Table 10-23 'Exposure Index Macro', which are recommended.
>>Organ Dose | (0040,0316) | 3 | Average organ dose value measured in dGy. ### Note This may be an estimated value.
>>Entrance Dose in mGy | (0040,8302) | 3 | Average entrance dose value measured in mGy at the surface of the patient during the acquisition of this projection image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
>>Include Table 10-23 “Exposure Index Macro Attributes” |
>>Irradiation Event UID | (0008,3010) | 3 | Unique identification of the irradiation event(s) associated with the acquisition of this image.

#### C.8.21.4 X-Ray 3D Reconstruction Module

This section describes the X-Ray 3D Reconstruction Module. Table C.8.21.4-1 contains IOD Attributes that describe the reconstructions used to create this SOP Instance. A single SOP Instance may contain the result of one or more reconstructions (e.g., a set of volumes). Each item in the X-Ray 3D Reconstruction Sequence specifies the characteristics of such a result.

Table C.8.21.4-1. X-Ray 3D Reconstruction Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray 3D Reconstruction Sequence | (0018,9530) | 1 | A sequence of Items each describing the characteristics of one 3D reconstruction included in this SOP instance. One or more Items shall be included in this sequence.
>Reconstruction Description | (0018,9531) | 3 | Free text description of the purpose of the reconstruction, e.g., mask volume.
>Application Name | (0018,9524) | 1 | Name of the application that created the reconstruction.
>Application Version | (0018,9525) | 1 | Version of the application that created the reconstruction.
>Application Manufacturer | (0018,9526) | 1 | Name of the manufacturer of the application that created the reconstruction.
>Algorithm Type | (0018,9527) | 1 | Type of algorithm used to create the reconstruction. Defined Terms: FILTER_BACK_PROJ ITERATIVE
>Algorithm Description | (0018,9528) | 3 | Description of the algorithm used to create the reconstruction.
>Acquisition Index | (0020,9518) | 1 | The Item number(s) of the X-Ray 3D Acquisition Sequence (0018,9507) that describes the acquisition context(s) contributing to this reconstruction.

#### C.8.21.5 X-Ray 3D Image Functional Group Macros

The following sections contain Functional Group Macros specific to the X-Ray 3D IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".".

##### C.8.21.5.1 X-Ray 3D Frame Type Macro

Table C.8.21.5.1-1 specifies the attributes of the X-Ray 3D Frame Type Functional Group Macro.

Table C.8.21.5.1-1. X-Ray 3D Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray 3D Frame Type Sequence | (0018,9504) | 1 | A sequence that describes general characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008), except that the value MIXED is not allowed. See Section C.8.21.1.1.1. For Breast Tomosynthesis Image See Section C.8.21.6.1.1.
>Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
>Reconstruction Index | (0020,9536) | 1C | The Item number of the X-Ray 3D Reconstruction Sequence (0018,9530) that describes the characteristics of the 3D Reconstruction to which this frame is part of. Required if the X-Ray 3D Reconstruction Sequence (0018,9530) is present.

#### C.8.21.6 Breast View Module

Table C.8.21.6-1 contains IOD Attributes that describe the view of a digital breast tomosynthesis image.

Table C.8.21.6-1. Breast View Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.21.6.1.1 for specialization.
View Code Sequence | (0054,0220) | 1 | Sequence that describes the view of the patient anatomy in this image. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” . | Defined CID 4014 “View for Mammography”.
>View Modifier Code Sequence | (0054,0222) | 2 | Sequence that provides modifiers for the view of the patient anatomy. Zero or more Items shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Defined CID 4015 “View Modifier for Mammography”.
Breast Implant Present | (0028,1300) | 1C | Whether or not the imaged breast contains a breast implant regardless of the visibility of a breast implant in the Pixel Data. Enumerated Values: YES NO Required if Modality (0008,0060) is MG. May be present otherwise. ### Note The value is expected to be YES for all images acquired on a breast that contains a breast implant, even when a breast implant is displaced during image acquisition.
Partial View | (0028,1350) | 3 | Indicates whether this image is a partial view, that is a subset of a single view of the breast. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not be a partial view. ### Note This may occur when a breast is larger than the active area of the detector. If this Attribute is present, its value shall be NO if there is a View Modifier Code Sequence (0054,0222) Item of value (R-102D6, SRT, "Magnification") or (R-102D7, SRT, "Spot Compression").
Partial View Code Sequence | (0028,1352) | 1C | Sequence that describes the portion or section of the breast captured in a partial view image. One or two Items shall be included in this sequence. See Section C.8.11.7.1.3. Required if Partial View (0028,1350) is present with a value of YES.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4005 “Partial View Section for Mammography”.

##### C.8.21.6.1 Breast View Module Attribute Description

###### C.8.21.6.1.1 Image Type and Frame Type

In addition to the requirements specified in Section C.8.21.1.1.1 Image Type and Frame Type, the following Defined Terms are specified for Value 3 of Image Type (0008,0008) and Frame Type (0008,9007):

Table C.8.21.6-1a. Defined Terms of Image Type (0008,0008) Value 3 for Contrast Enhanced, Tomosynthesis and Biopsy

Defined Term | Definition | ACR MQCM Equivalent
--- | --- | ---
Contrast
PRE_CONTRAST | Collected before contrast was administered. | n/a
POST_CONTRAST | Collected during or after contrast was administered. | n/a
Tomosynthesis
TOMO_PROJ | Identifies the image as a digital breast tomosynthesis projection image. | n/a
TOMOSYNTHESIS | Tomographic reconstruction from limited angle projection data. | n/a
Biopsy
TOMO_SCOUT | A localizer image set that may be used to determine positioning coordinates prior to needle positioning. | …SC
PREFIRE | An image set obtained with the biopsy needle in position prior to needle deployment. | …PRF
POSTFIRE | An image set obtained with the biopsy needle in position following needle deployment through the targeted lesion. | …POF
POSTBIOPSY | An image set obtained following tissue acquisition with the X-Ray source in the scout position. | …POB
POSTMARKER | An image set obtained following micromarker placement with the X-Ray source in the scout position. | …POM

### Note

There is no need for _MINUS or _PLUS because a single digital breast tomosynthesis acquisition produces a projection and/or reconstruction image set that replaces the _MINUS and _PLUS image pair used in conventional 2D breast biopsy imaging (see Section C.8.11.7.1.4).

If more than one characteristic (biopsy, tomosynthesis, contrast enhanced) applies to an image, Value 3 shall contain the biopsy image type. If biopsy is not involved, Value 3 shall contain the tomosynthesis image type.

### Note

For example, attributes of the Enhanced Contrast/Bolus Module may be used to identify contrast enhanced characteristics of a biopsy and/or tomosynthesis image that is also contrast enhanced.

Value 4 shall be NONE except for applicable contrast enhanced images, mathematically generated 2D images and other tomosynthesis reconstructions. The following Defined Terms are specified for Value 4 of Image Type (0008,0008) and Frame Type (0008,9007). For additional Defined Terms see Section C.8.16.1.4.

Table C.8.21.6-1b. Defined Terms of Image Type (0008,0008) Value 4 for Contrast Enhanced and Tomosynthesis

Defined Term | Definition
--- | ---
Tomosynthesis
GENERATED_2D | Mathematically generated 2D view.
MAXIMUM | Created through Pixel by pixel maximum operation.
MEAN | Created through Pixel by pixel mean operation.
Contrast
ADDITION | Created through Pixel by pixel addition operation.
SUBTRACTION | Created through Pixel by pixel subtraction operation.

If more than one characteristic (contrast enhanced, tomosynthesis) applies to an image, Value 4 shall contain the contrast enhanced image type. If contrast enhanced is not involved, Value 4 shall contain the tomosynthesis image type.

Value 5 shall be present for images acquired using contrast enhanced digital X-Ray imaging of the breast, but may be empty if none of the Defined Terms applies. For non-contrast images Value 5 remains optional and implementation specific.

Table C.8.21.6-1c. Defined Terms of Image Type (0008,0008) Value 5 for Contrast Enhanced Images

Enumerated Value | Definition
--- | ---
LOW_ENERGY | Low energy image.
HIGH_ENERGY | High energy image.

### Note

A recipient may use the different values for biopsy, tomosynthesis and contrast views to determine how to display them, for example in hanging protocols:

| Image Type Value 3 | Image Type Value 4 | Image Type Value 5
--- | --- | --- | ---
Tomosynthesis thin reconstructed slices | TOMOSYNTHESIS | NONE | -
Tomosynthesis thick reconstructed slices | TOMOSYNTHESIS | MAXIMUM | -
Tomosynthesis generated 2D | TOMOSYNTHESIS | GENERATED_2D | -
Tomosynthesis projections | TOMO_PROJ | NONE | -
Tomosynthesis thin reconstructed slices biopsy post-fire | POSTFIRE | NONE | -
Tomosynthesis thick reconstructed slices post-biopsy | POSTBIOPSY | MEAN | -
Tomosynthesis generated 2D biopsy pre-fire | PREFIRE | GENERATED_2D | -
Tomosynthesis projections biopsy scout | TOMO_SCOUT | NONE | -
Tomosynthesis thick reconstructed slices pre-contrast | TOMOSYNTHESIS | MAXIMUM | empty
Tomosynthesis thin reconstructed slices post-contrast subtraction | TOMOSYNTHESIS | SUBTRACTION | empty
Tomosynthesis thick reconstructed slices post-contrast subtraction | TOMOSYNTHESIS | SUBTRACTION | empty
Tomosynthesis generated 2D post-contrast addition | TOMOSYNTHESIS | ADDITION | empty
Tomosynthesis generated 2D post-contrast low energy | TOMOSYNTHESIS | GENERATED_2D | LOW_ENERGY
Tomosynthesis projections post-contrast high energy | TOMO_PROJ | NONE | HIGH_ENERGY
Tomosynthesis thick reconstructed slices biopsy scout pre-contrast | TOMO_SCOUT | MAXIMUM | empty
Tomosynthesis thin reconstructed slices biopsy pre-fire post-contrast subtraction | PREFIRE | SUBTRACTION | empty
Tomosynthesis thick reconstructed slices biopsy post-fire post-contrast subtraction | POSTFIRE | SUBTRACTION | empty
Tomosynthesis generated 2D post-biopsy post-contrast addition | POSTBIOPSY | ADDITION | empty
Tomosynthesis generated 2D biopsy scout post-contrast low energy | TOMO_SCOUT | GENERATED_2D | LOW_ENERGY
Tomosynthesis projections post-biopsy post-contrast high energy | POSTBIOPSY | NONE | HIGH_ENERGY

### C.8.22 Enhanced PET Modules

This section describes the specific modules for the Enhanced PET Image IOD.

#### C.8.22.1 Enhanced PET Series Module

The Enhanced PET IODs use the General Series module described in Section C.7.3.1, specialized by the Enhanced PET Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of PET device.

Table C.8.22-1 specifies the Attributes that identify and describe general information about the Enhanced PET Series.

Table C.8.22-1. Enhanced PET Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: PT See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Related Series Sequence | (0008,1250) | 1C | Identifying the series that was used for attenuation purposes. See Section C.7.3.1 Required if another series was used to perform attenuation correction and the SOP Class UID is not "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted). May be present otherwise. One or more Items shall be included in this sequence.
>Study Instance UID | (0020,000D) | 1 | Instance UID of Study to which the related Series belongs
>Series Instance UID | (0020,000E) | 1 | Instance UID of Related Series
>Purpose of Reference Code Sequence | (0040,A170) | 2 | Describes the purpose for which the reference is made. Zero or more Items shall be included in this sequence. When absent, implies that the reason for the reference is unknown.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7210 “Related Series Purposes of Reference”.

#### C.8.22.2 Enhanced PET Acquisition Module

Table C.8.22-2 specifies the Attributes that describe PET Acquisitions.

Table C.8.22-2. Enhanced PET Acquisition Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Acquisition Start Condition | (0018,0073) | 1C | Description of how the data collection was started. See Section C.8.22.2.1.1 for Defined Terms. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Start Density Threshold | (0018,9715) | 1C | The count density that triggered the start of the acquisition, in counts/sec. Required if Acquisition Start Condition (0018,0073) equals DENS.
Start Relative Density Difference Threshold | (0018,9716) | 1C | The relative count density that triggered the start of the acquisition, in counts/sec. Required if Acquisition Start Condition (0018,0073) equals RDD.
Start Cardiac Trigger Count Threshold | (0018,9717) | 1C | The number of cardiac triggers that occurred before starting the acquisition. Required if Acquisition Start Condition (0018,0073) equals CARD_TRIG.
Start Respiratory Trigger Count Threshold | (0018,9718) | 1C | The number of respiratory triggers that occurred before starting the acquisition. Required if Acquisition Start Condition (0018,0073) equals RESP_TRIG.
Acquisition Termination Condition | (0018,0071) | 1C | Description of how the data collection for the series was stopped. See Section C.8.22.2.1.2 for Defined Terms. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Termination Counts Threshold | (0018,9719) | 1C | The count value that triggered the termination of the acquisition. Required if Acquisition Termination Condition (0018,0071) equals CNTS.
Termination Density Threshold | (0018,9720) | 1C | The count density that triggered the termination of the acquisition, in counts/sec. Required if Acquisition Termination Condition (0018,0071) equals DENS.
Termination Relative Density Threshold | (0018,9721) | 1C | The count relative density that triggered the termination of the acquisition, in counts/sec. Required if Acquisition Termination Condition (0018,0071) equals RDD.
Termination Time Threshold | (0018,9722) | 1C | The time duration after which the acquisition was terminated, in sec. Required if Acquisition Termination Condition (0018,0071) equals TIME
Termination Cardiac Trigger Count Threshold | (0018,9723) | 1C | The number of cardiac triggers that triggered the termination of the acquisition. Required if Acquisition Termination Condition (0018,0071) equals CARD_TRIG
Termination Respiratory Trigger Count Threshold | (0018,9724) | 1C | The number of respiratory triggers that triggered the termination of the acquisition. Required if Acquisition Termination Condition (0018,0071) equals RESP_TRIG
Type of Detector Motion | (0054,0202) | 1C | Describes the type of detector motion during acquisition. Defined Terms: STATIONARY No motion STEP AND SHOOT Interrupted motion, acquire only while detectors are stationary CONTINUOUS Gantry motion and acquisition are simultaneous and continuous WOBBLE wobble motion CLAMSHELL clamshell motion Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Detector Geometry | (0018,9725) | 1C | Physical arrangement of the detectors in the acquisition system. The radiation entrance surface of a detector may be curved or flat. A curved surface is referred to as cylindrical. Detectors may simultaneously subtend all possible transverse angles from the center of the field of view. Detectors that do not are referred to as partial. Defined Terms: CYLINDRICAL_RING CYL_RING_PARTIAL MULTIPLE_PLANAR MUL_PLAN_PARTIAL Required if Image Type (0008,0008) Value 1 is ORIGINAL and Type of Detector Motion (0054,0202) equals STATIONARY. May be present otherwise, if Image Type (0008,0008) Value 1 is DERIVED and Type of Detector Motion (0054,0202) equals STATIONARY.
Transverse Detector Separation | (0018,9726) | 1C | Distance between opposing detectors, in mm. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Axial Detector Dimension | (0018,9727) | 1C | Axial detector size in mm. Size of the detector along the table axis. Required if Image Type (0008,0008) Value 1 is ORIGINAL May be present otherwise.
Collimator Type | (0018,1181) | 1C | Collimator Type. Defined Terms: NONE no collimator RING transverse septa Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Coincidence Window Width | (0054,1210) | 1C | The width of the coincidence-timing window, in nanoseconds. The maximum time difference between two single events in two opposing detectors that will be accepted as a coincidence event. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Energy Window Range Sequence | (0054,0013) | 1C | Sequence of Items that describes the energy windows used for this Image. One or more items shall be included in this sequence. See Section C.8.22.2.1.3 for explanation. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
>Energy Window Lower Limit | (0054,0014) | 1 | The lower limit of the energy window, in KeV.
>Energy Window Upper Limit | (0054,0015) | 1 | The upper limit of the energy window, in KeV.
Table Motion | (0018,1134) | 1 | Enumerated Values: STATIC Table is stationary during data acquisition. DYNAMIC Table is moving during data acquisition.
Time of Flight Information Used | (0018,9755) | 1 | Specifies whether or not Time-of-Flight information was used in creation of the image. Enumerated Values: TRUE FALSE
Include Table 10-24 “Mandatory View and Slice Progression Direction Attributes” |
Isocenter Position | (300A,012C) | 3 | Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the patient-based coordinate system associated with the Frame of Reference. It allows transformation from the equipment-based coordinate system to the patient-based coordinate system.
Scan Progression Direction | (0054,0501) | 3 | The anatomical order in which the slices were acquired. Enumerated Values: FEET_TO_HEAD Slices closest to the patient's feet were acquired first. HEAD_TO_FEET Slices closest to the patient's head were acquired first.

##### C.8.22.2.1 Enhanced PET Acquisition Module Attribute Descriptions

###### C.8.22.2.1.1 Acquisition Start Condition

Acquisition Start Condition (0018,0073) is the method of starting acquisition data collection.

Defined Terms:

DENS

  preset count density (counts/sec) was reached

RDD

  preset relative count density difference (change in counts/sec) was reached

MANU

  acquisition was started manually

AUTO

  start automatically, when ready

CARD_TRIG

  preset number of cardiac triggers was reached

RESP_TRIG

  preset number of respiratory triggers was reached

###### C.8.22.2.1.2 Acquisition Termination Condition

Acquisition Termination Condition (0018,0071) is the method of acquisition termination that has actually applied to the data collection.

Defined Terms:

CNTS

  preset counts was reached

DENS

  preset count density (counts/sec) was reached

RDD

  preset relative count density difference (change in counts/sec) was reached

MANU

  acquisition was terminated manually

OVFL

  data overflow occurred

TIME

  preset time limit was reached

CARD_TRIG

  preset number of cardiac triggers was reached

RESP_TRIG

  preset number of respiratory triggers was reached

###### C.8.22.2.1.3 Energy Window Range Sequence

Multiple energy windows are allowed in order to allow coincidence events based on additional Energy Windows (e.g., Compton events scattered in the detector). All energy windows are assumed to contribute to all frames in this image.

#### C.8.22.3 Enhanced PET Image Module

Table C.8.22-3 specifies the attributes of the Enhanced PET Image Module.

Table C.8.22-3. Enhanced PET Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image characteristics. See Section C.8.22.3.1.1.
Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |
Acquisition Number | (0020,0012) | 3 | A number identifying the single continuous gathering of data over a period of time that resulted in this image, which may include multiple bed positions. ### Note This number is not required to be unique across SOP Instances in a series. See also the description of the Referenced Raw Data Sequence (0008,9121).
Acquisition DateTime | (0008,002A) | 1C | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800). See Section C.7.6.16.2.2.1 for an overview of all acquisition related timing attributes. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted), may be present otherwise.
Acquisition Duration | (0018,9073) | 1C | The time in seconds needed to complete the acquisition of data. See Section C.7.6.16.2.2.1 for further explanation. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL and SOP Class UID is not "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted), may be present otherwise.
Referenced Raw Data Sequence | (0008,9121) | 3 | A sequence that identifies the set of Raw Data SOP Class/Instance pairs of the Raw data that were used to derive this Image. One or more Items are permitted in this Sequence. ### Note The items of in this sequence may identify raw data that has not been stored or encoded as a DICOM object. This allows recognition that images and spectra in different instances have been reconstructed from the same raw data. For such items the SOP Class UID would be "1.2.840.10008.5.1.4.1.1.66" (Raw Data SOP Class) and the SOP Instance UID would be any appropriate UID.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Waveform Sequence | (0008,113A) | 3 | References to waveforms acquired in conjunction with this image. These Waveforms may or may not be temporally synchronized with this image. One or more Items are permitted in this sequence.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” | Defined CID 7004 “Waveform Purposes of Reference”.
Referenced Image Evidence Sequence | (0008,9092) | 1C | Full set of Composite SOP Instances referring to image SOP Instances inside the frames of this Enhanced PET Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Source Image Evidence Sequence | (0008,9154) | 1C | Full set of Composite SOP Instances used as source image SOP Instances inside the frames of this Enhanced PET Image SOP Instance. See Section C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Source Image Sequence (0008,2112) is present.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. This value shall be 1.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME2 See Section C.7.6.3.1.2 for definition of this term.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. This value shall be 16.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. This value shall be 16.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Content Qualification | (0018,9004) | 1 | Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See Section C.8.13.2.1.1 for further explanation.
Image Comments | (0020,4000) | 3 | User-defined comments about the image
Burned in Annotation | (0028,0301) | 1C | Indicates that the image does not contain burned in annotations. Enumerated Values: NO This means that images that contain this Module shall not contain burned in annotations. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted), may be present otherwise.
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression | (0028,2110) | 1C | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5. Required if SOP Class UID is not "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted). May be present otherwise.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of the Lossy Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1 | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6 for further explanation.

##### C.8.22.3.1 Enhanced PET Image Description Attribute Description

###### C.8.22.3.1.1 Image Type and Frame Type

The Image Type Attribute (0008,0008) and Frame Type (0008,9007) identifies important image characteristics in a multiple valued data element. In addition to the requirements specified in Section C.8.16.1 Image Type and Frame Type, the following additional requirements and Defined Terms are specified:

###### C.8.22.3.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

###### C.8.22.3.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

###### C.8.22.3.1.1.3 Image Flavor

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.3. No additional requirements or Defined Terms.

###### C.8.22.3.1.1.4 Derived Pixel Contrast

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.4. No additional requirements or Defined Terms.

###### C.8.22.3.1.2 Attenuation Correction Source

The attribute Attenuation Correction Source (0018,9738) contains the source of the attenuation map information used for attenuation correction.

Defined Terms:

CT

MR

POSITRON SOURCE

SINGLE PHOTON

CALCULATED

  Emission data is used to calculate the correction map.

###### C.8.22.3.1.3 Attenuation Correction Temporal Relationship

The attribute Attenuation Correction Temporal Relationship (0018,9770) specifies the temporal relationship between the attenuation correction source image and the PET image data.

Defined Terms:

CONCURRENT

  The attenuation correction source image is acquired at approximately the same time and with the patient in the same body position as the PET image; for example, as acquired on a hybrid scanner

SEPARATE

  The attenuation correction source image is acquired at a different time, on a different system, or the patient has been moved significantly enough to cause soft tissue movement; for example, an attenuation correction source image acquired on a separate CT scanner, so that the patient must move from one bed to another

SIMULTANEOUS

  The attenuation correction source image is acquired at the same time and with the patient in the same body position as the PET image

#### C.8.22.4 Enhanced PET Isotope Module

Table C.8.22-9 contains IOD Attributes that describe a PET Isotope.

Table C.8.22-9. Enhanced PET Isotope Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Radiopharmaceutical Information Sequence | (0054,0016) | 1 | Sequence of Items that describe isotope information. One or more items shall be included in this sequence.
>Radiopharmaceutical Agent Number | (0018,9729) | 1 | Identifying number, unique within this SOP Instance, of the agent administered. Used to reference this particular agent from the Radiopharmaceutical Functional Group Macro. The number shall be 1 for the first item and increase by 1 for each subsequent Item.
>Radionuclide Code Sequence | (0054,0300) | 1 | Sequence that identifies the radionuclide. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4020 “PET Radionuclide”.
>Administration Route Code Sequence | (0054,0302) | 1 | Sequence that identifies the administration route of the radiopharmaceutical. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 11 “Route of Administration”.
>Radiopharmaceutical Volume | (0018,1071) | 3 | Volume of administered radiopharmaceutical in cubic cm.
>Radiopharmaceutical Start DateTime | (0018,1078) | 1 | Time of start of administration. The actual time of radiopharmaceutical administration to the patient for imaging purposes.
>Radiopharmaceutical Stop DateTime | (0018,1079) | 3 | Time of end of administration. The actual ending time of radiopharmaceutical administration to the patient for imaging purposes.
>Radionuclide Total Dose | (0018,1074) | 2 | The radiopharmaceutical dose administered to the patient measured in MegaBecquerels (MBq) at the Radiopharmaceutical Start DateTime (0018,1078).
>Radiopharmaceutical Administration Event UID | (0008,3012) | 3 | Unique identification of the administration of the radiopharmaceutical to the patient. ### Note The UID is the same Radiopharmaceutical Administration Event UID that is in the Radiopharmaceutical Radiation Dose Report.
>Radionuclide Half Life | (0018,1075) | 1 | The radionuclide half life, in seconds, that was used in the correction of this image.
>Radionuclide Positron Fraction | (0018,1076) | 1 | The radionuclide positron fraction (fraction of decays that are by positron emission) that was used in the correction of this image.
>Radiopharmaceutical Specific Activity | (0018,1077) | 3 | The activity per unit mass of the radiopharmaceutical, in Bq/micromole, at the Radiopharmaceutical Start DateTime (0018,1078).
>Radiopharmaceutical Code Sequence | (0054,0304) | 1 | Sequence that identifies the radiopharmaceutical. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 4021 “PET Radiopharmaceutical”.

#### C.8.22.5 Enhanced PET Image Functional Group Macros

The following sections contain Functional Group Macros specific to the Enhanced PET Image IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".

##### C.8.22.5.1 PET Frame Type Macro

Table C.8.22-10 specifies the attributes of the PET Frame Type Functional Group Macro.

Table C.8.22-10. PET Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Frame Type Sequence | (0018,9751) | 1 | A sequence that describes general characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008) attribute, except that the value MIXED is not allowed unless the SOP Class UID is "1.2.840.10008.5.1.4.1.1.128.1" (Legacy Converted). See Section C.8.16.1 and Section C.8.22.3.1.
>Include Table C.8-131 “Common CT/MR Image Description Macro Attributes” |

##### C.8.22.5.2 PET Frame Acquisition Macro

Table C.8.22-11 specifies the attributes of the PET Frame Acquisition Functional Group Macro.

Table C.8.22-11. PET Frame Acquisition Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Frame Acquisition Sequence | (0018,9732) | 1 | Contains the attributes defining the PET acquisition mode. Only a single Item shall be included in this sequence.
>Table Height | (0018,1130) | 1 | The distance in mm from the top of the patient table to the data collection center. The distance is positive when the table is below the data collection center.
>Gantry/Detector Tilt | (0018,1120) | 1 | Nominal angle of tilt in degrees of the scanning gantry. Not intended for mathematical computations. Zero degrees means the gantry is not tilted, negative degrees are when the top of the gantry is tilted away from where the table enters the gantry.
>Gantry/Detector Slew | (0018,1121) | 1 | Nominal angle of slew in degrees of the gantry. Not intended for mathematical computations. Zero degrees means the gantry is no slewed. Positive slew is moving the gantry on the patient's left toward the patient's superior, when the patient is supine.
>Data Collection Diameter | (0018,0090) | 1 | The diameter in mm of the region over which data were collected. See Section C.8.22.5.4.1.

##### C.8.22.5.3 PET Detector Motion Details Macro

Table C.8.22-12 specifies the attributes of the PET Detector Motion Details Functional Group Macro.

Table C.8.22-12. PET Detector Motion Details Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Detector Motion Details Sequence | (0018,9733) | 1 | Contains the attributes defining the details of the motion of the Detector. Only a single Item shall be included in this sequence.
>Rotation Direction | (0018,1140) | 1 | Direction of rotation of the detector about the gantry, as viewed while facing the gantry where the table enters the gantry. Enumerated Values: CW clockwise CC counter clockwise
>Revolution Time | (0018,9305) | 1 | The time in seconds of a complete revolution of the detector around the gantry orbit.

##### C.8.22.5.4 PET Position Macro

Table C.8.22-14 specifies the attributes of the PET Position Functional Group Macro.

Table C.8.22-14. PET Position Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Position Sequence | (0018,9735) | 1 | Contains the attributes defining the PET geometry. Only a single Item shall be included in this sequence.
>Table Position | (0018,9327) | 1C | Relative longitudinal position of acquisition location of this frame in mm from an implementation specific reference point. Shall be relative to the same reference point for all frames in this SOP Instance, but may be different from the reference point in other SOP Instances. Positions as the table moves into the gantry viewed from the front are more negative. ### Note For contiguous slices reconstructed from multiple detectors one would expect different values for adjacent slices. Lateral positioning or tilting or swiveling are not described. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Data Collection Center (Patient) | (0018,9313) | 1C | The x, y, and z coordinates (in the patient coordinate system) in mm of the center of the region in which data were collected. See Section C.8.22.5.4.1. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.
>Reconstruction Target Center (Patient) | (0018,9318) | 1C | The x, y, and z coordinates (in the patient coordinate system) of the reconstruction center target point as used for reconstruction in mm. See Section C.8.22.5.4.1. ### Note If the reconstructed image is not magnified or panned the value corresponds with the Data Collection Center (0018,9313) attribute. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.

###### C.8.22.5.4.1 Relationships Between PET Geometric Attributes (Informative)

In Figure C.8.22-1 the relationship of the Geometric Attributes within the PET Geometry and PET Reconstruction functional groups is shown. Figure C.8.22-1, viewed from the front of the gantry (where the table enters the gantry), is informative only and is not meant to represent a standardization of an equipment-based frame of reference.

Figure C.8.22-1. Geometry of PET Acquisition System

##### C.8.22.5.5 PET Frame Correction Factors Macro

Table C.8.22-15 specifies the attributes of the PET Frame Correction Factors Functional Group Macro.

Table C.8.22-15. PET Frame Correction Factors Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Frame Correction Factors Sequence | (0018,9736) | 1 | Contains the attributes that describe the correction factors applied to this frame. Only a single Item shall be included in this sequence.
>Primary (Prompts) Counts Accumulated | (0054,1310) | 1C | The sum of events that occur in the primary event channel. The counts include Trues +Scatter+ Randoms if Corrected Image (0028,0051) includes RAN; otherwise the counts are Trues +Scatter. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Slice Sensitivity Factor | (0054,1320) | 1C | The slice-to-slice sensitivity correction factor that was used to correct this frame. The value shall be one if no slice sensitivity correction was applied. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Decay Factor | (0054,1321) | 1C | The decay factor that was used to scale this frame. Required if Decay Corrected (0018,9758) equals YES.
>Scatter Fraction Factor | (0054,1323) | 1C | An estimate of the fraction of acquired counts that were due to scatter and that were corrected in this frame. The value shall be zero if no scatter correction was applied. Required if Frame Type (0008,9007Value 1 is ORIGINAL. May be present otherwise.
>Dead Time Factor | (0054,1324) | 1C | The average dead time correction factor that was applied to this frame. The value shall be one if no dead time correction was applied. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.

##### C.8.22.5.6 PET Reconstruction Macro

Table C.8.22-17 specifies the attributes of the PET Reconstruction Functional Group Macro, which describe the method used to reconstruct this image.

Table C.8.22-17. PET Reconstruction Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Reconstruction Sequence | (0018,9749) | 1 | Contains the attributes describing the reconstruction process for this frame. Only a single Item shall be included in this sequence.
>Reconstruction Type | (0018,9756) | 1C | Description of the type of algorithm used when reconstructing the image from the data acquired during the acquisition process. Defined Terms: 2D 3D 3D_REBINNED Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.
>Reconstruction Algorithm | (0018,9315) | 1C | Description of the algorithm used when reconstructing the image from the data acquired during the acquisition process. Defined Terms: FILTER_BACK_PROJ REPROJECTION RAMLA MLEM Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Iterative Reconstruction Method | (0018,9769) | 1 | Iterative Reconstruction Method used. Enumerated Values: YES NO
>Number of Iterations | (0018,9739) | 1C | Number of iterations. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL and Iterative Reconstruction Method (0018,9769) equals YES. May be present otherwise.
>Number of Subsets | (0018,9740) | 1C | Number of subsets. Required if Frame Type (0008,9007)) Value 1 equals ORIGINAL and Iterative Reconstruction Method (0018,9769) equals YES. May be present otherwise.
>Reconstruction Diameter | (0018,1100) | 1C | The diameter in mm of the region from which data were used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region. See Section C.8.22.5.4.1. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL and Reconstruction Field of View (0018,9317) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 equals DERIVED and Reconstruction Field of View (0018,9317) is not present.
>Reconstruction Field of View | (0018,9317) | 1C | The field of view width (x-dimension) followed by height (y-dimension) as used for reconstruction in mm. Required if Image Type (0008,9007) Value 1 equals ORIGINAL and Reconstruction Diameter (0018,1100) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 equals DERIVED and Reconstruction Diameter (0018,1100) is not present.

##### C.8.22.5.7 PET Table Dynamics Macro

Table C.8.22-18 specifies the attributes of the PET Table Dynamics Functional Group Macro, which describes the table motion during acquisition of the data.

Table C.8.22-18. PET Table Dynamics Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
PET Table Dynamics Sequence | (0018,9734) | 1 | Contains the attributes describing the movement of the PET Table. Only a single Item shall be included in this sequence.
>Table Speed | (0018,9309) | 1 | The distance in mm that the Table moves in one second during the gathering of data that resulted in this frame.

#### C.8.22.6 Enhanced PET Corrections Module

Table C.8.22-19 specifies the attributes of the Enhanced PET Corrections Module.

Table C.8.22-19. Enhanced PET Corrections Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Counts Source | (0054,1002) | 1 | The primary source of counts. Enumerated Values: EMISSION TRANSMISSION
Decay Corrected | (0018,9758) | 1 | Decay (DECY) correction has been applied to image. Enumerated Values: YES NO
Attenuation Corrected | (0018,9759) | 1 | Attenuation (ATTN) correction has been applied to image. Enumerated Values: YES NO
Scatter Corrected | (0018,9760) | 1 | Scatter (SCAT) correction has been applied to image. Enumerated Values: YES NO
Dead Time Corrected | (0018,9761) | 1 | Dead time (DTIM) correction has been applied to image. Enumerated Values: YES NO
Gantry Motion Corrected | (0018,9762) | 1 | Gantry motion (MOTN) correction has been applied to image. Enumerated Values: YES NO
Patient Motion Corrected | (0018,9763) | 1 | Patient motion (PMOT) correction has been applied to image. Enumerated Values: YES NO
Count Loss Normalization Corrected | (0018,9764) | 1 | Count loss (CLN) normalization correction has been applied to image. Enumerated Values: YES NO
Randoms Corrected | (0018,9765) | 1 | Randoms (RAN) correction has been applied to image. Enumerated Values: YES NO
Non-uniform Radial Sampling Corrected | (0018,9766) | 1 | Non-uniform radial sampling (RADL) correction has been applied to image. Enumerated Values: YES NO
Sensitivity Calibrated | (0018,9767) | 1 | Image is sensitivity calibrated using a dose calibrator (DCAL). Enumerated Values: YES NO
Detector Normalization Correction | (0018,9768) | 1 | Detector normalization (NORM) correction has been applied to image. Enumerated Values: YES NO
Randoms Correction Method | (0054,1100) | 1C | Type of randoms correction processing. Defined Terms: DLYD delayed event subtraction SING singles estimation PDDL Processed Delays, which is a correction based on a processed (filtered) version of the data acquired from the delayed coincidence channel. Required if Randoms Corrected (0018,9765) equals YES.
Attenuation Correction Source | (0018,9738) | 1C | Contains the source of the attenuation map information used for attenuation correction. See Section C.8.22.3.1.2 Required if Attenuation Corrected (0018,9759) equals YES.
Attenuation Correction Temporal Relationship | (0018,9770) | 1C | Contains the temporal relationship between the attenuation correction source image and the PET image data. See Section C.8.22.3.1.3 Required if Attenuation Corrected (0018,9759) equals YES.
Scatter Correction Method | (0054,1105) | 1C | A textual description of the scatter correction processing. e.g., convolution-subtraction, dual energy window, model-based, use of attenuation data. Required if Scatter Corrected (0018,9760) equals YES.
Decay Correction DateTime | (0018,9701) | 1C | The date and time to which all frames in this Image were decay corrected. Required if Decay Corrected (0018,9758) equals YES.

### C.8.23 Surface Segmentation

This section describes the specific modules for the Surface Segmentation IOD.

#### C.8.23.1 Surface Segmentation Module

Table C.8.23-1 defines the general Attributes of the Surface Segmentation Module.

Table C.8.23-1. Surface Segmentation Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Include Table 10-12 “Content Identification Macro Attributes” |
Content Date | (0008,0023) | 1 | The date the content creation started.
Content Time | (0008,0033) | 1 | The time the content creation started.
Segment Sequence | (0062,0002) | 1 | Describes the segments that are contained within the data. One or more Items shall be included in this sequence.
>Include Table C.8.20-4 “Segment Description Macro Attributes” |
>Surface Count | (0066,002A) | 1 | The number of surfaces that comprise this segment. Shall be greater than zero.
>Referenced Surface Sequence | (0066,002B) | 1 | Sequence referencing the surfaces composed to construct this segment. One or more Items shall be included in this sequence. The number of Items shall equal the value of Surface Count (0066,002A).
>>Referenced Surface Number | (0066,002C) | 1 | Identifies the Surface Number (0066,0003) within the Surface Sequence (0066,0002) to which this reference applies.
>>Segment Surface Generation Algorithm Identification Sequence | (0066,002D) | 1 | A description of how this segment surface was derived. Only a single Item shall be included in this sequence.
>>>Include Table 10-19 “Algorithm Identification Macro Attributes” | For Algorithm Family Code Sequence (0066,002F) Baseline CID 7162 “Surface Processing Algorithm Families”.
>>Segment Surface Source Instance Sequence | (0066,002E) | 2 | A Sequence that identifies the set of Instances by their SOP Class/Instance pair that were used to derive this segment surface. Zero or more items shall be included in this Sequence.
>>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |

### C.8.24 Enhanced US Volume Modules and Functional Group Macros

#### C.8.24.1 Enhanced US Series Module

Table C.8.24.1-1 specifies attributes for the Enhanced US Series Module, including specialization of attributes in the General Series Module for use in the Enhanced US Series Module.

Table C.8.24.1-1. Enhanced US Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: US IVUS See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Performed Protocol Code Sequence | (0040,0260) | 1C | Sequence describing a Protocol being followed for this Procedure Step. Only a single Item shall be included in this sequence. Required if a Protocol is controlling the creation of this Series. May be present otherwise.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 12001 “Ultrasound Protocol Types”.
>Protocol Context Sequence | (0040,0440) | 3 | Sequence that specifies the context for the Performed Protocol Code Sequence Item. One or more items are permitted in this sequence.
>>Include Table 10-2 “Content Item Macro Attributes Description” | No Baseline TID is defined.
>>Content Item Modifier Sequence | (0040,0441) | 3 | Sequence that specifies modifiers for a Protocol Context Content Item. One or more items are permitted in this sequence. See Section C.4.10.1.
>>>Include Table 10-2 “Content Item Macro Attributes Description” | No Baseline TID is defined.
Performed Protocol Type | (0040,0261) | 1C | Type of protocol performed. Enumerated Values: STAGED NON_STAGED Required if Performed Protocol Code Sequence (0040,0260) is present.

#### C.8.24.2 Ultrasound Frame of Reference Module

Table C.8.24.2-1 specifies the attributes of the Ultrasound Frame Of Reference Module. See Section C.8.24.2.1.

Table C.8.24.2-1. Ultrasound Frame of Reference Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Volume Frame of Reference UID | (0020,9312) | 1 | Uniquely identifies this Volume Frame of Reference.
Ultrasound Acquisition Geometry | (0020,9307) | 1 | Characteristic of the ultrasound acquisition geometry. Defined Terms: APEX there exists an apex of the scan lines from which the volume data was acquired.
Apex Position | (0020,9308) | 1C | Position of the apex (or phase center) of the acquisition geometry, encoded as xA, yA, and zA in mm units in the Volume Frame of Reference. The apex (xA, yA, zA) may be located in the volume or exterior to it. Required if value of Ultrasound Acquisition Geometry (0020,9307) is APEX.
Volume to Transducer Relationship | (0020,930B) | 1C | Relationship between the transducer and the acquired volume. Enumerated Values: FIXED The transducer position and orientation relative to the volume is constant and specified by Volume to Transducer Mapping Matrix (0020,9309). POSITION_VAR The transducer position relative to the volume varies during acquisition and the position specified by Volume to Transducer Mapping Matrix (0020,9309) is a nominal value. The transducer orientation relative to the volume is constant and specified by Volume to Transducer Mapping Matrix (0020,9309). ORIENTATION_VAR The transducer orientation relative to the volume varies during acquisition and the orientation specified by Volume to Transducer Mapping Matrix (0020,9309) is a nominal value. The transducer position relative to the volume is constant and specified by Volume to Transducer Mapping Matrix (0020,9309). VARIABLE The transducer position and orientation relative to the volume varies during acquisition and the position and orientation specified by Volume to Transducer Mapping Matrix (0020,9309) are nominal. Required if the transducer position and/or orientation relative to the volume is not constant. May be present otherwise.
Volume to Transducer Mapping Matrix | (0020,9309) | 1 | A 4x4 rigid transformation matrix that maps the Volume Frame of Reference homogeneous coordinate system (XV, YV, ZV) to the Transducer Frame of Reference homogeneous coordinate system (XX,YX, ZX). Matrix elements shall be listed in row-major order. See Section C.8.24.2.1 for details.
Patient Frame of Reference Source | (0020,930C) | 1C | Indicates how the supplied Image Position (Patient) (0020,0032) and Image Orientation (Patient) (0020,0037) values are obtained. Enumerated Values: TABLE A positioning device, such as a gantry, was used to generate these values. ESTIMATED Estimated patient position / orientation (e.g., estimated by the user), or if reliable information is not available. REGISTRATION Acquisition has been spatially registered to a prior image set. Required if either Image Position (Patient) (0020,0032) or Image Orientation (Patient) (0020,0037) is present.
Table Frame of Reference UID | (0020,9313) | 1C | Uniquely identifies this Table Frame of Reference. Required if Patient Frame of Reference Source (0020,930C) is TABLE.
Volume to Table Mapping Matrix | (0020,930A) | 1C | A 4x4 rigid transformation matrix that maps the Volume Frame of Reference homogeneous coordinate system (XV,YV, ZV) to the Table Frame of Reference homogeneous coordinate system (XT,YT, ZT). Matrix elements shall be listed in row-major order. See Section C.8.24.2.2 for details. Required if Patient Frame of Reference Source (0020,930C) is TABLE.

##### C.8.24.2.1 Ultrasound Frame of Reference Module Overview

The Ultrasound Frame of Reference Module is used to relate the image planes to a frame of reference appropriate for the ultrasound modality, most notably a volume-based frame of reference. There are many different transducer scan acquisition geometries used in 3D ultrasound imaging. Regardless of the acquisition geometry, after acquisition of the initial scan images comprising the volume, the ultrasound (US) scanner will assemble (reformat) the data into a proper Cartesian volume with the assumption that the data are related through a Right-Hand Coordinate System (RHCS). x-positions are defined in mm with positive values increasing towards the right. y-positions are defined in mm with positive values in the direction of increasing image depth. z-positions are defined in mm with positive values in the direction as defined in a right-hand coordinate system.

A Cartesian volume will consist of a series of 1 to n parallel planes. The image planes comprising the Cartesian volume are typically oriented during creation of the volume so that the best image quality is in the XY plane. Table C.8.24.2-1 specifies the attributes of the Ultrasound Frame of Reference Module. There are three levels of detail for the Ultrasound Frame of Reference: Volume, Transducer and Table.

###### C.8.24.2.1.1 Volume Frame of Reference

The Volume Frame of Reference is a Right-hand Coordinate System consisting of a Volume Origin at the location (0,0,0) and mutually orthogonal XV, YV, and ZV axes in a Right-Hand Coordinate System. The particular IOD using the Volume Frame of Reference may constrain the alignment of frames with respect to the axes of the Volume Frame of Reference. For example, Figure C.8.24.2-1 illustrates the use of the Volume Frame of Reference with frames whose rows are parallel to the XV axis and columns are parallel to the YV axis and whose origins lie on the ZV axis.

Figure C.8.24.2-1. Volume Frame of Reference

###### C.8.24.2.1.2 Transducer Frame of Reference

The Transducer Frame of Reference is a Right-hand Coordinate System consisting XX, YX, and ZX axes originating at a reference "Transducer Origin" defined as the geometric center of the transducer face.

The orientation of the Transducer Frame of Reference relative to the Volume Origin is such that the YX axis is normal to the transducer face and the "direction reference" (i.e., transducer tactile marker or zero reference) is aligned with the positive XX axis. A transformation is specified between the Volume Frame of Reference and the Transducer Frame of Reference to define the position of the transducer relative to the volume. This transformation is specified by the Volume to Transducer Mapping Matrix (0020,9309).

The Transducer Frame of Reference recognizes two types of scan geometry: 1) a scan geometry with a real apex such as would be the case for a pyramid, toroid or rotational volume acquisition, or 2) a scan geometry for which there is no specific apex. The point (xA, yA, zA) is the apex (or phase center) of the acquisition volume geometry in the Volume Frame of Reference. The apex (xA, yA, zA) may be located in the volume or exterior to it.

Figure C.8.24.2-2. Transducer Frame of Reference

In some acquisition modalities, the transducer position and/or orientation changes during acquisition and a single transducer mapping matrix is insufficient to describe the relationship between transducer and volume. In this case, Volume to Transducer Relationship (0020,930B) is required and specifies the nature of the relationship Transducer Frame of Reference and the Volume Frame of Reference.

###### C.8.24.2.1.3 Table Frame of Reference

There also may exist a fixed equipment reference called the Table Frame of Reference, a Right-hand Coordinate System consisting of XT, YT, and ZT axes originating at a reference "Table Origin". See Figure C.8.24.2-3.

### Note

In this context the Table Frame of Reference refers to a fixed coordinate system in space that may be provided by a variety of source devices such as coordinates from a magnetic position sensor, LED sensor array, a physical scanner gantry, or similar device.

A transformation may be specified between the Volume Frame of Reference and the Table Frame of Reference to define the position and orientation of the volume relative to this external frame of reference. This transformation is specified by the Volume to Table Mapping Matrix (0020,930A).

Figure C.8.24.2-3. Table Frame of Reference

##### C.8.24.2.2 Ultrasound Frame of Reference Module Attributes

###### C.8.24.2.2.1 Volume to Transducer Mapping Matrix

The Volume to Transducer Mapping Matrix (0020,9309) is used to describe the relationship between the Transducer Frame of Reference coordinate system and the Volume Frame of Reference coordinate system.

The Volume to Transducer Mapping Matrix ([MTV] = [P]*[Q]) describes how to transform a point (XV, YV, ZV) in the Volume coordinate system into (XX,YX, ZX) in the Transducer coordinate system according to the equation below.

Where:

XVYVZV

  The voxel location (in mm) in the Volume Frame of Reference

XXYXZX

  The voxel location (in mm) in the Transducer Frame of Reference

Pij,Pij,Pij

  A 3x3 matrix of direction cosine values as measured to the Transducer origin from the volume origin.

Qx,Qy,Qz

  The translation values (in mm) describe the location in mm of the Transducer Frame of Reference (XX,YX, ZX) origin from the Volume Reference Origin (XV,YV, ZV) measured in millimeters along the Volume axes i.e., to the transducer origin from the volume origin.

###### C.8.24.2.2.2 Volume to Table Mapping Matrix

The Volume to Table Mapping Matrix (0020,930A) is used to describe the relationship between the Volume Frame of Reference coordinate system and a modality specific equipment coordinate system. This mapping can be used only with systems that have a well-defined equipment coordinate system.

The Volume to Table Mapping Matrix([MVG] = [R]*[S]) describes how to transform a point (XVYVZV) in the Volume coordinate system into (XT, YT, ZT) in the Table coordinate system according to the equation below.

Equation C.8.24-1.

Where:

XVYVZV

  The voxel location (in mm) in the Volume Frame of Reference

XTYTZT

  The voxel location (in mm) in the Table Frame of Reference

Rij,Rij,Rij

  A 3x3 matrix of direction cosine values as measured to the gantry origin from the volume origin.

Sx,Sy,Sz

  The translation values (in mm) describe the location in mm of the Table Frame of Reference (XT, YT, ZT) origin from the Volume Reference Origin (XV,YV, ZV) measured in millimeters along the table axes i.e., to the table origin from the volume origin.

### Note

The Mapping Matrices are rigid transformations that involve only translations and rotations. Mathematically, the matrix is orthonormal and describes six degrees of freedom: three translations, and three rotations.

#### C.8.24.3 Enhanced US Image Module

Table C.8.24.3-1 specifies the Attributes that describe the Enhanced US Image Module. As described in Section A.1.2.6, the Attributes in this Module apply to the first frame of a multi-frame image; any or all of this information may be overridden by Attributes in Per-frame Functional Groups.

Table C.8.24.3-1. Enhanced US Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.24.3.2 for specialization.
Samples Per Pixel | (0028,0002) | 1 | Number of samples per pixel in this image. Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME2
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Enumerated Values: 8 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Enumerated Values: 7 15
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. The constrained Enumerated Value implies the VR of all Palette Color Lookup Table Descriptors be US (and not SS). Enumerated Values: 0000H unsigned integer See Section C.8.24.3.1 for specialization.
Dimension Organization Type | (0020,9311) | 1 | Dimension organization of the instance. Enumerated Values: 3D 3D_TEMPORAL See Section C.8.24.3.3 for details.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started.
Acquisition Duration | (0018,9073) | 1 | Duration of the image acquisition in seconds.
Pixel Spacing | (0028,0030) | 1 | Physical distance in the patient between the centers of adjacent pixels, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing, in mm. See Section 10.7.1.3 for further explanation of the value order.
Position Measuring Device Used | (0018,980C) | 1C | Describes the type of position measuring device used in the acquisition of the image, if any. This gives an indication of the degree of precision of Pixel Spacing (0028,0030) and the spacing between adjacent planes. Enumerated Values: RIGID The image was acquired with a position measuring device. FREEHAND The image was acquired without a position measuring device. Required if Volumetric Properties (0008,9206) is VOLUME and Volume Based Calculation Technique (0008,9207) is NONE. May be present otherwise.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Presentation LUT Shape | (2050,0020) | 1 | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values.
Rescale Intercept | (0028,1052) | 1 | The value b in relationship between stored values (SV) and the output units. Output units = m*SV + b. Enumerated Values: 0
Rescale Slope | (0028,1053) | 1 | m in the equation specified by Rescale Intercept (0028,1052). Enumerated Values: 1
Source Image Sequence | (0008,2112) | 1C | A Sequence that identifies the set of Image SOP Class/Instance pairs of the Images that were used to derive this Image. One or more Items shall be included in this Sequence. See Section C.7.6.1.1.4 for further explanation. Required if Image Type (0008,0008) Value 1 is DERIVED.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made. Only a single item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7202 “Source Image Purposes of Reference”.
Referenced Image Sequence | (0008,1140) | 3 | A sequence that references other images significantly related to this image. (e.g., an image containing spatially related frames) One or more Items are permitted in this sequence.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made. Only a single item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7201 “Referenced Image Purposes of Reference”.
Referenced Raw Data Sequence | (0008,9121) | 3 | A sequence that identifies the set of Raw Data SOP Class/Instance pairs of the raw data that were used to derive this Image. One or more Items are permitted in this Sequence.
>Include Table C.17-3 “Hierarchical SOP Instance Reference Macro Attributes” |
Referenced Instance Sequence | (0008,114A) | 1C | A sequence that provides reference to a set of non-image SOP Class/Instance pairs significantly related to this Image, including waveforms that may or may not be temporally synchronized with this image. One or more Items shall be included in this sequence. Required if waveforms are acquired in conjunction with image acquisition. May be present otherwise.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Code describing the purpose of the reference to the Instance(s). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7004 “Waveform Purposes of Reference” for referenced waveforms.
Number of Stages | (0008,2124) | 1C | Number of stages in this protocol. Required if Performed Protocol Type (0040,0261) is present with value STAGED.
Stage Number | (0008,2122) | 1C | A number that identifies the Stage. Stage Number starts at one. Required if Performed Protocol Type (0040,0261) is present with value STAGED.
Stage Code Sequence | (0040,000A) | 1C | Sequence describing the performed Ultrasound Protocol Stage. Only a single item shall be included in this sequence. Required if Performed Protocol Type (0040,0261) is present with value STAGED.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 12002 “Ultrasound Protocol Stage Types”.
Include Table 10-24 “Mandatory View and Slice Progression Direction Attributes” | See Section C.8.5.6.1.19 for Context Group ID's.
Event Timer Sequence | (0008,2133) | 3 | Sequence of time intervals of significance to this image. Each item describes one time interval either beginning or ending at Acquisition DateTime (0008,002A). One or more Items are permitted in this Sequence.
>Event Time Offset | (0008,2134) | 1 | Signed value of the time between Acquisition DateTime (0008,002A) and the event, in milliseconds. Positive values indicate the event occurs after Acquisition DateTime (0008,002A).
>Event Code Sequence | (0008,2135) | 1 | Type of event. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 12031 “Protocol Interval Events”.
>Event Timer Name(s) | (0008,2132) | 3 | Name that identifies the event timer. May be used in addition to Event Time Code Sequence to offer site-specific user-readable event time names. Only a single value shall be included.
Include Table 10-5 “General Anatomy Mandatory Macro Attributes” | No Context IDs are specified.
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 3 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the image. Only a single item is permitted in this sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See Section C.7.6.1.1.6 for further explanation.
Transducer Data | (0018,5010) | 3 | Manufacturer defined code or description
Transducer Scan Pattern Code Sequence | (0018,9809) | 1 | The scan pattern the transducer is capable of. Only a single item shall be included in this sequence. See Section C.8.24.3.4 for further explanation.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 12032 “Transducer Scan Pattern”.
Transducer Geometry Code Sequence | (0018,980D) | 1 | Geometric structure of the transducer. Only a single item shall be included in this sequence. See Section C.8.24.3.4 for further explanation.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 12033 “Ultrasound Transducer Geometry”.
Transducer Beam Steering Code Sequence | (0018,980E) | 1 | Technique used by the transducer for beam steering. One or more items shall be included in this sequence. If more than one item is present, the order is significant from plane-forming technique to volume-forming technique. See Section C.8.24.3.4 for further explanation.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 12034 “Ultrasound Transducer Beam Steering”.
Transducer Application Code Sequence | (0018,980F) | 1 | The primary clinical application of the transducer. Only a single Item shall be included in this sequence. See Section C.8.24.3.4 for further explanation.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 12035 “Ultrasound Transducer Application”.
Processing Function | (0018,5020) | 3 | Manufacturer defined description of processing of echo information. Data may include code or description of gain (initial, overall, TGC, dynamic range, etc.), pre-processing, post-processing, Doppler processing parameters, e.g., cutoff filters, etc., as used in generating a given image.
Mechanical Index | (0018,5022) | 1 | See Section C.8.5.6.1.8 for Description.
Bone Thermal Index | (0018,5024) | 1 | See Section C.8.5.6.1.8 for Description.
Cranial Thermal Index | (0018,5026) | 1 | See Section C.8.5.6.1.8 for Description.
Soft Tissue Thermal Index | (0018,5027) | 1 | See Section C.8.5.6.1.8 for Description.
Depth(s) of Focus | (0018,9801) | 1 | The depth or depths from the transducer face, of the manufacturer defined beam focus points used for the image, in mm.
Depth of Scan Field | (0018,5050) | 1 | The depth, in mm, from the transducer face to the deepest point included in the image- the field of view.

##### C.8.24.3.1 Pixel Representation

Pixel Representation (0028,0103) is specified to be Type 1 with the constraint that VR for all the pixel data will always be unsigned (US) and not signed (SS).

Enumerated Values:

0000H

  unsigned integer

### Note

The real-world values that are inherently signed (e.g., Flow Velocity, Tissue Velocity, Variance) are represented as unsigned, unitless pixel values and may be mapped to signed real-world quantities via the Real World Value Mapping Macro.

##### C.8.24.3.2 Image Type

Image Type (0008,0008) is specified to be Type 1 with the following constraints:

Enumerated Values for Value 1:

ORIGINAL

DERIVED

Enumerated Values for Value 2:

PRIMARY

Value 3 (Image Flavor) and Value 4 are not used

##### C.8.24.3.3 Dimension Organization Type

Dimension Organization Type (0020,9311) specifies the general structure of the image. The concept of "multi-frame dimensions" as specified by the Dimension Index Sequence (0020,9222) and per-frame Dimension Index Values (0020,9157) shall be used to specify the relationships of frames within that general structure.

If Dimension Organization Type (0020,9311) has values of 3D or 3D_TEMPORAL, then the Dimension Index Sequence (0020,9222) shall have exactly three items, with the dimension values described in Table C.8.24.3.3-1.

Table C.8.24.3.3-1. Dimension Definition for US Acquisition 3D Images

Item | Attribute | Tag | Value
--- | --- | --- | ---
Dimension Index Sequence | (0020,9222) |
1st | >Dimension Index Pointer | (0020,9165) | Tag of attribute specifying temporal position of frames
>Functional Group Pointer | (0020,9167) | Tag of sequence containing above attribute
… |  |
2nd | >Dimension Index Pointer | (0020,9165) | (0020,9301) Image Position (Volume)
>Functional Group Pointer | (0020,9167) | (0020,930E) Plane Position (Volume) Sequence
… |  |
3rd | >Dimension Index Pointer | (0020,9165) | (0018,9808) Data Type
>Functional Group Pointer | (0020,9167) | (0018,9807) Image Data Type Sequence
… |  |

The Dimension Index Values (0020,9157) corresponding to these dimension variables positively associate frames with different Data Type values at the same spatial and temporal position. Figure C.8.24.3.3-1 illustrates the use of Dimensions to associate frames with temporal, spatial, and Data Type dimensions.

These Dimension values shall be used even if there is only one possible value for a Dimension.

### Note

For example, if Dimension Organization Type (0020,9311) has the value 3D, the temporal position dimension is present and the dimension index of the temporal attribute is the same in every frame of the image. Similarly, if the Data Type attribute is in the Shared Functional Group and all frames in the object are of Data Type TISSUE_INTENSITY, the Data Type dimension is present and the dimension index of the Data Type dimension is the same in every frame of the image.

Each plane in the volume consists of one or more frames each with a distinct value of Data Type (0018,9808). Adjacent planes in the volume shall be equally spaced in the Z direction.

Each frame comprising a volume shall have the same value of the temporal dimension attribute. Any appropriate physiological event temporal attribute may be used to specify the temporal position. If there is no specific physiological event to which the temporal position of frames is referenced, then Temporal Position Time Offset (0020,930D) in the Temporal Position Sequence (0020,9310) may be used as the temporal dimension attribute. If all frames are at the same temporal position, any temporal attribute may be referenced.

### Note

For example, the attribute specifying temporal position of frames may be any appropriate temporal attribute, such as Nominal Cardiac Trigger Delay Time (0020,9153) or Nominal Percentage of Cardiac Phase (0020,9241) in the Cardiac Synchronization Sequence (0018,9118) if the temporal position of frames is referenced to the cardiac R-wave, or Nominal Respiratory Trigger Delay Time (0020,9255) or Nominal Percentage of Respiratory Phase (0020,9245) in the Respiratory Synchronization Sequence (0020,9253) if the temporal position of frames is referenced to the latest inspiration maximum.

Figure C.8.24.3.3-1. Dimension Organization Type Frame Relationships

##### C.8.24.3.4 Transducer Description

The following elements together describe the type of transducer used to acquire the image. These are characteristics of the transducer itself rather than its specific use in the acquisition of this image. In other words, these attribute values are determined from the construction and design of the transducer and a given transducer generally has the same values of these attributes in every image it is used to create.

- Transducer Scan Pattern Code Sequence (0018,9809)

The shape of the acoustic scan field the transducer is capable of.

- Transducer Geometry Code Sequence (0018,980D)

The physical scan aperture from which acoustic pulses are emitted and received.

- Transducer Beam Steering Code Sequence (0018,980E)

The method used to steer acoustic beam.

- Transducer Application Code Sequence (0018,980F)

The placement on the subject for which the transducer is designed.

Each probe model has a unique set of values of these attributes. For example, these sample probes have the following characteristics, which are encoded in the attributes above:

Table C.8.24.3.4-1. Sample Transducer Characteristics

Model | Scan Pattern | Geometry | Beam Steering | Application
--- | --- | --- | --- | ---
Pedoff CW | Line | NonImaging | Fixed direction | External
Phased array sector probe | Plane | Sector | Phased | External
Steerable TEE | Plane | Sector | Phased, Mechanical | Transesophogeal
Curved Linear Abdominal | Plane | Curved Linear | Phased | External
Endovaginal | Plane | Curved Linear | Phased | Endovaginal
Mechanical 3D | Volume | Sector | Phased, Mechanical | External
Phased 3D | Volume | Sector | Phased | External
Endovaginal 3D | Volume | Curved Linear | Phased, Mechanical | Endovaginal

#### C.8.24.4 IVUS Image Module

Table C.8.24.4-1 specifies the Attributes of an IVUS Module.

Table C.8.24.4-1. IVUS Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
IVUS Acquisition | (0018,3100) | 1 | Defined Terms: MOTOR_PULLBACK MANUAL_PULLBACK SELECTIVE GATED_PULLBACK See Section C.8.5.6.1.21
IVUS Pullback Rate | (0018,3101) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK. Specified in units of mm/sec. See Section C.8.5.6.1.22
IVUS Gated Rate | (0018,3102) | 1C | Required if IVUS Acquisition (0018,3100) value is GATED_PULLBACK. Specified in units of mm/beat. See Section C.8.5.6.1.23
IVUS Pullback Start Frame Number | (0018,3103) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See Section C.8.5.6.1.24
IVUS Pullback Stop Frame Number | (0018,3104) | 1C | Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See Section C.8.5.6.1.25

#### C.8.24.5 Excluded Intervals Module

The Excluded Intervals Module indicates those periods within Acquisition Duration (0018,9073) during which no volume acquisition takes place. It provides information not available at the frame level or image level, since individual frames of the volume may have been built-up over a time period within which some intervals were excluded from acquisition. Further, it provides information that is not specific to associated waveform objects since the fact that volume acquisition was excluded during these intervals is a characteristic of the volume, not the associated waveform(s), see Figure C.8.24.5-1. Table C.8.24.5-1 specifies the attributes of the Excluded Intervals Module.

### Note

For example, if the imaging device performing a gated volume acquisition excludes volume data acquired during an ectopic beat, the Excluded Intervals attributes would be used to mark this interval in an associated physio waveform display.

Table C.8.24.5-1. Excluded Intervals Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Excluded Intervals Sequence | (0018,9803) | 1C | List of excluded intervals. One or more items shall be included in this sequence. Required if one or more intervals was excluded.
>Exclusion Start DateTime | (0018,9804) | 1 | Time-point of the exclusion start in the same Synchronization Frame of Reference as Acquisition DateTime (0008,002A).
>Exclusion Duration | (0018,9805) | 1 | Duration of the exclusion in ms.

Figure C.8.24.5-1. Relationship of Timing Related Attributes

#### C.8.24.6 Enhanced US Volume Functional Group Macros

The following sections contain Functional Group Macros specific to the Enhanced US Volume IOD.

### Note

The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e., the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean " for all frames".

##### C.8.24.6.1 US Image Description Macro

Table C.8.24.6.1-1 specifies the attributes of the US Image Description Functional Group Macro.

Table C.8.24.6.1-1. US Image Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
US Image Description Sequence | (0018,9806) | 1 | A sequence that describes a general description of this image or frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008), except that the value MIXED is not allowed. See Section C.8.24.3.2.
>Volumetric Properties | (0008,9206) | 1 | Indication if geometric manipulations are possible with frames in the SOP Instance. See Section C.8.16.2.1.2 for a description and Enumerated Values.
>Volume Based Calculation Technique | (0008,9207) | 1 | Method used for volume calculations with frames in the SOP Instance. See Section C.8.16.2.1.3 for a description and Defined Terms.

If Volumetric Properties (0008,9206) is VOLUME and Volume Based Calculation Technique (0008,9207) is NONE, all frames in the frame set shall be spaced the same Z-distance from adjacent frames (i.e., spacing between slices is constant).

### C.8.25 Ophthalmic Refractive Measurements Modules

#### C.8.25.1 Lensometry Measurements Series Module

The Lensometry Measurements IODs use the General Series module described in Section C.7.3.1, specialized by the Lensometry Measurements Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of Ophthalmic device.

Table C.8.25.1-1 specifies the Attributes that identify and describe general information about the Lensometry Measurements Series.

Table C.8.25.1-1. Lensometry Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: LEN See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.2 Autorefraction Measurements Series Module

The Autorefraction Measurements IODs use the General Series module described in Section C.7.3.1, specialized by the Autorefraction Measurements Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of Ophthalmic device.

Table C.8.25.2-1 specifies the Attributes that identify and describe general information about the Autorefraction Measurements Series.

Table C.8.25.2-1. Autorefraction Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: AR See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.3 Keratometry Measurements Series Module

The Keratometry Measurements IODs use the General Series module described in Section C.7.3.1, specialized by the Keratometry Measurements Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of Ophthalmic device.

Table C.8.25.3-1 specifies the Attributes that identify and describe general information about the Keratometry Measurements Series.

Table C.8.25.3-1. Keratometry Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: KER See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.4 Subjective Refraction Measurements Series Module

The Subjective Refraction Measurements IODs use the General Series module described in Section C.7.3.1, specialized by the Subjective Refraction Measurements Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of Ophthalmic device.

Table C.8.25.4-1 specifies the Attributes that identify and describe general information about the Subjective Refraction Measurements Series.

Table C.8.25.4-1. Subjective Refraction Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: SRF See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.5 Visual Acuity Measurements Series Module

The Visual Acuity Measurements IODs use the General Series module described in Section C.7.3.1, specialized by the Visual Acuity Measurements Series Module, to describe the DICOM Series Entity described in Section A.1.2.3, and to define what constitutes a Series for the context of Ophthalmic device.

Table C.8.25.5-1 specifies the Attributes that identify and describe general information about the Visual Acuity Measurements Series.

Table C.8.25.5-1. Visual Acuity Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: VA See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.6 General Ophthalmic Refractive Macros

##### C.8.25.6.1 Cylinder Sequence Macro

Table C.8.25.6.1-1 describes the attributes for the Cylinder Sequence Macro

Table C.8.25.6.1-1. Cylinder Sequence Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Cylinder Sequence | (0046,0018) | 1C | A sequence that specifies lens measurements to correct for astigmatism or measurements of an eye that has astigmatism. Required if astigmatic correction or astigmatism is measured. Only a single item shall be included in this sequence. ### Note When astigmatism is present the power is NOT the same in all meridians, but has its minimum and maximum power in meridians separated by 90 degrees.
>Cylinder Power | (0046,0147) | 1 | The power that is present at the power meridian (90 degrees from the axis), in diopters.
>Cylinder Axis | (0022,0009) | 1 | The meridian, defined in degrees, that is 90 degrees from the power meridian.

##### C.8.25.6.2 Prism Sequence Macro

Table C.8.25.6.2-1 describes the attributes for the Prism Sequence Macro

Table C.8.25.6.2-1. Prism Sequence Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Prism Sequence | (0046,0028) | 1C | A sequence that specifies prism that is measured in a lens, or that is required to correct for a patient's ocular misalignment. Required if prism is measured in the lens or if this part of a refraction is done for a patient. Only a single item shall be included in this sequence. ### Note A prism is a wedge shaped lens that deviates light toward the base and shifts the apparent image toward its apex.
>Horizontal Prism Power | (0046,0030) | 1 | The power of a prism to bend light in the horizontal direction, in prism diopters.
>Horizontal Prism Base | (0046,0032) | 1 | Direction of the base of the measured prism -- either in (toward the nose), or out (away from the nose) Enumerated Values: IN OUT
>Vertical Prism Power | (0046,0034) | 1 | The power of a prism to bend light in the vertical direction, in prism diopters.
>Vertical Prism Base | (0046,0036) | 1 | Direction of the base of the measured prism -- either up, or down. Enumerated Values: UP DOWN

#### C.8.25.7 General Ophthalmic Refractive Measurements Module

Table C.8.25.7-1 defines the General Ophthalmic Refractive Measurements module attributes.

Table C.8.25.7-1. General Ophthalmic Refractive Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Instance Number | (0020,0013) | 1 | A number that identifies these measurements.
Content Date | (0008,0023) | 1 | The date the measurements data creation started.
Content Time | (0008,0033) | 1 | The time the measurements data creation started.
Image Comments | (0020,4000) | 3 | User-defined comments about this SOP Instance.
Referenced Refractive Measurements Sequence | (0046,0145) | 2C | A sequence that specifies Ophthalmic Refractive Measurements SOP Instances that are relevant to the interpretation of this SOP Instance. Zero or more items shall be included in this sequence. See Section C.8.25.7.1.1 for further explanation. Required if Visual Acuity Type Code Sequence (0046,0121) is present. May be present otherwise.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

##### C.8.25.7.1 General Ophthalmic Refractive Measurements Module Attributes

###### C.8.25.7.1.1 Referenced Refractive Measurements Sequence

Whenever visual acuity is measured it is necessary to know the conditions under which it was measured. If the vision was measured with the patient's habitual correction in place, this attribute is used to reference a lensometry measurements SOP instance for the current glasses. If the measurements are of the patient's best-corrected vision, this attribute may reference the SOP instance that describes the correction that resulted in that vision, which may for example be the subjective refraction, or the autorefraction.

This attribute enables a receiver of this SOP instance to identify the results of measurements from a lensometer, autorefractor, or automated phoropter (subjective refraction) that are relevant to interpretation.

#### C.8.25.8 Lensometry Measurements Module

Table C.8.25.8-1 defines the Attributes used to capture the refractive measurements by a lensometer for spectacles. This is typically for a pair of lenses, but sometimes for just one. Sometimes a single lens is measured with an unknown laterality.

Table C.8.25.8-1. Lensometry Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Lens Description | (0046,0012) | 2 | A free text description of the lens and lens general comments. ### Note A common example is to identify the specific spectacles measured
Right Lens Sequence | (0046,0014) | 1C | A sequence that specifies measurements of a patient's right lens. Required if the right lens is measured. Only a single Item shall be included in this sequence.
>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes” |
Left Lens Sequence | (0046,0015) | 1C | A sequence that specifies measurements of a patient's left lens. Required if the left lens is measured. Only a single Item shall be included in this sequence.
>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes” |
Unspecified Laterality Lens Sequence | (0046,0016) | 1C | A sequence that specifies measurements of one lens of unknown laterality. Only a single Item shall be included in this sequence. Shall not be included if Attribute Right Lens Sequence (0046,0014) or Left Lens Sequence (0046,0015) is present. Required if a single lens of unknown laterality is measured.
>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes” |

Table C.8.25.8-2 describes the attributes for the Lensometry Measurements Macro.

Table C.8.25.8-2. Lensometry Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Sphere Power | (0046,0146) | 1 | Refractive power of the lens that is the same in all meridians, measured at distance (optical infinity), in diopters.
Include Table C.8.25.6.1-1 “Cylinder Sequence Macro Attributes” |
Add Near Sequence | (0046,0100) | 1C | A sequence that specifies refractive measurements of the lens to correct for inability to focus at near while wearing the distance prescription. Only a single item shall be included in this sequence. Required if Add Near is measured in the lens.
>Add Power | (0046,0104) | 1 | Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.
>Viewing Distance | (0046,0106) | 3 | The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this sequence.
Add Intermediate Sequence | (0046,0101) | 1C | A sequence that specifies refractive measurements of the lens to correct for inability to focus at intermediate distance while wearing the distance prescription. Only a single item shall be included in this sequence. Required if Add intermediate is measured in the lens.
>Add Power | (0046,0104) | 1 | Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.
>Viewing Distance | (0046,0106) | 3 | The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this sequence item.
Include Table C.8.25.6.2-1 “Prism Sequence Macro Attributes” |
Lens Segment Type | (0046,0038) | 3 | The type of segment of a lens containing the "add" power, as described above Enumerated Values: PROGRESSIVE NONPROGRESSIVE
Optical Transmittance | (0046,0040) | 3 | The fraction of light that passes through the measured lens optical media, in percent.
Channel Width | (0046,0042) | 3 | In a progressive lens, the width in mm of that portion of the lens where there is gradual or progressive increase in "add" power. ### Note See Attributes, Add Near Sequence (0046,0100) and Add Intermediate Sequence (0046,0101) for description of"add".

#### C.8.25.9 Autorefraction Measurements Module

Table C.8.25.9-1 defines the Attributes used to represent the refractive measurements by an autorefractor of a patient's eyes. Usually both eyes are measured, but sometimes just one.

Table C.8.25.9-1. Autorefraction Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Autorefraction Right Eye Sequence | (0046,0050) | 1C | A sequence that specifies refractive measurements of a patient's right eye. Only a single item shall be included in this sequence. Required if the right eye is measured.
>Sphere Power | (0046,0146) | 1 | Refractive power of the eye that is the same in all meridians, measured at distance (optical infinity), in diopters.
>Include Table C.8.25.6.1-1 “Cylinder Sequence Macro Attributes” |
>Pupil Size | (0046,0044) | 3 | The horizontal diameter measurement of the pupil, in mm.
>Corneal Size | (0046,0046) | 3 | The horizontal diameter measurement of the cornea, in mm.
Autorefraction Left Eye Sequence | (0046,0052) | 1C | A sequence that specifies refractive measurements of a patient's left eye. Only a single item shall be included in this sequence. Required if the left eye is measured.
>Sphere Power | (0046,0146) | 1 | Refractive power of the eye that is the same in all meridians, measured at distance (optical infinity), in diopters.
>Include Table C.8.25.6.1-1 “Cylinder Sequence Macro Attributes” |
>Pupil Size | (0046,0044) | 3 | The horizontal diameter measurement of the pupil, in mm.
>Corneal Size | (0046,0046) | 3 | The horizontal diameter measurement of the cornea, in mm.
Distance Pupillary Distance | (0046,0060) | 3 | Distance in mm between the pupils when the patient's object of regard is in the distance, as measured by an autorefractor.
Near Pupillary Distance | (0046,0062) | 3 | Distance in mm between the pupils when the patient's object of regard is at near, as measured by an autorefractor.

#### C.8.25.10 Keratometry Measurements Module

Table C.8.25.10-1 defines the Attributes used to represent the keratometric measurements by a keratometer of a patient's eyes. Usually both eyes are measured, but sometimes just one.

Table C.8.25.10-1. Keratometry Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Keratometry Right Eye Sequence | (0046,0070) | 1C | A sequence that specifies keratometric measurements of a patient's right eye, defining principal meridians wherein the steepest meridian is separated by 90 degrees from the flattest. Only a single item shall be included in this sequence. Required if the right eye is measured. ### Note Consideration for steep, flat, and spherical meridians is made. For instances where spherical keratometric measurements are obtained, values specified in the steep and flat Attributes are equivalent.
>Include Table C.8.25.10-2 “Keratometric Measurements Macro Attributes” |
Keratometry Left Eye Sequence | (0046,0071) | 1C | A sequence that specifies keratometric measurements of a patient's left eye, defining principal meridians wherein the steepest meridian is separated by 90 degrees from the flattest. Only a single item shall be included in this sequence. Required if the left eye is measured. ### Note See Note for attribute Keratometry Right Eye Sequence (0046,0070)
>Include Table C.8.25.10-2 “Keratometric Measurements Macro Attributes” |

Table C.8.25.10-2 describes the attributes for the Keratometric Measurements Macro.

Table C.8.25.10-2. Keratometric Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Steep Keratometric Axis Sequence | (0046,0074) | 1 | A sequence that specifies the steepest meridian as defined by the greatest power of curvature and shortest radius of curvature. Only a single item shall be included in this sequence.
>Radius of Curvature | (0046,0075) | 1 | The radius of curvature of the principal meridians of the cornea, measured in mm.
>Keratometric Power | (0046,0076) | 1 | The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis | (0046,0077) | 1 | The meridian where the keratometric radius of curvature or power is measured, in degrees.
Flat Keratometric Axis Sequence | (0046,0080) | 1 | A sequence that specifies the flattest meridian as defined by the least power of curvature and longest radius of curvature. Only a single item shall be included in this sequence.
>Radius of Curvature | (0046,0075) | 1 | The radius of curvature of the principal meridians of the cornea, measured in mm.
>Keratometric Power | (0046,0076) | 1 | The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis | (0046,0077) | 1 | The meridian where the keratometric radius of curvature or power is measured, in degrees.

#### C.8.25.11 Subjective Refractive Measurements Module

Table C.8.25.11-1 defines the Attributes used to represent the subjective refractive measurements of a patient's eyes. Usually both eyes are measured, but sometimes just one.

Table C.8.25.11-1. Subjective Refractive Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Subjective Refraction Right Eye Sequence | (0046,0097) | 1C | A sequence that specifies the subjective refractive measurements of a patient's right eye. Only a single item shall be included in this sequence. Required if the right eye is measured.
>Include Table C.8.25.11-2 “Subjective Refractive Measurements Macro Attributes” |
Subjective Refraction Left Eye Sequence | (0046,0098) | 1C | A sequence that specifies the subjective refractive measurements of a patient's left eye. Only a single item shall be included in this sequence. Required if the left eye is measured.
>Include Table C.8.25.11-2 “Subjective Refractive Measurements Macro Attributes” |
Distance Pupillary Distance | (0046,0060) | 3 | Distance in mm between the pupils when the patient's object of regard is in the distance, as measured by a phoropter.
Near Pupillary Distance | (0046,0062) | 3 | Distance in mm between the pupils when the patient's object of regard is at near, as measured by a phoropter.
Intermediate Pupillary Distance | (0046,0063) | 3 | Distance in mm between the pupils when the patient's object of regard is at an intermediate distance, as measured by a phoropter.
Other Pupillary Distance | (0046,0064) | 3 | Distance in mm between the pupils when the patient's object of regard is at the distance specified in the attribute Add Other Sequence (0046,0102), as measured by a phoropter.

Table C.8.25.11-2 describes the attributes used for the Subjective Refractive Measurements Macro

Table C.8.25.11-2. Subjective Refractive Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Sphere Power | (0046,0146) | 1 | Refractive power of the eye that is the same in all meridians, measured at distance (optical infinity), in diopters.
Include Table C.8.25.6.1-1 “Cylinder Sequence Macro Attributes” |
Include Table C.8.25.6.2-1 “Prism Sequence Macro Attributes” |
Add Near Sequence | (0046,0100) | 1C | A sequence that specifies refractive measurements of the eye to correct for inability to focus at near while wearing the distance prescription. Only a single item shall be included in this sequence. Required if near point refraction is done.
>Add Power | (0046,0104) | 1 | Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.
>Viewing Distance | (0046,0106) | 3 | The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this sequence.
Add Intermediate Sequence | (0046,0101) | 1C | A sequence that specifies refractive measurements of the eye to correct for inability to focus at intermediate distance while wearing the distance prescription. Only a single item shall be included in this sequence. Required if intermediate point refraction is done.
>Add Power | (0046,0104) | 1 | Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.
>Viewing Distance | (0046,0106) | 3 | The distance, in cm, for testing visual acuity using the value of Add Power (0046,0104) in this sequence item.
Add Other Sequence | (0046,0102) | 1C | A sequence that specifies refractive measurements of the eye to correct for inability to focus at the below specified distance while wearing the distance prescription. Only a single item shall be included in this sequence. Required if refraction is done at less than distance (optical infinity), but at a distance other than "near" or "intermediate".
>Add Power | (0046,0104) | 1 | Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.
>Viewing Distance | (0046,0106) | 3 | The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this sequence item.

#### C.8.25.12 Visual Acuity Measurements Module

Table C.8.25.12-1 defines the Attributes used to represent the subjective measurements of a patient's visual acuity. Usually each eye is measured individually, but sometimes only one eye is measured; sometimes the visual acuity of both eyes working together is measured. The visual acuity may be measured uncorrected, or with various refractive corrections, such as best corrected distance, pinhole, habitual near, etc

Table C.8.25.12-1. Visual Acuity Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Viewing Distance Type | (0046,0125) | 1 | The viewing distance conditions under which a patient's vision was measured. Enumerated Values: DISTANCE NEAR INTERMEDIATE OTHER
Visual Acuity Type Code Sequence | (0046,0121) | 1 | A sequence that specifies the conditions under which a patient's vision was measured. Only a single item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes”. Defined CID 4216 “Ophthalmic Visual Acuity Type”. |
Background Color | (0046,0092) | 1 | The color of the background upon which optotypes are displayed for measurements of visual acuity. Defined Terms: RED GREEN WHITE REDGREENSPLIT
Optotype | (0046,0094) | 1 | The standardized test type (standard object of regard) used in measurements of visual acuity. Defined Terms: LETTERS NUMBERS PICTURES TUMBLING E LANDOLT C
Optotype Detailed Definition | (0046,0139) | 1C | Required if the Optotype (0046,0094) Attribute value is LETTERS or NUMBERS or PICTURES. Provides additional information to define what optotype was used. ### Note Letters, numbers, and pictures are commonly used but poorly standardized. The tumbling E and Landolt C are well defined.
Optotype Presentation | (0046,0095) | 1 | Specifies whether single or multiple optotypes were presented. Enumerated Values: SINGLE MULTIPLE
Visual Acuity Right Eye Sequence | (0046,0122) | 1C | A sequence that specifies the subjective measurement of a patient's visual acuity for the right eye. Only a single item shall be included in this sequence. Required if the right eye is measured.
>Include Table C.8.25.12-2 “Visual Acuity Measurements Macro Attributes” |
Visual Acuity Left Eye Sequence | (0046,0123) | 1C | A sequence that specifies the subjective measurements of a patient's visual acuity for the left eye. Only a single item shall be included in this sequence. Required if the left eye is measured.
>Include Table C.8.25.12-2 “Visual Acuity Measurements Macro Attributes” |
Visual Acuity Both Eyes Open Sequence | (0046,0124) | 3 | A sequence that specifies a patient's subjective visual acuity measurements with both eyes open. Only a single item is permitted in this sequence.
>Include Table C.8.25.12-2 “Visual Acuity Measurements Macro Attributes” |

Table C.8.25.12-2 describes the attributes for the Visual Acuity Measurements Macro.

Table C.8.25.12-2. Visual Acuity Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Decimal Visual Acuity | (0046,0137) | 1 | A patient's visual acuity specified in decimal. The value is derived from two values in a fraction where the numerator of the fraction is the nominal distance to the chart that the patient is reading. The denominator represents the line of smallest optotypes of which the patient can see more than half. ### Note Typical examples: reference standard is 1, severe vision loss is 0.1 See Annex RR “Ophthalmic Refractive Reports Use Cases (Informative)” in PS3.17 for guidance in converting Decimal Visual Acuity to other customarily used display notation such as 20/20 in the US and 6/6 in Britain.
Visual Acuity Modifiers | (0046,0135) | 3 | The first value is a positive or negative integer numeric value such as +1, +2, +3, 0, -1, -2, or -3 used to indicate that the patient missed letters on the line referenced, or saw additional letters on the next smaller line. The second value is a positive or negative integer numeric value such as +1, +2, +3, 0, -1, -2, or -3, which in combination with the first value indicates that the patient both saw additional letters on the next smaller line and missed letters on the line referenced. ### Note When the modifier values are zero, the values are not typically displayed to the user. See Annex RR “Ophthalmic Refractive Reports Use Cases (Informative)” in PS3.17 for guidance regarding significance of modifiers.

#### C.8.25.13 Ophthalmic Axial Measurements Series Module

Table C.8.25.13-1 specifies the Attributes that identify and describe general information about the Ophthalmic Axial Measurements Series.

Table C.8.25.13-1. Ophthalmic Axial Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the measurements in this Series. Enumerated Values: OAM See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.14 Ophthalmic Axial Measurements Module

Table C.8.25.14-1 defines the Attributes used to encode axial measurements of the eye made by an axial measurements device. This is typically done for both eyes, but may be for just one.

Table C.8.25.14-1. Ophthalmic Axial Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Axial Measurements Device Type | (0022,1009) | 1 | Describes the type of ophthalmic axial measurement acquisition device. Defined Terms: ULTRASOUND OPTICAL
Ophthalmic Ultrasound Method Code Sequence | (0022,1044) | 1C | The method used for obtaining axial measurements of the eye. Only a single Item shall be included in this sequence. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | >Defined CID 4230 “Ophthalmic Ultrasound Axial Measurements Type”
Anterior Chamber Depth Definition Code Sequence | (0022,1125) | 3 | The definition of anterior chamber depth for this instrument. Only a single Item is permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4239 “Anterior Chamber Depth Definition”
Ophthalmic Axial Measurements Right Eye Sequence | (0022,1007) | 1C | Axial measurements of a patient's right eye. Only a single Item shall be included in this sequence. Required if the right eye is measured.
>Include Table C.8.25.14-2 “Ophthalmic Axial Measurements Macro Attributes” |
>Include Table C.8.25.14-5 “Ophthalmic Axial Measurements Selected Macro Attributes” |
Ophthalmic Axial Measurements Left Eye Sequence | (0022,1008) | 1C | Axial measurements of a patient's left eye. Only a single Item shall be included in this sequence. Required if the left eye is measured.
>Include Table C.8.25.14-2 “Ophthalmic Axial Measurements Macro Attributes” |
>Include Table C.8.25.14-5 “Ophthalmic Axial Measurements Selected Macro Attributes” |

##### C.8.25.14.1 Ophthalmic Axial Measurements Macro

Table C.8.25.14-2 describes the attributes for the Ophthalmic Axial Measurements Macro.

Table C.8.25.14-2. Ophthalmic Axial Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Lens Status Code Sequence | (0022,1024) | 1 | Lens status of the eye. See Section C.8.25.14.1.1.1 for further explanation. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4231 “Lens Status”
Lens Status Description | (0022,1065) | 3 | A free form text description of Lens Status (0022,1024).
Vitreous Status Code Sequence | (0022,1025) | 1 | Status of the vitreous cavity. See Section C.8.25.14.1.1.2 for further explanation. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4232 “Vitreous Status”
Vitreous Status Description | (0022,1066) | 3 | A free form text description of Vitreous Status (0022,1025).
Pupil Dilated | (0022,000D) | 2 | Whether or not the patient's pupils were pharmacologically dilated for this acquisition Enumerated Values: YES NO If this tag is empty, no information is available.
Degree of Dilation | (0022,000E) | 2C | The degree of the dilation in mm. Required if the value of Pupil Dilated (0022,000D) is YES.
Mydriatic Agent Sequence | (0022,0058) | 2C | Information about the agent administered. Zero or more Items shall be included in this sequence. ### Note An empty sequence indicates that an agent was used for dilation, but the name was not entered. Required if the value of Pupil Dilated (0022,000D) is YES.
>Mydriatic Agent Code Sequence | (0022,001C) | 1 | The actual agent administered to dilate the pupil. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Baseline CID 4208 “Mydriatic Agent”.
>Mydriatic Agent Concentration | (0022,004E) | 3 | The concentration of the agent.
>Mydriatic Agent Concentration Units Sequence | (0022,0042) | 1C | Units of measure for the Mydriatic Agent Concentration. Only a single Item shall be included in this sequence. Required if Mydriatic Agent Concentration (0022,004E) is present.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4244 “Ophthalmic Agent Concentration Units”
Ophthalmic Axial Length Measurements Sequence | (0022,1050) | 1 | Measurements of the axial length of a patient's eye. One or more items shall be included in this sequence.
>Ophthalmic Axial Length Measurements Type | (0022,1010) | 1 | Identifies whether measuring the total axial length of the patient's eye or a segment of the eye for which a discrete measurement was obtained. Enumerated Values: TOTAL LENGTH the total axial length was taken with one measurement LENGTH SUMMATION a summation of segmental lengths that determine the total axial length SEGMENTAL LENGTH a segmental axial length
>Ophthalmic Axial Length Measurements Total Length Sequence | (0022,1210) | 1C | The axial length of a patient's eye, in mm. One or more items shall be included in this sequence. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is TOTAL LENGTH. See Section C.8.25.14.1.1.4 for further explanation.
>>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement acquired, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
>>Ophthalmic Axial Length Measurement Modified | (0022,1140) | 1 | Whether or not the clinician intervened to modify the output of the device. For example by forcing it to select a different peak in the display. Enumerated Values: YES NO
>>Referenced Ophthalmic Axial Length Measurement QC Image Sequence | (0022,1330) | 1 | Reference to the quality control image associated with this measurement. Only a single Item shall be included in this sequence. See Section C.8.25.14.1.1.6 for further explanation.
>>>Include Table C.8.25.16-6 “Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes” |
>>Include Table C.8.25.14-4 “Ophthalmic Axial Measurements Related Information Macro Attributes” |
>Ophthalmic Axial Length Measurements Length Summation Sequence | (0022,1212) | 1C | Axial length of a patient's eye, in mm, when it is calculated by summation of multiple segmental axial length measurements. One or more items shall be included in this sequence. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is LENGTH SUMMATION. See Section C.8.25.14.1.1.4 for further explanation.
>>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement acquired, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
>>Ophthalmic Axial Length Measurement Modified | (0022,1140) | 1 | Whether or not the clinician intervened to modify the output of the device. For example by forcing it to select a different peak in the display. Enumerated Values: YES NO
>>Referenced Ophthalmic Axial Length Measurement QC Image Sequence | (0022,1330) | 1 | Reference to the quality control image associated with this measurement. Only a single Item shall be included in this sequence. See Section C.8.25.14.1.1.6 for further explanation.
>>>Include Table C.8.25.16-6 “Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes” |
>>Ophthalmic Axial Length Measurements Segmental Length Sequence | (0022,1211) | 1 | Segmental axial length measurements of a patient's eye that contribute to an aggregate axial length measurement. One or more items shall be included in this sequence. See Section C.8.25.14.1.1.4 for further explanation.
>>>Include Table C.8.25.14-3 “Ophthalmic Axial Length Segmental Measurements Macro Attributes” |
>Ophthalmic Axial Length Measurements Segmental Length Sequence | (0022,1211) | 1C | Segmental axial length measurement of a patient's eye. Only a single Item shall be included in this sequence. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is SEGMENTAL LENGTH. See Section C.8.25.14.1.1.4 for further explanation.
>>Include Table C.8.25.14-3 “Ophthalmic Axial Length Segmental Measurements Macro Attributes” |

###### C.8.25.14.1.1 Ophthalmic Axial Measurements Macro Attribute Descriptions

###### C.8.25.14.1.1.1 Lens Status Code Sequence

Lens Status Code Sequence (0022,1024) refers to either the natural lens of the eye (phakic), or various types of lens implants inserted in cataract surgery, or lack of a lens in the eye (aphakic).

###### C.8.25.14.1.1.2 Vitreous Status Code Sequence

Vitreous Status Code Sequence (0022,1025) refers to either the natural status of the vitreous cavity (vitreous only) or to various possible states after vitreous surgery.

###### C.8.25.14.1.1.3 Ophthalmic Axial Length

If Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND, the Ophthalmic Axial Length (0022,1019) measurement is taken from the anterior vertex of the cornea to the anterior surface of the retina (internal limiting membrane).

If Ophthalmic Axial Measurements Device Type (0022,1009) is OPTICAL, the Ophthalmic Axial Length (0022,1019) measurement is taken from the anterior vertex of the cornea to the level of the photoreceptors in the retina and compensated to adjust for the thickness of the retina to mimic the ultrasound technique.

This difference is an inherent property of the measurement method. Since optical devices measure to retinal pigment epithelium and ultrasound devices measure to internal limiting membrane, the difference must be subtracted to obtain comparable results for use in intraocular lens calculation formulas. The difference is the thickness of the retina, which has been determined empirically and varies with the axial length of the eye.

The intent is to measure along the patient's visual axis.

###### C.8.25.14.1.1.4 Ophthalmic Axial Length Measurements Segment Name Code Sequence

When the acquisition device type is ultrasound, the Ophthalmic Axial Length (0022,1019) may represent distance calculated using a single time value and an average presumed velocity for the entire eye. Alternatively it may represent the sum of multiple segmental axial length measurements with each distance value calculated using a different time value and a presumed velocity specific to that segment of the eye.

When the acquisition device type is optical, the whole length can be measured instead of measuring and summing up different segments of the eye. Nevertheless, optical axial measurement devices can also measure segments of the eye independently(e.g., the Anterior Chamber depth).

Each segment of the eye that is measured shall be identified by the Ophthalmic Axial Length Measurements Segment Name Code Sequence (0022,1101).

###### C.8.25.14.1.1.5 Observer Type

For attribute Observer Type (0040,A084), Ultrasound axial length measurement devices take many measurements in rapid sequence. The machine can be set to select a good quality measurement automatically, or it can be set so that the user presses a footswitch when he/she sees a quality measurement based on the graphical display.

###### C.8.25.14.1.1.6 Referenced Ophthalmic Axial Length Measurement QC Image Sequence

The attribute Referenced Ophthalmic Axial Length Measurement QC Image Sequence (0022,1330) references a quality control image that is a secondary capture of the presentation of a one dimensional waveform produced when performing ophthalmic axial measurements. It is acquired by the modality creating the ophthalmic axial measurements. The purpose of these images is to judge the quality of an axial length measurement for use in calculating the power of intraocular lens to place in a patient's eye in cataract surgery. The image is used for quality control and not for diagnostic purposes. See PS3.17.

The SOP Instance for the quality control image will meet the following requirements:

- Frame Increment Pointer (0028,0009) is set to 00182002 = sequencing by Frame Label Vector (0018,2002).

  ### Note

  The frame number is the recommended value for the label.

- The attribute Reference Instance Sequence (0008,114A) is conveyed and only a single item is used. The item in Reference Instance Sequence (0008,114A) contains the value "1.2.840.10008.5.1.4.1.1.78.7" = (this SOP Class) for attribute Referenced SOP Class UID (0008,0050) and attribute Reference SOP Instance UID (0008,1155) will reference this measurement SOP Instance.

- Burned In Annotation (0028,0301) is set to NO.

  The attribute Burned In Annotation (0028,0301) defines whether patient demographics have been burned into the image. This attribute does not prohibit non-demographic burned in annotation, such as position of gates, for image or waveform annotations that are very important to a user. Such annotations are expected to be conveyed and displayed.

- Quality Control Image (0028,0300) is set to YES.

##### C.8.25.14.2 Ophthalmic Axial Length Segmental Measurements Macro

Table C.8.25.14-3 describes the attributes for the Ophthalmic Axial Length Segmental Measurements Macro.

Table C.8.25.14-3. Ophthalmic Axial Length Segmental Measurements Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
Ophthalmic Axial Length Measurement Modified | (0022,1140) | 1 | Whether or not the clinician intervened to modify the output of the device. For example by forcing it to select a different peak in the display. Enumerated Values: YES NO
Ophthalmic Axial Length Measurements Segment Name Code Sequence | (0022,1101) | 1 | The name of the segment measured. See Section C.8.25.14.1.1.4 for further explanation. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4233 “Ophthalmic Axial Length Measurements Segment Names”
Include Table C.8.25.14-4 “Ophthalmic Axial Measurements Related Information Macro Attributes” |

##### C.8.25.14.3 Ophthalmic Axial Measurements Related Information Macro

Table C.8.25.14-4 describes the attributes for the Ophthalmic Axial Measurements Related Information Macro.

Table C.8.25.14-4. Ophthalmic Axial Measurements Related Information Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ultrasound Ophthalmic Axial Length Measurements Sequence | (0022,1220) | 1C | Related information about an axial length measurement being performed on an ultrasound device. Only a single Item shall be included in this sequence. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND.
>Ophthalmic Axial Length Velocity | (0022,1059) | 1 | The sound velocity used in calculating the Ophthalmic Axial Length Measurement Value (0022,1019), in m/sec.
>Observer Type | (0040,A084) | 1 | Method used to select which acquired axial length measurement values are kept. Enumerated Values: PSN Person; manually selected DEV Device; automatically selected See Section C.8.25.14.1.1.5 for further explanation.
>Ophthalmic Axial Length Data Source Code Sequence | (0022,1150) | 1 | Source of the value recorded in Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>Ophthalmic Axial Length Data Source Description | (0022,1159) | 3 | A free text description of the axial length measurement data source.
Optical Ophthalmic Axial Length Measurements Sequence | (0022,1225) | 1C | Related information about an axial length measurement being performed on an optical device. Only a single Item shall be included in this sequence. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is OPTICAL.
>Signal to Noise Ratio | (0022,1155) | 1C | The ratio of signal power to the background noise power (Psignal / Pnoise). Required if Ophthalmic Axial Length Measurements Type (0022,1010) is TOTAL LENGTH. May be present otherwise.
>Ophthalmic Axial Length Data Source Code Sequence | (0022,1150) | 1 | The source of the value in Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>Ophthalmic Axial Length Data Source Description | (0022,1159) | 3 | A free text description of the axial length measurement data source.

##### C.8.25.14.4 Ophthalmic Axial Measurements Selected Macro

Table C.8.25.14-5 describes the attributes for the Ophthalmic Axial Measurements Selected Macro. These are the attributes of the Ophthalmic Axial Length (0022,1019) selected for use in IOL calculations.

Table C.8.25.14-5. Ophthalmic Axial Measurements Selected Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ultrasound Selected Ophthalmic Axial Length Sequence | (0022,1230) | 1C | Information related to the selected axial length measurement of the patient's eye when acquired on an ultrasound device. Only a single Item shall be included in this sequence. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND.
>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.4 for further explanation.
>Ophthalmic Axial Length Selection Method Code Sequence | (0022,1250) | 1 | Method used to derive the value recorded in Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes”. Defined CID 4241 “Ophthalmic Axial Length Selection Method”. |
>Referenced Ophthalmic Axial Length Measurement QC Image Sequence | (0022,1330) | 1 | References to the quality control image associated with this measurement. Only a single Item shall be included in this sequence. See Section C.8.25.14.1.1.6 for further explanation.
>>Include Table C.8.25.16-6 “Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes” |
>Ophthalmic Axial Length Quality Metric Sequence | (0022,1262) | 1 | Information about the quality metric applied to Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table C.8.25.14-6 “Ophthalmic Axial Length Quality Metric Macro Attributes” |
>Selected Segmental Ophthalmic Axial Length Sequence | (0022,1257) | 1C | Segmental axial length measurements of a patient's eye that are summed to derive a total axial length for the eye. One or more items shall be included in this sequence. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is LENGTH SUMMATION.
>>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
>>Ophthalmic Axial Length Measurements Segment Name Code Sequence | (0022,1101) | 1 | Name of the segment measured. See Section C.8.25.14.1.1.4 for further explanation. Only a single Item shall be included in this sequence.
>>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4233 “Ophthalmic Axial Length Measurements Segment Names”
Optical Selected Ophthalmic Axial Length Sequence | (0022,1255) | 1C | Information related to the selected axial length measurement(s) of the patient's eye when acquired on an optical device. One or more items shall be included in this sequence. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is OPTICAL.
>Selected Total Ophthalmic Axial Length Sequence | (0022,1260) | 1C | Total axial length measurement selected for the patient's eye. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is TOTAL LENGTH. Only a single Item shall be included in this sequence.
>>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
>>Referenced Ophthalmic Axial Length Measurement QC Image Sequence | (0022,1330) | 1 | Reference to the quality control image associated with this measurement. Only a single Item shall be included in this sequence. See Section C.8.25.14.1.1.6 for further explanation.
> >>Include Table C.8.25.16-6 “Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes” |
>>Ophthalmic Axial Length Quality Metric Sequence | (0022,1262) | 1 | Information about the quality metric applied to Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>>Include Table C.8.25.14-6 “Ophthalmic Axial Length Quality Metric Macro Attributes” |
>Selected Segmental Ophthalmic Axial Length Sequence | (0022,1257) | 1C | Segmental axial length measurement(s) selected for the patient's eye. One or more items shall be included in this sequence. Required if Ophthalmic Axial Length Measurements Type (0022,1010) is SEGMENTAL LENGTH. May be present otherwise.
>>Ophthalmic Axial Length Measurements Segment Name Code Sequence | (0022,1101) | 1 | Name of the segment measured. See Section C.8.25.14.1.1.4 for further explanation. Only a single Item shall be included in this sequence.
>>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4233 “Ophthalmic Axial Length Measurements Segment Names”
>>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length measurement, in mm. The type of measurement is specified in the Ophthalmic Axial Length Measurements Type (0022,1010). See Section C.8.25.14.1.1.3 and Section C.8.25.14.1.1.4 for further explanation.
>>Referenced Ophthalmic Axial Length Measurement QC Image Sequence | (0022,1330) | 3 | Reference to the quality control image associated with this measurement. Only a single Item is permitted in this sequence. See Section C.8.25.14.1.1.6 for further explanation.
>>>Include Table C.8.25.16-6 “Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes” |
>>Ophthalmic Axial Length Quality Metric Sequence | (0022,1262) | 3 | Information about the quality metric applied to Ophthalmic Axial Length (0022,1019). Only a single Item is permitted in this sequence.
>>>Include Table C.8.25.14-6 “Ophthalmic Axial Length Quality Metric Macro Attributes” |

##### C.8.25.14.5 Ophthalmic Axial Measurements Quality Metric Macro

Table C.8.25.14-6 describes the attributes for the Ophthalmic Axial Length Quality Metric Macro.

Table C.8.25.14-6. Ophthalmic Axial Length Quality Metric Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Concept Name Code Sequence | (0040,A043) | 1 | Type of metric used to evaluate the quality of the ophthalmic axial length. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4243 “Ophthalmic Axial Length Quality Metric Type”
Numeric Value | (0040,A30A) | 1 | Value for quality metric applied to axial length values.
Measurement Units Code Sequence | (0040,08EA) | 1 | Units of Numeric Value (0040,A30A). Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 82 “Units of Measurement”.

#### C.8.25.15 Intraocular Lens Calculations Series Module

Table C.8.25.15-1 specifies the Attributes that identify and describe general information about the Intraocular Lens Calculations Series.

Table C.8.25.15-1. Intraocular Lens Calculations Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Specific equipment on which the software that performed the calculations in this Series resides. Enumerated Values: IOL See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.25.16 Intraocular Lens Calculations Module

Table C.8.25.16-1 defines the Attributes used to calculate the power of an intraocular lens to be placed in a patient's eye. This is typically done for both eyes for comparison, but may be for just one eye. Values used may be measurements acquired using the axial length measurements device, manually entered, or derived from a referenced SOP class or other data source.

Table C.8.25.16-1. Intraocular Lens Calculations Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Intraocular Lens Calculations Right Eye Sequence | (0022,1300) | 1C | Calculations of intraocular lens power for a patient's right eye. One or more Items shall be included in this sequence. Required if the device calculated intraocular lens power for the right eye.
>Include Table C.8.25.16-2 “Intraocular Lens Calculations Macro Attributes” |
Intraocular Lens Calculations Left Eye Sequence | (0022,1310) | 1C | Calculations of intraocular lens power for a patient's left eye. One or more Items shall be included in this sequence. Required if the device calculated intraocular lens power for the left eye.
>Include Table C.8.25.16-2 “Intraocular Lens Calculations Macro Attributes” |

##### C.8.25.16.1 Intraocular Lens Calculations Module Attributes

###### C.8.25.16.1.1 Referenced SOP Sequence

Data in an IOL Calculations SOP Instance will frequently be gathered from other SOP instances, such as ophthalmic axial measurements SOP Instances or refractive measurements SOP Instances. If this occurs, a reference to the SOP instances is desired in attribute Referenced SOP Sequence (0008,1199).

##### C.8.25.16.2 Intraocular Lens Calculations Macro

Table C.8.25.16-2 describes the attributes for the Intraocular Lens Calculations Macro.

Table C.8.25.16-2. Intraocular Lens Calculations Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Target Refraction | (0022,1037) | 1 | The desired postoperative refractive error, in diopters.
Refractive Procedure Occurred | (0022,1039) | 2 | Whether or not a patient has had refractive surgery. Enumerated Values: YES NO
Refractive Surgery Type Code Sequence | (0022,1040) | 2C | Type of refractive surgery a patient has had. Zero or more Items shall be included in this sequence. Required if the value of Refractive Procedure Occurred (0022,1039) is YES.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4234 “Refractive Surgery Types”
Refractive Error Before Refractive Surgery Code Sequence | (0022,1103) | 2C | The patient's refractive error before any of the refractive surgeries listed in Refractive Surgery Type Code Sequence (0022,1040) were performed. Zero or one Item shall be included in this sequence. Required if the value of Refractive Procedure Occurred (0022,1039) is YES.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4238 “Refractive Error Types”
Corneal Size | (0046,0046) | 3 | The horizontal diameter measurement of the cornea, in mm.
Lens Thickness Sequence | (0022,1127) | 3 | Lens thickness value and source. Only a single Item is permitted in this sequence.
>Lens Thickness | (0022,1130) | 1 | The value for axial length of the lens in a patient's eye, in mm.
>Source of Lens Thickness Data Code Sequence | (0022,1132) | 1 | Source of the value of Lens Thickness (0022,1130). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>Referenced SOP Sequence | (0008,1199) | 1C | SOP Instance that is relevant to the interpretation of this SOP Instance. Only a single Item shall be included in this sequence. See Section C.8.25.16.1.1 for further explanation. Required if Source of Lens Thickness Data Code Sequence (0022,1132) contains an item with the value (111782, DCM, "Axial Measurements SOP Instance").
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Anterior Chamber Depth Sequence | (0022,1128) | 3 | Anterior chamber depth value and source. Only a single Item is permitted in this sequence.
>Anterior Chamber Depth | (0022,1131) | 1 | The value for axial length of the anterior chamber, in mm.
>Source of Anterior Chamber Depth Data Code Sequence | (0022,1133) | 1 | Source of the value of Anterior Chamber Depth (0022,1131). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>Referenced SOP Sequence | (0008,1199) | 1C | SOP Instance that is relevant to the interpretation of this SOP Instance. Only a single Item shall be included in this sequence. See Section C.8.25.16.1.1 for further explanation. Required if Source of Anterior Chamber Depth Data Code Sequence (0022,1133) contains an item with the value (111782, DCM, "Axial Measurements SOP Instance").
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Refractive State Sequence | (0022,001B) | 2 | Refractive state of the imaged eye at the time of acquisition. Zero or one Item shall be included in this sequence.
>Spherical Lens Power | (0022,0007) | 1 | Sphere value in diopters.
>Cylinder Lens Power | (0022,0008) | 1 | Cylinder value in diopters.
>Cylinder Axis | (0022,0009) | 1 | Axis value in degrees.
>Source of Refractive Measurements Sequence | (0022,1134) | 1 | Refractive measurements source. Only a single Item shall be included in this sequence.
>>Source of Refractive Measurements Code Sequence | (0022,1135) | 1 | Source of values in Refractive State Sequence (0022,101B). Only a single Item shall be included in this sequence.
>>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>>Referenced SOP Sequence | (0008,1199) | 1C | SOP Instances that are relevant to the interpretation of this SOP Instance. One or more items shall be included in this sequence. See Section C.8.25.16.1.1 for further explanation. Required if Source of Refractive Measurements Code Sequence (0022,1135) contains an item with the value (111783, DCM, "Refractive Measurements SOP Instance").
>>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Include Table C.8.25.16-3 “Keratometry Macro Attributes” |
IOL Formula Code Sequence | (0022,1028) | 1 | Formula used to calculate IOL power. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4236 “IOL Calculation Formula”
IOL Formula Detail | (0022,1029) | 3 | A free form text description of the of the IOL Formula Code Sequence (0022,1028) (e.g., a reference to the mathematical equation).
Include Table C.8.25.16-4 “IOL Ophthalmic Axial Length Macro Attributes” |
Include Table C.8.25.16-5 “Calculated IOL Macro Attributes” |

##### C.8.25.16.3 Keratometry Macro

Table C.8.25.16-3 describes the attributes for the Keratometry Macro.

Table C.8.25.16-3. Keratometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Steep Keratometric Axis Sequence | (0046,0074) | 1 | Steepest meridian as defined by the greatest power of curvature and shortest radius of curvature. Only a single Item shall be included in this sequence.
>Radius of Curvature | (0046,0075) | 1 | The radius of curvature of the principal meridians of the cornea, measured in mm.
>Keratometric Power | (0046,0076) | 2 | The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis | (0046,0077) | 2 | The meridian where the keratometric radius of curvature or power is measured, in degrees.
Flat Keratometric Axis Sequence | (0046,0080) | 1 | Flattest meridian as defined by the least power of curvature and longest radius of curvature. Only a single Item shall be included in this sequence.
>Radius of Curvature | (0046,0075) | 1 | The radius of curvature of the principal meridians of the cornea, measured in mm.
>Keratometric Power | (0046,0076) | 2 | The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis | (0046,0077) | 2 | The meridian where the keratometric radius of curvature or power is measured, in degrees.
Keratometry Measurement Type Code Sequence | (0022,1096) | 2 | Descriptors relevant to keratometry data. Zero or one Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4235 “Keratometry Descriptors”
Keratometer Index | (0022,1033) | 2 | The translation factor specific to each keratometer that derives a number for power from the measured radius of curvature of the cornea.

##### C.8.25.16.4 Iol Ophthalmic Axial Length Macro

Table C.8.25.16-4 describes the attributes for the IOL Ophthalmic Axial Length Macro.

Table C.8.25.16-4. IOL Ophthalmic Axial Length Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Axial Length Sequence | (0022,1012) | 1 | Axial length value and source that was used in calculation of IOL power. Only a single Item shall be included in this sequence.
>Ophthalmic Axial Length | (0022,1019) | 1 | The axial length of a patient's eye, in mm, that was used in calculation of IOL power.
>Ophthalmic Axial Length Selection Method Code Sequence | (0022,1250) | 1 | Method used to select the value recorded in Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4241 “Ophthalmic Axial Length Selection Method”
>Source of Ophthalmic Axial Length Code Sequence | (0022,1035) | 1 | Source of the value of Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4240 “Ophthalmic Measurement Or Calculation Data Source”
>Referenced SOP Sequence | (0008,1199) | 1C | SOP Instances that are relevant to the interpretation of this SOP Instance. One or more items shall be included in this sequence. See Section C.8.25.16.1.1 for further explanation. Required if Source of Ophthalmic Axial Length Code Sequence (0022,1035) contains an item with the value (111782, DCM, "Axial Measurements SOP Instance").
>>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Ophthalmic Ultrasound Method Code Sequence | (0022,1044) | 1C | Method used for obtaining axial measurements of the eye. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4230 “Ophthalmic Ultrasound Axial Measurements Type”

##### C.8.25.16.5 Calculated Iol Macro

Table C.8.25.16-5 describes the attributes for the Calculated IOL Macro.

Table C.8.25.16-5. Calculated IOL Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
IOL Manufacturer | (0022,1093) | 1 | Name of the manufacturer that produced the lens.
Implant Name | (0022,1095) | 1 | The (product) name of the lens.
Lens Constant Sequence | (0022,1092) | 1 | Constants used in calculation of intraocular lens power. These constants are a characteristic of the model of intraocular lens being considered for use in cataract surgery. One or more Items shall be included in this sequence.
>Concept Name Code Sequence | (0040,A043) | 1 | Constant type used in calculation of intraocular lens power. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4237 “Lens Constant Type”
>Numeric Value | (0040,A30A) | 1 | The value of the constant used.
IOL Power Sequence | (0022,1090) | 1 | Information needed to select the intraocular lens power for cataract surgery. One or more Items shall be included in this sequence.
>IOL Power | (0022,1053) | 1 | The intraocular lens power, in diopters.
>Predicted Refractive Error | (0022,1054) | 1 | The predicted postoperative refractive error (i.e., amount of near or far sightedness), in diopters.
>Implant Part Number | (0022,1097) | 2 | The (product) identifier of the lens.
IOL Power for Exact Emmetropia | (0022,1121) | 2 | The IOL power that would be required to achieve exact emmetropia, or no need for glasses at distance after surgery, in diopters.
IOL Power for Exact Target Refraction | (0022,1122) | 2 | The IOL power that would be required to exactly achieve Target Refraction (0022,1037), in diopters.

##### C.8.25.16.6 Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro

Table C.8.25.16-6 describes the attributes for the Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro

Table C.8.25.16-6. Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Referenced SOP Class UID | (0008,1150) | 1 | Uniquely identifies the referenced SOP Class. Enumerated Values: 1.2.840.10008.5.1.4.1.1.7.2 Multi-frame Grayscale Byte Secondary Capture Image Storage 1.2.840.10008.5.1.4.1.1.7.4 Multi-frame True Color Secondary Capture Image Storage
Referenced SOP Instance UID | (0008,1155) | 1 | Uniquely identifies the referenced SOP Instance.
Referenced Frame Number | (0008,1160) | 1 | Identifies the frame number within the Referenced SOP Instance to which the reference applies. The first frame shall be denoted as frame number 1. Only a single value shall exist. ### Note This Attribute is a multi-value field but for this Macro it can only contain one value.

### C.8.26 Visual Field Static Perimetry Measurements Modules

#### C.8.26.1 Visual Field Static Perimetry Measurements Series Module

Table C.8.26.1-1 specifies the Attributes that identify and describe general information about the Visual Field Static Perimetry Measurements Series.

Table C.8.26.1-1. Visual Field Static Perimetry Measurements Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the measurements in this Series. Enumerated Values: OPV See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Request Attributes Sequence | (0040,0275) | 3 | Sequence that contains attributes from the Imaging Service Request. One or more Items are permitted in this sequence.
>Include Table 10-9 “Request Attributes Macro Attributes” | In this Module Reason for Requested Procedure Code Sequence (0040,100A) has the Defined CID 4256 “Visual Field Procedure Modifier”. ### Note Reason for Requested Procedure Code Sequence (0040,100A) may be used to provide whether the test in the Series was taken for screening or diagnostic (quantitative) purposes. In this Module Scheduled Protocol Code Sequence (0040,0008) has the Defined CIDs 4250 and 4251. ### Note Scheduled Protocol Code Sequence (0040,0008) may be used to provide test pattern and test strategy. No Baseline CIDs are defined for other Attributes.
Include Table 10-16 “Performed Procedure Step Summary Macro Attributes” | In this Module attribute Performed Protocol Code Sequence (0040,0260) is Type 1 and the Defined CID 4250 “Visual Field Static Perimetry Test Patterns” and CID 4251 “Visual Field Static Perimetry Test Strategies”. ### Note Performed Protocol Code Sequence (0040,0260) is used to provide test pattern and test strategy. In this Module attribute Protocol Context Sequence (0040,0440) is Type 1 and the Defined CID 4256 “Visual Field Procedure Modifier”. ### Note Protocol Context Sequence (0040,0440) is used to provide whether the test in the Series were taken for screening or diagnostic purposes. No Baseline CIDs are defined for other Attributes.

#### C.8.26.2 Visual Field Static Perimetry Test Parameters Module

Table C.8.26.2-1 defines the Attributes used to represent the parameters used during a patient's visual field test.

Table C.8.26.2-1. Visual Field Static Perimetry Test Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Visual Field Horizontal Extent | (0024,0010) | 1 | The maximum horizontal angular subtend (diameter or width) of the tested visual field, in degrees.
Visual Field Vertical Extent | (0024,0011) | 1 | The maximum vertical angular subtend (diameter or height) of the tested visual field, in degrees.
Visual Field Shape | (0024,0012) | 1 | The shape of the visual field tested. Defined Terms: RECTANGLE CIRCLE ELLIPSE
Screening Test Mode Code Sequence | (0024,0016) | 1C | Mode used to determine how the starting luminance values and expected thresholds are chosen. Only a single Item shall be included in this sequence. Required if Content Item Modifier Sequence (0040,0441) within Performed Protocol Code Sequence (0040,0260) contains an item with the value (R-42453, SRT, "Screening"). May be present otherwise.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4252 “Visual Field Static Perimetry Screening Test Modes”
Maximum Stimulus Luminance | (0024,0018) | 1 | Maximum luminance of stimulus, in candelas per square meter (cd/m²).
Background Luminance | (0024,0020) | 1 | Background luminance of the device, in candelas per square meter (cd/m²). ### Note This value is easily convertible to apostilb, which is used only in perimetry and is not a standardized unit.
Stimulus Color Code Sequence | (0024,0021) | 1 | Color of light stimulus presented to the patient. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4255 “Visual Field Illumination Color”
Background Illumination Color Code Sequence | (0024,0024) | 1 | Color of the background illumination of the visual field device. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4255 “Visual Field Illumination Color”
Stimulus Area | (0024,0025) | 1 | Area of light stimulus presented to the patient, in degrees squared.
Stimulus Presentation Time | (0024,0028) | 1 | The duration of time that a light stimulus is presented to a patient per each individual test point, in milliseconds. ### Note This time is the same for each stimulus presentation.

#### C.8.26.3 Visual Field Static Perimetry Test Reliability Module

Table C.8.26.3-1 defines the Attributes used to represent the test reliability parameters determined during a patient's visual field test.

Table C.8.26.3-1. Visual Field Static Perimetry Test Reliability Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Fixation Sequence | (0024,0032) | 1 | The patient's gaze stability information during the visual field test. Only a single Item shall be included in this sequence.
>Fixation Monitoring Code Sequence | (0024,0033) | 1 | The device strategy used to monitor the patient's fixation. One or more Items shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4253 “Visual Field Static Perimetry Fixation Strategy”.
>Fixation Checked Quantity | (0024,0035) | 1C | The number of times that the patient's gaze fixation is checked. Required if Fixation Monitoring Code Sequence (0024,0033) contains an item with the value (111844, DCM, "Blind Spot Monitoring") or (111845, DCM, "Macular Fixation Testing"). May be present otherwise.
>Patient Not Properly Fixated Quantity | (0024,0036) | 1C | The number of times the patient's gaze is not properly fixated. Required if Fixation Monitoring Code Sequence (0024,0033) contains an item with the value (111844, DCM, "Blind Spot Monitoring") or (111845, DCM, "Macular Fixation Testing"). May be present otherwise.
>Excessive Fixation Losses Data Flag | (0024,0039) | 1 | Whether the device was able to determine excessive fixation losses. Enumerated Values: YES NO
>Excessive Fixation Losses | (0024,0040) | 1C | The number of fixation losses is outside of implementation-specific limits. Enumerated Values: YES NO Required if Excessive Fixation Losses Data Flag (0024,0039) is YES.
Visual Field Catch Trial Sequence | (0024,0034) | 1 | The reliability of the patient's responses to the visual field test. Only a single Item shall be included in this sequence.
>Catch Trials Data Flag | (0024,0055) | 1 | Whether catch trials data were performed. Enumerated Values: YES NO
>Negative Catch Trials Quantity | (0024,0048) | 1C | Total number of times the patient's visual attention was tested using stimuli brighter than previously seen luminance (negative catch trials). Required if Catch Trials Data Flag (0024,0055) is YES.
>False Negatives Quantity | (0024,0050) | 1C | Total number of stimuli that were not seen by the patient but were previously seen at a lower luminance earlier in the visual field test (false negatives). Required if Catch Trials Data Flag (0024,0055) is YES.
>False Negatives Estimate Flag | (0024,0045) | 1 | Whether the device was able to estimates false negatives. Enumerated Values: YES NO
>False Negatives Estimate | (0024,0046) | 1C | Estimated percentage of all stimuli that were not seen by the patient but were previously seen at a lower luminance earlier in the visual field test (false negative responses), as percent. Required if False Negatives Estimate Flag (0024,0045) is YES.
>Excessive False Negatives Data Flag | (0024,0051) | 1 | Whether the device was able to determine excessive false negatives. Enumerated Values: YES NO
>Excessive False Negatives | (0024,0052) | 1C | The false negative estimate is outside of implementation-specific limits. Enumerated Values: YES NO Required if Excessive False Negatives Data Flag (0024,0051) is YES.
>Positive Catch Trials Quantity | (0024,0056) | 1C | The total number of times the device behaved as if it was going to present a visual stimulus but did not actually present the stimulus (positive catch trials). Required if Catch Trials Data Flag (0024,0055) is YES.
>False Positives Quantity | (0024,0060) | 1C | The total number of patient responses that occurred at a time when no visual stimulus was present (false positive responses). Required if Catch Trials Data Flag (0024,0055) is YES.
>False Positives Estimate Flag | (0024,0053) | 1 | Whether the device was able to estimate false positives. Enumerated Values: YES NO
>False Positives Estimate | (0024,0054) | 1C | Estimated percentage of all patient responses that occurred at a time when no visual stimulus was present (false positive responses), as percent. Required if False Positives Estimate Flag (0024,0053) is YES.
>Excessive False Positives Data Flag | (0024,0061) | 1 | Whether the device was able to determine excessive false positives. Enumerated Values: YES NO
>Excessive False Positives | (0024,0062) | 1C | The false positive estimate is outside of implementation-specific limit. Enumerated Values: YES NO Required if Excessive False Positives Data Flag (0024,0061) is YES.
Stimuli Retesting Quantity | (0024,0042) | 3 | Total number of times in the course of a visual field exam that any location had to be retested at the same magnitude. ### Note An example is that the patient received 20 stimuli and blinked twice, therefore need to present the stimuli two additional times in which case the value is 2.
Patient Reliability Indicator | (0024,0069) | 3 | Vendor implementation specific text to provide an analysis and/or summary of patient reliability indicator/indices.
Comments on Patient's Performance of Visual Field | (0024,0044) | 3 | Operator's (test administrator) subjective comment on patient's performance.
Visual Field Test Reliability Global Index Sequence | (0024,0317) | 3 | Information about various visual field indices related to test reliability. One or more Items are permitted in this sequence.
>Include Table C.8.26.3-2 “Ophthalmic Visual Field Global Index Macro Attributes” |

##### C.8.26.3.1 Ophthalmic Visual Field Global Index Macro

Table C.8.26.3-2 describes the attributes for the Ophthalmic Visual Field Global Index Macro.

Table C.8.26.3-2. Ophthalmic Visual Field Global Index Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Data Observation Sequence | (0024,0325) | 1 | Information about various visual field global indexes. Only a single Item shall be included in this sequence.
>Include Table 10-2 “Content Item Macro Attributes Description” | Value Type (0040,A040) shall be NUMERIC or CODE. Concept Name Code Sequence (0040,A043) shall use CID 4257 “Visual Field Global Index Name”. Concept Code Sequence (0040,A168) shall use CID 4254 “Visual Field Static Perimetry Test Analysis Results”.
Index Normals Flag | (0024,0338) | 1 | Whether normative data exists for this index. Enumerated Values: YES NO
Index Probability Sequence | (0024,0344) | 1C | Probability value and software algorithm used to provide the index. Only a single Item shall be included in this sequence. Required if Index Normals Flag (0024,0338) is YES.
>Index Probability | (0024,0341) | 1 | Probability for the index value within the normal population, in percent.
>Include Table 10-19 “Algorithm Identification Macro Attributes” |

#### C.8.26.4 Visual Field Static Perimetry Test Measurements Module

Table C.8.26.4-1 defines the Attributes used to represent the test measurement values determined during a patient's visual field test.

Table C.8.26.4-1. Visual Field Static Perimetry Test Measurements Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Measurement Laterality | (0024,0113) | 1 | Laterality of body part (eye) examined. See Section C.8.26.4.1.1 for further explanation. Enumerated Values: R right L left B both left and right together ### Note This Attribute is mandatory, in order to ensure that measurements may be positioned correctly relative to one another for display. ### Note Laterality (0020,0060) is a Series level Attribute and must be the same for all Measurements in the Series, hence it must be absent if multiple instances from different eyes are encoded.
Presented Visual Stimuli Data Flag | (0024,0037) | 1 | Whether the device was able to determine presented visual stimuli. Enumerated Values: YES NO
Number of Visual Stimuli | (0024,0038) | 1C | The total number of visual stimuli presented to the patient. This includes the number of stimuli repetitions. Required if Presented Visual Stimuli Data Flag (0024,0037) is YES.
Visual Field Test Duration | (0024,0088) | 1 | Total time the visual field machine was actively presenting visual stimuli to patient, in seconds.
Foveal Sensitivity Measured | (0024,0086) | 1 | Whether foveal sensitivity was measured. Enumerated Values: YES NO
Foveal Sensitivity | (0024,0087) | 1C | Foveal Sensitivity is the reciprocal of foveal threshold (1/foveal threshold), in dB. Foveal Threshold is the minimum amount of luminance increment on a uniform background that can be detected by the patient at coordinates 0,0 (relative to the center of the patient's fixation). See Section C.8.26.4.1.2 for further explanation. Required if the value for Foveal Sensitivity Measured (0024,0086) is YES.
Foveal Point Normative Data Flag | (0024,0117) | 1 | Existence of normative data base for the foveal point sensitivity. Enumerated Values: YES NO
Foveal Point Probability Value | (0024,0118) | 1C | The percentile of the foveal point sensitivity within an age corrected normal visual field, in percent. Required if the value for Foveal Sensitivity Measured (0024,0086) is YES and Foveal Point Normative Data Flag (0024,0117) is YES.
Screening Baseline Measured | (0024,0120) | 1 | Whether visual field screening baseline was measured. Enumerated Values: YES NO
Screening Baseline Measured Sequence | (0024,0122) | 1C | Information about the starting luminance screening values. One or more Items shall be included in this sequence. Required if the value for Screening Baseline Measured (0024,0120) is YES.
>Screening Baseline Type | (0024,0124) | 1 | Method used to determine starting luminance screening values. Enumerated Values: CENTRAL PERIPHERAL
>Screening Baseline Value | (0024,0126) | 1 | Visual Field screening baseline value, in dB.
Blind Spot Localized | (0024,0106) | 1 | Whether the blind spot was measured. Enumerated Values: YES NO
Blind Spot X-Coordinate | (0024,0107) | 1C | The horizontal coordinate of the patient's blind spot relative to the center of the patient's fixation, in degrees, such that toward the right is positive. Required if the value for Blind Spot Localized (0024,0106) is YES. See Section C.8.26.4.1.3 for further explanation.
Blind Spot Y-Coordinate | (0024,0108) | 1C | The vertical coordinate of the patient's blind spot relative to the center of the patient fixation, in degrees, such that up is positive. Required if the value for Blind Spot Localized (0024,0106) is YES. See Section C.8.26.4.1.3 for further explanation.
Minimum Sensitivity Value | (0024,0105) | 1 | The minimum sensitivity value generated by the equipment used for this visual field test, in dB.
Test Point Normals Data Flag | (0024,0057) | 1 | Existence of normative data base for this set of test points. Enumerated Values: YES NO
Test Point Normals Sequence | (0024,0058) | 1C | Normative data base used for this test sequence. Only a single Item shall be included in this sequence. Required if Test Point Normals Data Flag (0024,0057) is YES.
>Include Table 10-22 “Data Set Identification Macro Attributes” |
Age Corrected Sensitivity Deviation Algorithm Sequence | (0024,0065) | 1C | Software algorithm used to provide the probability that the age corrected sensitivity deviation values at each test point belong to a normal visual field. Only a single Item shall be included in this sequence. Required if Test Point Normals Data Flag (0024,0057) is YES.
>Include Table 10-19 “Algorithm Identification Macro Attributes” |
Generalized Defect Sensitivity Deviation Algorithm Sequence | (0024,0067) | 1C | Software algorithm used to provide the probability that the sensitivity deviation values at each test point belong to a normal visual field. Only a single Item shall be included in this sequence. Required if Test Point Normals Data Flag (0024,0057) is YES.
>Include Table 10-19 “Algorithm Identification Macro Attributes” |
Visual Field Test Point Sequence | (0024,0089) | 1 | Information for each test point in the visual field. One or more items shall be included in this sequence.
>Visual Field Test Point X-Coordinate | (0024,0090) | 1 | The horizontal coordinate of a single test point relative to the center of the patient fixation, in degrees, such that toward the right is positive.
>Visual Field Test Point Y-Coordinate | (0024,0091) | 1 | The vertical coordinate of a single test point relative to the center of the patient fixation, in degrees, such that up is positive.
>Stimulus Results | (0024,0093) | 1 | Whether the patient saw a stimulus presented at a luminance other than maximum, a presentation at maximum luminance, or did not see any presented stimulus. Enumerated Values: SEEN stimulus seen at a luminance value less than maximum NOT SEEN stimulus not seen SEEN AT MAX stimulus seen at the maximum luminance possible for the instrument ### Note SEEN AT MAX is a value only relevant to Screening tests.
>Sensitivity Value | (0024,0094) | 1C | If Stimulus Results (0024,0093) is SEEN then this value is the sensitivity, in dB. Required if Content Item Modifier Sequence (0040,0441) within Performed Protocol Code Sequence (0040,0260) contains an item with the value (R-408C3, SRT, "Diagnostic"). May be present otherwise. ### Note If this is not present, refer to the attribute Minimum Sensitivity Value (0024,0105).
>Retest Stimulus Seen | (0024,0095) | 3 | Whether the retested stimulus presented was seen by the patient. Enumerated Values: YES NO
>Retest Sensitivity Value | (0024,0096) | 3 | If the Retest Stimulus Seen (0024,0095) is YES, then this value is the sensitivity, in dB. ### Note If this is not present, refer to the attribute Minimum Sensitivity Value (0024,0105).
>Quantified Defect | (0024,0098) | 3 | Difference between the expected and the determined sensitivity, each in dB. ### Note This field is only useful when the sensitivity is quantified. Some examples include Test Strategy Code Sequence (0024,0015) with items providing values such as Quantity-Defects, 2LT-Dynamic, 2LT-Normal.
>Visual Field Test Point Normals Sequence | (0024,0097) | 1C | Information about normal values for each visual field test point. One or more items shall be included in this sequence. Required if Test Point Normals Data Flag (0024,0057) is YES.
>>Age Corrected Sensitivity Deviation Value | (0024,0092) | 1 | Difference between the patient's local sensitivity and the age corrected normal sensitivity, in dB.
>>Age Corrected Sensitivity Deviation Probability Value | (0024,0100) | 1 | The percentile of the age corrected sensitivity deviation within the normal population of visual field, in percent.
>> Generalized Defect Corrected Sensitivity Deviation Flag | (0024,0102) | 1 | Whether generalized defect corrected data are available for this point. Enumerated Values: YES NO
>>Generalized Defect Corrected Sensitivity Deviation Value | (0024,0103) | 1C | The age corrected sensitivity deviation after correction for the Generalized Defect, in dB. Generalized defect is proportional to the loss in sensitivity shared by all points in the visual field. Required if Generalized Defect Corrected Sensitivity Deviation Flag (0024,0102) is YES.
>>Generalized Defect Corrected Sensitivity Deviation Probability Value | (0024,0104) | 1C | The percentile of the generalized defect corrected sensitivity deviation within the normal population of visual field, in percent. Required if Generalized Defect Corrected Sensitivity Deviation Flag (0024,0102) is YES.

##### C.8.26.4.1 Visual Field Static Perimetry Test Measurement Attribute Descriptions

###### C.8.26.4.1.1 Measurement Laterality

When B (both left and right together) eyes are provided for Measurement Laterality (0024,0113) it shall mean that both eyes are open during the test (binocular). It shall not be used to provide two monocular tests (i.e., one for the left eye and one for the right). Two monocular tests require two SOP Instances and two monocular tests with one binocular test require three SOP Instances.

###### C.8.26.4.1.2 Foveal Sensitivity

For Foveal Sensitivity (0024,0087), the terminology commonly used for perimetric measurements is employed, with reference to visual thresholds designated by a decibel (dB) scale. The decibel scale for conventional perimetry is based on the maximum stimulus luminance that can be superimposed on a uniform background, and it is given a value of 0 dB of sensitivity. Sensitivity is the inverse of threshold (sensitivity = 1/threshold) and vice versa. In other disciplines, visual threshold is usually defined by the probability of seeing a difference in luminance, brightness, hue or saturation, or a difference in some other attribute exhibited by a given set of stimuli. As such, a threshold is usually described in terms of the minimum amount of luminance, contrast, hue or other attribute that can be minimally detected. However, many sources that refer to perimetry have described threshold in terms of decibel (dB) values rather than attributing the dB measures to sensitivity. It would be advisable to check each individual device to determine how dB is defined.

###### C.8.26.4.1.3 Blind Spot X and Y Coordinates

For Blind Spot X-Coordinate (0024,0107) and Blind Spot Y-Coordinate (0024,0108), the convention described below for the Cartesian coordinate system specifies that to the right is positive on the x axis and up is positive on the Y axis. Figure C.8.26.4.1-1 illustrates how visual fields are displayed in standard format with the temporal visual field from the right eye displayed to the right and the nasal visual field from the right eye to the left.

Figure C.8.26.4.1-1. Convention of coordinate system used in visual field representation.

#### C.8.26.5 Visual Field Static Perimetry Test Results Module

Table C.8.26.5-1 defines the Attributes used to interpret the test results of a patient's visual field test.

Table C.8.26.5-1. Visual Field Static Perimetry Test Results Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Visual Field Mean Sensitivity | (0024,0070) | 1C | Average sensitivity of the test points of the visual field, in dB. Required if Content Item Modifier Sequence (0040,0441) within the Performed Protocol Code Sequence (0040,0260) contains an item with the value (R-408C3, SRT, "Diagnostic"). May be present otherwise.
Visual Field Test Normals Flag | (0024,0063) | 1 | Whether normals exist for this patient's results. Enumerated Values: YES NO
Results Normals Sequence | (0024,0064) | 1C | Information that represents the statistically normal results for patients from a referenced data base. Only a single Item shall be included in this sequence. Required if Visual Field Test Normals Flag (0024,0063) is YES.
>Include Table 10-22 “Data Set Identification Macro Attributes” |
>Global Deviation from Normal | (0024,0066) | 1 | Weighted average deviation from the age corrected normal field, in dB.
>Global Deviation Probability Normals Flag | (0024,0059) | 1 | Whether normals exist for the global deviation probability. Enumerated Values: YES NO
>Global Deviation Probability Sequence | (0024,0083) | 1C | Probability value and software algorithm used to provide the normality for the global deviation. Only a single Item shall be included in this sequence. Required if Global Deviation Probability Normals Flag (0024,0059) is YES.
>>Global Deviation Probability | (0024,0071) | 1 | The percentile of the Global Deviation from Normal (0024,0066) value within the normal population, in percent.0024
>>Include Table 10-19 “Algorithm Identification Macro Attributes” |
>Localized Deviation From Normal | (0024,0068) | 1 | Weighted square root of loss variance, in dB.
>Local Deviation Probability Normals Flag | (0024,0072) | 1 | Whether normals exist for the local deviation probability. Enumerated Values: YES NO
>Localized Deviation Probability Sequence | (0024,0085) | 1C | Probability value and software algorithm used to provide the normality for the local deviation. Only a single Item shall be included in this sequence. Required if Local Deviation Probability Normals Flag (0024,0072) is YES.
>>Localized Deviation Probability | (0024,0073) | 1 | The percentile of the Localized Deviation From Normal (0024,0068) value within the normal population, in percent.
>>Include Table 10-19 “Algorithm Identification Macro Attributes” |
Short Term Fluctuation Calculated | (0024,0074) | 1 | Whether the short term fluctuation was calculated. Enumerated Values: YES NO
Short Term Fluctuation | (0024,0075) | 1C | Average deviation of sensitivity for the repeated test locations, in dB. This is used to determine the consistency of the patient's responses. Required if Short Term Fluctuation Calculated (0024,0074) is YES.
Short Term Fluctuation Probability Calculated | (0024,0076) | 1 | Whether the short term fluctuation probability was calculated. Enumerated Values: YES NO
Short Term Fluctuation Probability | (0024,0077) | 1C | The percentile of the Short Term Fluctuation (0024,0075) value within the normal population, in percent. Required if Short Term Fluctuation Probability Calculated (0024,0076) is YES.
Corrected Localized Deviation From Normal Calculated | (0024,0078) | 1 | Whether the corrected localized deviation from normal was calculated. Enumerated Values: YES NO
Corrected Localized Deviation From Normal | (0024,0079) | 1C | Weighted square root of loss variance corrected for short term fluctuation, in dB. Required if Corrected Localized Deviation From Normal Calculated (0024,0078) is YES.
Corrected Localized Deviation From Normal Probability Calculated | (0024,0080) | 1 | Whether the corrected localized deviation from Normal probability was calculated. Enumerated Values: YES NO
Corrected Localized Deviation From Normal Probability | (0024,0081) | 1C | The percentile of the Corrected Localized Deviation From Normal (0024,0079) value within the normal population, in percent. Required if Corrected Localized Deviation From Normal Probability Calculated (0024,0080) is YES.
Visual Field Global Results Index Sequence | (0024,0320) | 3 | Information about various visual field indexes related to test results. One or more Items are permitted in this sequence.
>Include Table C.8.26.3-2 “Ophthalmic Visual Field Global Index Macro Attributes” |

#### C.8.26.6 Ophthalmic Patient Clinical Information and Test Lens Parameters Module

Table C.8.26.6-1 defines the Attributes used to represent a patient's clinical parameters during an ophthalmic test.

Table C.8.26.6-1. Ophthalmic Patient Clinical and Test Lens Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Patient Clinical Information Left Eye Sequence | (0024,0114) | 1C | Information used to represent a patient's clinical parameters during an ophthalmic test. Only a single Item shall be included in this sequence. Required if Measurement Laterality (0024,0113) is L or B.
>Include Table C.8.26.6-2 “Ophthalmic Patient Clinical Information and Test Lens Parameters Macro Attributes” |
Ophthalmic Patient Clinical Information Right Eye Sequence | (0024,0115) | 1C | Information used to represent a patient's clinical parameters during an ophthalmic test. Only a single Item shall be included in this sequence. Required if Measurement Laterality (0024,0113) is R or B.
>Include Table C.8.26.6-2 “Ophthalmic Patient Clinical Information and Test Lens Parameters Macro Attributes” |

##### C.8.26.6.1 Ophthalmic Patient Clinical Information and Test Lens Parameters Macro

Table C.8.26.6-2 describes the attributes for the Ophthalmic Patient Clinical and Test Lens Parameters Macro.

Table C.8.26.6-2. Ophthalmic Patient Clinical Information and Test Lens Parameters Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Refractive Parameters Used on Patient Sequence | (0024,0112) | 2 | Refractive parameters used when performing visual field test. Zero or one Item shall be included in this sequence.
>Spherical Lens Power | (0022,0007) | 1 | Sphere value in diopters.
>Cylinder Lens Power | (0022,0008) | 1 | Cylinder value in diopters.
>Cylinder Axis | (0022,0009) | 1 | Axis value in degrees.
Pupil Size | (0046,0044) | 2 | The horizontal diameter measurement of the pupil, in mm.
Pupil Dilated | (0022,000D) | 2 | The patient's pupils were pharmacologically dilated for this acquisition. Enumerated Values: YES NO If this tag is empty, no information is available.
Intra Ocular Pressure | (0022,000B) | 3 | Value of intraocular pressure in mmHg.
Visual Acuity Measurement Sequence | (0024,0110) | 3 | Measurements of a patient's visual acuity. Only a single Item is permitted in this sequence.
>Include Table C.8.25.12-2 “Visual Acuity Measurements Macro Attributes” |

### C.8.27 Intravascular Optical Coherence Tomography Modules

#### C.8.27.1 Intravascular OCT Series Module

Table C.8.27.1-1 specifies the Attributes that identify and describe general information about the Intravascular Optical Coherence Tomography Series.

Table C.8.27.1-1. Intravascular OCT Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: IVOCT See Section C.7.3.1.1.1 for further explanation.
Series Number | (0020,0011) | 1 | A number that identifies this Series.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Referenced SOP Class UID | (0008,1150) | 1 | Uniquely identifies the referenced SOP Class.
>Referenced SOP Instance UID | (0008,1155) | 1 | Uniquely identifies the referenced SOP Instance.
Presentation Intent Type | (0008,0068) | 1 | Identifies the intent of the images that are contained within this Series. Enumerated Values: FOR PRESENTATION FOR PROCESSING

##### C.8.27.1.1 Intravascular OCT Series Attribute Descriptions

###### C.8.27.1.1.1 Presentation Intent Type

Presentation Intent Type (0008,0068) identifies the intent for the purposes of display or other presentation of all Images within this Series.

### Note

1. Since this is a Series level attribute, all Images within a Series have the same value for this Attribute.

2. The intent of this restriction is to ensure that FOR PRESENTATION and FOR PROCESSING images are placed in separate Series, so that no confusion can arise as to which images are suitable for diagnostic reading as determined by local policy.

A Series of Images intended for viewing by an observer shall have an Enumerated Value of FOR PRESENTATION. The value shall not be set to FOR PRESENTATION unless Z Offset correction, refractive index correction and polar to rectangular conversion have been applied

Images or individual frames of a FOR PRESENTATION image shall reference their associated source FOR PROCESSING frames, if any exist, using the Derivation Image Functional Group Macro, with the Derivation Code (113093, DCM, "Polar to Rectangular Scan Conversion") and the Purpose of Reference Code (121358, DCM, "For Processing Image").

### Note

1. FOR PRESENTATION images are still be of Image Type (0008,0008) and Frame Type (0008,9007) ORIGINAL rather than DERIVED despite having undergone processing, such as corrections for Z Offset, Refractive index and Polar to Rectangular conversion. In this case a DERIVED image would have undergone yet further processing to make it substantially different from the original. See Figure C.8.27-1. The Derivation Image Functional Group Macro may be used even if Image Type (0008,0008) and Frame Type (0008,9007) is ORIGINAL.

2. FOR PRESENTATION images may still be subjected to processing or further processing, if appropriate, depending on the application.

3. FOR PRESENTATION images are intended for display on a device, without (further) processing, since that device may not be capable of image processing. The quality of the displayed image or its suitability for any purpose is beyond the scope of the DICOM Standard.

4. If all of the frames of a FOR PRESENTATION image are created by processing all of the frames of a FOR PROCESSING image, then a reference to the FOR PROCESSING SOP Instance only, without reference to specific frame numbers, in the Shared Functional Group Sequence avoids the need for a frame-by-frame reference in each Per-Frame Functional Group, though there is no requirement that the order of the frames or the number of frames in the FOR PROCESSING and FOR PRESENTATION instances correspond.

FOR PROCESSING images may have Z Offset correction applied to the A-line data and/or Refractive Index applied to A-line Pixel Spacing (0052,0014). However, due to irreversible loss of information, images that have had Polar to Rectangular scan conversion applied shall not be stored as FOR PROCESSING images.

Figure C.8.27-1. Explanation of Presentation Intent Type

#### C.8.27.2 Intravascular OCT Image Module

Table C.8.27.2-1 specifies the Attributes that describe an Image produced by Intravascular OCT imaging modalities.

Table C.8.27.2-1. Intravascular OCT Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.27.2.1 for specialization.
Volumetric Properties | (0008,9206) | 1 | Indication if geometric manipulations are possible with frames in the SOP Instance. See Section C.8.27.2.2.
Pixel Presentation | (0008,9205) | 1 | Indication of the presence or absence of color information that may be used during rendering. See Section C.8.27.2.3 for a description and Enumerated Values.
Samples Per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. Enumerated Values: 1
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data started. ### Note The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800).
Acquisition Duration | (0018,9073) | 1C | The scan time in seconds used to create all frames of an Intravascular Optical Coherence Tomography image. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.
Acquisition Number | (0020,0012) | 1 | A number identifying the single continuous gathering of data over a period of time that resulted in this image.
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME2
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. Enumerated Values: 0
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. See Section C.8.27.2.4 for specialization.
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. See Section C.8.27.2.4 for specialization.
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. High Bit (0028,0102) shall be one less than Bits Stored (0028,0101).
Presentation LUT Shape | (2050,0020) | 1C | Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY output is in P-Values. Required if Presentation Intent Type (0008,0068) equals FOR PRESENTATION.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). Required if Lossy Image Compression (0028,2110) is "01". ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111).
Burned In Annotation | (0028,0301) | 1 | Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 1 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: NO
Referenced Instance Sequence | (0008,114A) | 3 | A sequence that provides reference to a set of non-image SOP Class/Instance pairs significantly related to this Image, including waveforms that may or may not be temporally synchronized with this image. One or more Items are permitted in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Code describing the purpose of the reference to the SOP Instances. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID is CID 7004 “Waveform Purposes of Reference” for referenced waveforms.
Image Comments | (0020,4000) | 3 | User-defined comments about the image.
Recommended Display Frame Rate | (0008,2144) | 3 | Recommended rate at which the frames of an Intravascular OCT image should be displayed in frames/second.
Interpolation Type | (0052,0039) | 1C | The type of interpolation used for the Polar to Cartesian scan-conversion. Defined Terms: REPLICATE BILINEAR CUBIC Required if Presentation Intent Type (0008,0068) equals FOR PRESENTATION.
Referenced Color Palette Instance UID | (0028,0304) | 1C | The identifier of a color palette (i.e., an instance of the Color Palette Storage SOP Class "1.2.840.10008.5.1.4.39.1") that may be used during rendering. See PS3.4 Color Palette Storage Service Class and PS3.6 Well-Known Color Palettes. Required if Pixel Presentation (0008,9205) is COLOR_REF.

##### C.8.27.2.1 Image Type and Frame Type

In addition to the requirements specified in Section C.8.16.1 Image Type, the following additional requirements and Defined Terms are specified.

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or Defined Terms.

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or Defined Terms.

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.3.

Table C.8.27.2-2 specifies the Defined Terms for IVOCT for Value 3 for Image Type (0008,0008) and Frame Type (0008,9007).

Table C.8.27.2-2. IVOCT Image Type and Frame Type Value 3

Defined Term Name | Defined Term Description
--- | ---
AXIAL | An image that has an orientation that is perpendicular to the long axis of the vessel. (i.e., cross-sectional).
LONGITUDINAL | An image that has an orientation that is parallel to the long axis of the vessel.

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.4. No additional requirements or Defined Terms.

##### C.8.27.2.2 Volumetric Properties

The value of Volumetric Properties attribute (0008,9206) allows applications doing geometric manipulations to determine if the image is an appropriate candidate for an operation without having to know all the details of the generating application.

Table C.8.27.2-3 specifies the Enumerated Values for Volumetric Properties (0008,9206).

Table C.8.27.2-3. Volumetric Properties Attribute Values

Enumerated Value Name | Enumerated Value Description
--- | ---
DISTORTED | Frames do not represent the true geometry of the vessel.

##### C.8.27.2.3 Pixel Presentation

Pixel Presentation (0008,9205) is used to indicate whether a color tint is intended to be applied to the IVOCT image. See Table C.8.27.2-4.

Table C.8.27.2-4. Pixel Presentation Attribute Values

Enumerated Value Name | Enumerated Value Description
--- | ---
COLOR | Image is intended to be displayed in color using Supplemental Palette Color LUTs, but can be displayed in grayscale if current display does not support color or with a user selected LUT. See Section C.8.16.2.1.1.1.
COLOR_REF | Image is intended to be displayed in color using an externally defined Palette Color LUTs, but can be displayed in grayscale if current display does not support color, or with a user selected LUT. I.e., the encoded pixel values are still continuous grayscale values (and not arbitrarily order indices into a lookup table).
MONOCHROME | Image is intended to be displayed in grayscale only.

##### C.8.27.2.4 Bits Allocated, Bits Stored and Samples Per Pixel

For IVOCT images, Bits Allocated (0028,0100), Bits Stored (0028,0101) Samples Per Pixel (0028,0002) are specified to use the following values for Presentation Intent Type (0008,0068) attribute:

Table C.8.27.2-5. Bits Allocated/Stored

Presentation Intent Type | Bits Allocated / Bits Stored | Samples Per Pixel
--- | --- | ---
FOR PRESENTATION | 8/8, 16/12 or 16/16 | 1
FOR PROCESSING | 8/8, 16/12 or 16/16 | 1

#### C.8.27.3 Intravascular OCT Acquisition Parameters Module

Table C.8.27.3-1 describes the parameters used to acquire an Intravascular Optical Coherence Tomography image.

Table C.8.27.3-1. Intravascular OCT Acquisition Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
OCT Focal Distance | (0052,0002) | 2 | Distance from focal point to center of catheter, in mm (measured in air).
Beam Spot Size | (0052,0003) | 2 | The full width at half maximum (FWHM) of the point spread function (PSF) or line spread function (LSF), in µm (measured in air). Also known as Transverse Resolution.
Effective Refractive Index | (0052,0004) | 2C | Index of refraction of the tissue and flush medias used during the Intravascular OCT acquisition. Required if Presentation Intent Type (0008,0068) is FOR PROCESSING. May be present otherwise.
OCT Acquisition Domain | (0052,0006) | 1 | The type of OCT acquisition domain. Defined Terms: TIME FREQUENCY SPECTRAL
OCT Optical Center Wavelength | (0052,0007) | 2 | Center optical wavelength of the OCT light source, in µm.
Axial Resolution | (0052,0008) | 2 | The full width at half maximum (FWHM) of the axial plane response function, in µm (measured in air)
Ranging Depth | (0052,0009) | 1 | Maximum detectable sample-to-reference path displacement, in mm (measured in air). This is the radius of the FOR PRESENTATION image in air. ### Note Ranging Depth is distinct from Penetration Depth, which is the depth to which one can obtain an OCT signal in tissue.
A-line Rate | (0052,0011) | 1 | The number of IVOCT A-lines acquired per second in Hz.
A-lines Per Frame | (0052,0012) | 1 | Number of A-lines acquired in an IVOCT frame, including unused (padded) A-lines. ### Note Will be the same as Rows (0028,0010) for a FOR PROCESSING image.

#### C.8.27.4 Intravascular OCT Processing Parameters Module

Table C.8.27.4-1 describes the parameters used for processing an Intravascular Optical Coherence Tomography polar data image.

Table C.8.27.4-1. Intravascular OCT Processing Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
OCT Z Offset Applied | (0052,0026) | 1 | Indicates whether or not Z offset correction was applied to the OCT image frames. Enumerated Values: YES NO
Refractive Index Applied | (0052,003A) | 1 | Indicates whether or not Refractive Index correction was applied. Enumerated Values: YES NO See Section C.8.27.4.1 for further explanation.
A-line Pixel Spacing | (0052,0014) | 1 | Spacing of pixels in the A-line (X-axis), in mm.
Pixel Intensity Relationship | (0028,1040) | 1 | The relationship between the pixel sample values and the IVOCT A-line intensity. See Section C.8.27.4.2.
First A-line Location | (0052,0034) | 1 | Orientation in degrees at which the 1st A-line in the frame should be displayed. Value shall be between 0 and 360, with zero representing vertical.

##### C.8.27.4.1 Refractive Index Applied

For Refractive Index Applied (0052,003A) a value of YES indicates that Effective Refractive Index (0052,0004) correction has been applied to the reported A-line Pixel Spacing (0052,0014) attribute. A value of NO indicates that Effective Refractive Index (0052,0004) correction has not been applied (i.e., A-line Pixel Spacing corresponds to the pixel spacing in air).

###### C.8.27.4.2 Pixel Intensity Relationship

Pixel Intensity Relationship (0028,1040) shall identify the relationship of the pixel values to the IVOCT A-line intensity.

Defined Terms:

LIN

  Approximately proportional to A-line intensity.

LOG

  Non-linear "Log Function"; A Pixel Intensity Relationship LUT shall be included with the image to allow it to be scaled back to its proportional A-line intensity value.

#### C.8.27.5 Intravascular Image Acquisition Parameters Module

Table C.8.27.5-1 describes the parameters and characteristics of an intravascular image acquisition. These parameters are common to both IVUS and IVOCT.

Table C.8.27.5-1. Intravascular Image Acquisition Parameters Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
IVUS Acquisition | (0018,3100) | 1 | Type of Intravascular Image Acquisition. Enumerated Values: MOTORIZED MANUAL SELECTIVE MEASURED See Section C.8.27.5.1.
IVUS Pullback Rate | (0018,3101) | 1C | Intravascular imaging catheter pullback rate. Specified in units of mm/sec. Required if IVUS Acquisition (0018,3100) value is MOTORIZED. See Section C.8.27.5.2.
IVUS Pullback Start Frame Number | (0018,3103) | 1C | Frame number at which the motorized portion of the acquisition begins. Required if IVUS Acquisition (0018,3100) value is MOTORIZED. See Section C.8.27.5.1.
IVUS Pullback Stop Frame Number | (0018,3104) | 1C | Frame number at which the motorized portion of the acquisition is complete. Required if IVUS Acquisition (0018,3100) value is MOTORIZED. See Section C.8.27.5.1.
Catheter Direction of Rotation | (0052,0031) | 1C | Direction of rotation of the Intravascular rotating catheter during acquisition, from the perspective of the motor, proximal to distal. Enumerated Values: CW clockwise CC counter-clockwise Required if rotational catheter is used.
Catheter Rotational Rate | (0052,0013) | 1C | Rate of rotation of the Intravascular rotating catheter during acquisition, in Hz. Required if rotational catheter is used.
Mode of Percutaneous Access Sequence | (0052,0016) | 2 | Mode of access of the Intravascular Imaging Catheter. Zero or one Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 3746 “Percutaneous Entry Site”.

##### C.8.27.5.1 IVUS Acquisition

The attribute IVUS Acquisition (0018,3100) denotes the method used to acquire the Intravascular Images.

MOTORIZED: The Intravascular imaging catheter is positioned in the blood vessel proximal or distal to the anatomical structures to be examined. The catheter is attached to a motorized mechanism capable of either pushing forward or pulling back the catheter through the vessel at a constant velocity, as specified by the IVUS Pullback Rate (0018,3101). The motorized acquisition takes place during the time between acquisition of the IVUS Pullback Start Frame Number (0018,3103), and acquisition of the IVUS Pullback Stop Frame Number (0018,3104).

MANUAL: The Intravascular imaging catheter is positioned in the blood vessel proximal or distal to the anatomical structures to be examined. The catheter is then manually pulled back or pushed forward through the vessel segment of interest.

SELECTIVE: The Intravascular imaging catheter is positioned in the blood vessel. The catheter is then manually pushed forward and/or pulled back to examine the anatomical structures in the vessel.

MEASURED: The Intravascular imaging catheter is positioned in the blood vessel near the anatomical structures to be examined. The catheter is then pulled back or pushed forward through the vessel segment of interest. The longitudinal movement between each acquired frame is measured and recorded. See Section C.8.27.6.2 for more information.

##### C.8.27.5.2 IVUS Pullback Rate

The attribute IVUS Pullback Rate (0018,3101) specifies the constant velocity of longitudinal movement of the Intravascular imaging catheter. Positive values indicate movement from Distal to Proximal (pulling back). Negative values indicate movement from Proximal to Distal (pushing forward).

#### C.8.27.6 Intravascular OCT Functional Group Macros

The following sections contain Functional Group Macros specific to the Intravascular OCT IOD.

##### C.8.27.6.1 Intravascular OCT Frame Type Macro

Table C.8.27.6.1-1 specifies the attributes of the Intravascular OCT Frame Type Functional Group.

Table C.8.27.6.1-1. Intravascular OCT Frame Type Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Intravascular OCT Frame Type Sequence | (0052,0025) | 1 | Identifies characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type | (0008,9007) | 1 | Type of Frame. A multi-valued attribute analogous to Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of Image Type (0008,0008), except that the value MIXED is not allowed. See Section C.8.27.2.1.

##### C.8.27.6.2 Intravascular Frame Content Macro

Table C.8.27.6.2-1 specifies the attributes of the Intravascular Frame Content Functional Group.

Table C.8.27.6.2-1. Intravascular Frame Content Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Intravascular Frame Content Sequence | (0052,0027) | 1 | A sequence that describes a general description of this image or frame. Only a single Item shall be included in this sequence.
>Intravascular Longitudinal Distance | (0052,0028) | 1C | Longitudinal distance in millimeters between this frame and the previous acquired frame. Positive values indicate movement is from Distal to Proximal (pull back). Negative values indicate movement is from Proximal to Distal (push forward). Required if Intravascular Acquisition (0018,3100) equals MEASURED.
>Seam Line Location | (0052,0033) | 2C | Clockwise rotational orientation (in degrees) at which the seam line in the frame is displayed, relative to vertical (zero degrees). Required if Presentation Intent Type (0008,0068) equals FOR PRESENTATION.

##### C.8.27.6.3 Intravascular OCT Frame Content Macro

Table C.8.27.6.3-1 specifies the attributes of the Intravascular OCT Frame Content Functional Group.

Table C.8.27.6.3-1. Intravascular OCT Frame Content Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Intravascular OCT Frame Content Sequence | (0052,0029) | 1 | A sequence that describes a general description of this image or frame. Only a single Item shall be included in this sequence.
>OCT Z Offset Correction | (0052,0030) | 1 | The amount to shift the frame along the axial direction, in pixels, to correct for interferometer path-length mismatch. See Section C.8.27.6.3.1 for further explanation.
>Seam Line Index | (0052,0036) | 1 | The A-line number (zero index) that coincides with the seam line as indicated with the First A-line Location (0052,0034) attribute.
>Number of Padded A-lines | (0052,0038) | 1C | The number of padded A-lines contained in the FOR PROCESSING image frame. Required if the FOR PROCESSING image contains padded A-lines. See Section C.8.27.6.3.2 for further explanation.

###### C.8.27.6.3.1 OCT Z Offset Correction

OCT Z Offset Correction (0052,0030) specifies the number of pixels to shift the A-lines of the frame to correct for the path length difference between the OCT Sample arm and Reference arm (in air). A positive value of Z Offset correction means pixels are shifted further away from the catheter optics. A negative value of Z Offset correction means pixels are shifted closer to the catheter optics. See Figure C.8.27-2

Figure C.8.27-2. OCT Z Offset Correction Example

###### C.8.27.6.3.2 A-line Padding

Padded A-lines shall not be used in FOR PRESENTATION frames. Padded A-lines shall only be encoded in the high order rows of the FOR PROCESSING frame and shall be contiguous. Padded A-lines may contain arbitrary pixel values.

### C.8.28 Ophthalmic Thickness Map Modules

#### C.8.28.1 Ophthalmic Thickness Map Series Module

Table C.8.28.1-1 specifies the Attributes that identify and describe general information about the Ophthalmic Thickness Map Series.

Table C.8.28.1-1. Ophthalmic Thickness Map Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that created the maps in this Series. Enumerated Values: OPM See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.28.2 Ophthalmic Thickness Map Module

Table C.8.28.2-1 specifies the Attributes that describe an Image produced by ophthalmic thickness mapping devices.

Table C.8.28.2-1. Ophthalmic Thickness Map Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Mapping Device Type | (0022,1415) | 1 | Describes the type of ophthalmic mapping acquisition device. See Section C.8.28.2.1.3 for further explanation. Defined Terms OCT Optical coherence tomography POLARIMETRY Scanning laser polarimetry SLO_TOMO Scanning Laser Ophthalmoscopy Tomography
Acquisition Method Code Sequence | (0022,1420) | 1 | The acquisition method used for obtaining ophthalmic thickness mapping. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4261 “Ophthalmic Mapping Acquisition Method”
Acquisition Method Algorithm Sequence | (0022,1423) | 1C | Software algorithm used to provide acquisition method. Required if Acquisition Method Code Sequence (0022,1420) contains an item with the value of (111923, DCM, "Corneal birefringence compensation") May be present otherwise. Only a single Item shall be included in this sequence.
>Include Table 10-19 “Algorithm Identification Macro Attributes” |
Instance Number | (0020,0013) | 1 | A number that identifies this instance.
Content Date | (0008,0023) | 1 | The date the data creation was started.
Content Time | (0008,0033) | 1 | The time the data creation was started.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started. ### Note The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.28.2.1.1 for specialization.
Samples Per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.7.6.3.1.1 for further explanation. Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Specified the intended interpretation of the pixel data. See Section C.7.6.3.1.2 for further explanation. Enumerated Values: MONOCHROME2
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. Enumerated Values: 0000H unsigned integer
Pixel Spacing | (0028,0030) | 1 | Physical distance in the patient between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. ### Note Since a patient's retina is curved, there can be a small error in using Pixel Spacing (0028,0030) for distance measurements in the periphery of the image. See Section 10.7.1.3 for further explanation.
Pixel Aspect Ratio | (0028,0034) | 1 | Ratio of the vertical size and horizontal size of the pixels in the image specified by a pair of integer values where the first value is the vertical pixel size, and the second value is the horizontal pixel size.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See PS3.5 for further explanation. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Enumerated Values: 8 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. See PS3.5 for further explanation. Enumerated Values: 7 if Bits Stored (0028,0101) = 8 15 if Bits Stored (0028,0101) = 16
Pixel Presentation | (0008,9205) | 1 | The source of the color information for use during rendering. Enumerated Values: COLOR Use Supplemental Palette Color LUT Module Attributes COLOR_REF Use Referenced Color Palette Instance UID (0028,0304)
Referenced Color Palette Instance UID | (0028,0304) | 1C | The identifier of the color palette (i.e., an instance of the Color Palette Storage SOP Class "1.2.840.10008.5.1.4.39.1") for use during rendering. Required if Pixel Presentation (0008,9205) is COLOR_REF.
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Burned In Annotation | (0028,0301) | 1 | Indicates that the image does not contain burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 1 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: NO
Image Laterality | (0020,0062) | 1 | Laterality of object imaged (as described in Anatomic Region Sequence (0008,2218)) examined. Enumerated Values: R right eye L left eye ### Note This Attribute is mandatory, in order to ensure that images may be positioned correctly relative to one another for display. Shall be consistent with any laterality information contained in Primary Anatomic Structure Modifier Sequence (0008,2230), if present. ### Note Laterality (0020,0060) is a Series level Attribute and must be the same for all Images in the Series, hence it must be absent.
Ophthalmic Thickness Map Type Code Sequence | (0022,1436) | 1 | The type of ophthalmic thickness map encoded in this SOP Instance. It specifies the meaning of the pixel values. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4263 “Ophthalmic Thickness Map Value Type”
Include Table C.7.6.16-12 “Real World Value Mapping Macro Attributes” if Ophthalmic Thickness Map Type Code Sequence (0022,1436) contains an item with the value (111930, DCM, "Absolute ophthalmic thickness") or (111932, DCM, "Thickness deviation from normative data"). May be present otherwise. | Defined CID for Measurement Units Code Sequence is 4260
Pixel Value Mapping to Coded Concept Sequence | (0022,1450) | 1C | Provides a pixel value and the mapping of that pixel value to an associated Coded Concept. Required if Ophthalmic Thickness Map Type Code Sequence (0022,1436) contains an item with the value (111931, DCM, "Thickness deviation category from normative data"). May be present otherwise. One or more Items shall be present.
>Mapped Pixel Value | (0022,1452) | 1 | Pixel value to be mapped.
>Pixel Value Mapping Code Sequence | (0040,9098) | 1 | The mapping from Mapped Pixel Value (0022,1452) to an associated Coded Concept. Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4265 “Ophthalmic Thickness Deviation Categories”.
>Pixel Value Mapping Explanation | (0022,1454) | 3 | Free form text explanation of the Coded Concept.
Ophthalmic Thickness Mapping Normals Sequence | (0022,1443) | 1C | Identifies the data set used for mapping values from a normative data base. Required if Ophthalmic Thickness Map Type Code Sequence (0022,1436) contains an item with the value or (111931, DCM, "Thickness deviation category from normative data") or (111932, DCM, "Thickness deviation from normative data"). May be present otherwise. Only a single Item shall be included in this sequence.
>Include Table 10-22 “Data Set Identification Macro Attributes” |
Relevant OPT Attributes Sequence | (0022,1472) | 1C | Attributes from the OPT image that provide critical context for the interpretation of this ophthalmic map SOP Instance. Required if Ophthalmic Mapping Device Type (0022,1415) is OCT. Only a single Item shall be included in this sequence
>Depth Spatial Resolution | (0022,0035) | 1 | The inherent limiting resolution in microns for depth of the acquisition equipment for high contrast objects for the data gathering and reconstruction technique chosen. If variable, the value at the center of the scanning volume.
>Maximum Depth Distortion | (0022,0036) | 1 | Maximum distortion in depth direction in % of Depth Spatial Resolution.
Source Image Sequence | (0008,2112) | 1C | The Image SOP Class/Instance pair of the Image that was used to generate this Image. Required if Ophthalmic Mapping Device Type (0022,1415) is OCT. May be present otherwise. Only a single Item shall be included in this sequence
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made, (i.e., the role the source image or frame(s) played in the generation of this image). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 7202 “Source Image Purposes of Reference”.
Referenced Instance Sequence | (0008,114A) | 1C | A sequence that provides reference to a set of SOP Class/Instance pairs identifying images or other composite SOP Instances to plan the acquisition or significant related information. Required if Ophthalmic Photography Reference Image available. May be present otherwise. See Section C.7.6.16.2.5.1 for further explanation. Zero or more Items may be included in this Sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Code describing the purpose of the reference to the Instance(s). Only a single Item shall be included in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4264 “Ophthalmic Map Purposes of Reference”.
Registration to Localizer Sequence | (0022,1465) | 3 | Registration of current instance to a localizer SOP Instance referenced in Attribute Referenced Instance Sequence (0008,114A). See Section C.8.28.2.1.2 for an example.
>Registered Localizer Units | (0022,1466) | 1 | Units of measure for the axes of the registered localizer image. Enumerated Values: PIXEL See Bounding Box Annotation Units (0070,0003) for definition.
>Registered Localizer Top Left Hand Corner | (0022,1467) | 1 | Location of the Top Left Hand Corner (TLHC) of the registered localizer in Registered Localizer Units (0022,1466), given as column\row. Column is the horizontal offset and row is the vertical offset.
>Registered Localizer Bottom Right Hand Corner | (0022,1468) | 1 | Location of the Bottom Right Hand Corner (BRHC) of the registered localizer in which Registered Localizer Units (0022,1466), given as column\row. Column is the horizontal offset and row is the vertical offset.
Include Table 10-5 “General Anatomy Mandatory Macro Attributes” | The concept code for Anatomic Region Sequence (0008,2218) shall be (T-AA000, SRT, "Eye"), and Defined CID 244 “Laterality” shall be used for Anatomic Region Modifier Sequence (0008,2220). Defined CID 4266 “Ophthalmic Anatomic Structure Reference Point” shall be used for Primary Anatomic Structure Sequence (0008,2228). Only a single Item shall be included in this sequence. ### Note Although Primary Anatomic Structure Sequence (0008,2228) is Type 3, it is important to convey this information if able to be determined.
Relative Image Position Code Sequence | (0022,001D) | 3 | The position of this image on the retina (as defined by a specified nomenclature; the nomenclature is implicit in the code used). Only a single Item is permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes”. | Baseline CID 4207 “Ophthalmic Image Position”.
Anatomic Structure Reference Point | (0022,1463) | 1C | Location of a point in the image identified by an anatomic structure. This is used in ophthalmology for a landmark within a patient's eye. Given as column\row. Column is the horizontal offset and row is the vertical offset. Image relative position specified with sub-pixel resolution such that the origin at the Top Left Hand Corner (TLHC) of the TLHC pixel is 0.0\0.0, the Bottom Right Hand Corner (BRHC) of the TLHC pixel is 1.0\1.0, and the BRHC of the BRHC pixel is Columns\Rows (see Figure C.10.5-1). The values must be within the range 0\0 to Columns\Rows. Required if Primary Anatomic Structure Sequence (0008,2228) contains an item with the value (T-AA621, SRT "Fovea centralis") or (T-AA630, SRT, "Optic nerve head") or (M-01000, SRT, "Lesion") or (111934, DCM, "Disc-Fovea"). May be present otherwise.
Retinal Thickness Definition Code Sequence | (0022,1445) | 1C | The definition of the retinal thickness for this image. Required if Attribute Image Type (0008,0008) value 3 is RETINAL_THICK. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4262 “Retinal Thickness Definition”

##### C.8.28.2.1 Ophthalmic Thickness Map Module Attribute Descriptions

###### C.8.28.2.1.1 Image Type

For Ophthalmic Thickness Maps, Image Type (0008,0008) is specified to be Type 1 and uses one of the following Defined Terms for Value 3:

Defined Terms:

ONH

  identifies a topographic map of an optic nerve head

RETINAL_THICK

  identifies a Thickness Map for retinal layers or combination of several sub-layers

### Note

1. The images created based upon the source data of the patient examination would be ORIGINAL\PRIMARY.

2. If the value is specified as "RETINAL_THICK", the definition of the retinal thickness is in Retinal Thickness Definition Code Sequence (0022,1445).

###### C.8.28.2.1.2 Referenced Instance Sequence

Equipment generating an ophthalmic map (OPM) image, may also obtain an accompanying "reference/localizer" image. This "reference/localizer" image serves the purpose of orienting and registering the OPM image to the actual retinal location. For example, a fundus photo may be obtained with ophthalmic tomography (OPT). When the retinal thickness map is generated based on OPT data, the OPM is registered with pixel precision to the fundus photo. This "reference/localizer" image is referenced in the OPM SOP Instance using the attribute Referenced Instance Sequence (0008,114A).

An example of a "reference/localizer" image and its relationship to an OPM image is shown in Figure C.8.28.2.1-1. Legend: ( A ) a fundus photo is taken as the "reference/localizer" image. The green box indicates the area the OPT scans are obtained. ( B ) The retinal thickness map (OPM object) is overlaid on the "reference/localizer" fundus photo to show the correspondence. These examples could be referenced from different types of SOP Classes, such as Color Softcopy Presentation State Storage (referencing the OP SOP Instance of a fundus photo), True Color Secondary Capture Image Storage, Encapsulated PDF, etc. The Purpose of Reference Code Sequence (0040,A170) code is set to (DCM, 121311, Localizer) for example A. Registration to Localizer Sequence (0022,1465) would be used for example B.

Figure C.8.28.2.1-1. Reference/Localizer Image Related to OPM Image

###### C.8.28.2.1.3 Ophthalmic Mapping Device Type

For Ophthalmic Mapping Device Type (0022,1415), Scanning Laser Ophthalmoscopy Tomography (SLO_TOMO) produces a topographical representation of the optic nerve head (ONH) rather than a thickness depiction. However, the topographical depiction can be considered as "thickness" measurements of multiple points of the ONH surface relative to an assigned datum plane. For this reason, the topographical image is included in the ophthalmic thickness map module.

Figure C.8.28.2.1-2. Optic Nerve Head Thickness Example

For Ophthalmic Mapping Device Type (0022,1415), Polarimetric Tomography (POLARIMETRY) produces a thickness depiction based on birefringent phase shifts. This is a thickness measure but does not use typical international system of units such as micrometer, etc. Due to this, the unit of measurement is defined by the implementation, such as 'p-um'.

Figure C.8.28.2.1-3. Polarimetry Optic Nerve Head Thickness Example

#### C.8.28.3 Ophthalmic Thickness Map Quality Rating Module

Table C.8.28.3-1 specifies the Attributes that describe the quality rating for the ophthalmic mapping.

Table C.8.28.3-1. Ophthalmic Thickness Map Quality Rating Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Thickness Map Quality Rating Sequence | (0022,1470) | 1 | Type of metric and metric value used to evaluate the quality of the ophthalmic mapping for grading and diagnostic purposes for this SOP Instance. Only a single Item shall be included in this sequence.
>Include Table 10-26 “Numeric Value Macro Attributes” | Defined CID 4243 “Ophthalmic Axial Length Quality Metric Type” shall be used for Concept Name Code Sequence (0040,A043)
>Ophthalmic Thickness Map Quality Threshold Sequence | (0022,1458) | 1 | Quality threshold value and software algorithm used to provide the ophthalmic thickness map quality rating for this SOP Instance. Only a single Item shall be included in this sequence.
>>Ophthalmic Thickness Map Threshold Quality Rating | (0022,1460) | 1 | Quality rating threshold value for acceptable ophthalmic map. ### Note The units of this Attribute is the same as defined in Measurement Unit Code Sequence (0040,08EA) of the Ophthalmic Thickness Map Quality Rating Sequence (0022,1470). The threshold value is not the same as the attribute Numeric Value (0049,A30A) of the Ophthalmic Thickness Map Quality Rating Sequence (0022,1470). Therefore, it conveys the least stringent value that is acceptable, not the actual rating for this SOP Instance.
>>Include Table 10-19 “Algorithm Identification Macro Attributes” |

### C.8.29 Optical Surface Scanner Modules

This Section describes Optical Surface Scanner Modules. These Modules contain Attributes that are specific to Optical Surface Scanner scans.

#### C.8.29.1 Optical Surface Scanner Series Module

Table C.8.29-1 contains IOD Attributes that describe an optical surface scan series performed on the patient.

Table C.8.29-1. Optical Surface Scanner Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: OSS See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related. Only a single Item shall be included in this sequence. Required if a Performed Procedure Step SOP Class was involved in the creation of this Series.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Referenced Surface Data Sequence | (0080,0013) | 2 | Lists the predecessor surfaces and/or point clouds instances. Zero or more Items shall be included in this sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |

#### C.8.29.2 Scan Procedure Module

Table C.8.29-2 specifies the Attributes of the Scan Procedure Module.

Table C.8.29-2. Scan Procedure Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Surface Scan Acquisition Type Code Sequence | (0080,0001) | 1 | Specify the type of acquisition method. For evaluation of the characteristics or quality of the data. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 8201 “Surface Scan Acquisition Types”.
Surface Scan Mode Code Sequence | (0080,0002) | 2 | Used scan mode. Zero or more Items shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 8202 “Surface Scan Mode Types”.
Registration Method Code Sequence | (0080,0003) | 1C | Method for registering multiple shots. Required if the IOD stores data that has been derived from multiple shots. Only a single Item shall be included in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Baseline CID 8203 “Surface Scan Registration Method Types”.
Instance Number | (0020,0013) | 1 | A number that identifies this shot. Shall start at 1 and monotonically increase by 1 within a single acquisition.
Acquisition Number | (0020,0012) | 1 | A number identifying the single continuous gathering of data over a period of time that resulted in this instance.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this instance started.
Shot Duration Time | (0080,0004) | 1 | The time in seconds from the start of this shot until the end of this shot.
Shot Offset Time | (0080,0005) | 3 | The time in seconds from the Acquisition DateTime to the start of this shot.

##### C.8.29.2.1 Scan Procedure Attribute Descriptions

###### C.8.29.2.1.1 Shot Duration Time and Shot Offset Time

Figure C.8.29.2-1 depicts the usages of some of the attributes of the Scan Procedure Module.

The Shot Offset Time is the time required for the detection of focus points and exposure time settings.

The Shot Duration Time is the time required to acquire a surface from the scanned object.

Figure C.8.29.2-1. Timing Attributes Illustration

### C.8.30 Corneal Topography Map Modules

#### C.8.30.1 Corneal Topography Map Series Module

Table C.8.30.1-1 specifies the Attributes that identify and describe general information about the Corneal Topography Map Series.

Table C.8.30.1-1. Corneal Topography Map Series Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Modality | (0008,0060) | 1 | Type of equipment that created the maps in this Series. Enumerated Values: OPM See Section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence | (0008,1111) | 1C | Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related (e.g., a Modality or General-Purpose Performed Procedure Step SOP Instance). Only a single Item shall be permitted in this sequence. Required if the Modality Performed Procedure Step SOP Class, or General Purpose Performed Procedure Step SOP Class is supported.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Body Part Examined | (0018,0015) | 1 | Text description of the part of the body examined. Enumerated Values: EYE ### Note Some IODs support the Anatomic Region Sequence (0008,2218), which can provide a more comprehensive mechanism for specifying the body part being examined.

#### C.8.30.2 Corneal Topography Map Image Module

Table C.8.30.2-1 specifies the Attributes that describe an Image produced by corneal topography mapping devices.

Table C.8.30.2-1. Corneal Topography Map Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Instance Number | (0020,0013) | 1 | A number that identifies this instance.
Content Date | (0008,0023) | 1 | The date the data creation was started.
Content Time | (0008,0033) | 1 | The time the data creation was started.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started. ### Note The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Image Type | (0008,0008) | 1 | Image identification characteristics. See Section C.8.30.2.1.1 for specialization.
Samples Per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. See Section C.7.6.3.1.1 for further explanation. Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Specified the intended interpretation of the pixel data. See Section C.7.6.3.1.2 for further explanation. Enumerated Values: PALETTE COLOR
Pixel Representation | (0028,0103) | 1 | Data representation of pixel samples. Enumerated Values: 0000H unsigned integer
Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
Pixel Aspect Ratio | (0028,0034) | 1 | Ratio of the vertical size and horizontal size of the pixels in the image specified by a pair of integer values where the first value is the vertical pixel size, and the second value is the horizontal pixel size.
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. See PS3.5 for further explanation. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Enumerated Values: 8 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. See PS3.5 for further explanation. Enumerated Values: 7 if Bits Stored (0028,0101) = 8 15 if Bits Stored (0028,0101) = 16
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression. Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. See Section C.7.6.1.1.5 for further explanation.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Burned In Annotation | (0028,0301) | 1 | Indicates that the image does not contain burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Recognizable Visual Features | (0028,0302) | 1 | Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES ### Note Corneal topography is similar to finger prints as it is unique to individuals. Therefore, it could be used by a trained person or an expert system to identify the patient.
Image Laterality | (0020,0062) | 1 | Laterality of object imaged (as described in Anatomic Region Sequence (0008,2218)) examined. Enumerated Values: R right eye L left eye ### Note This Attribute is mandatory, in order to ensure that images may be positioned correctly relative to one another for display. Shall be consistent with any laterality information contained in Primary Anatomic Structure Modifier Sequence (0008,2230), if present. ### Note Laterality (0020,0060) is a Series level Attribute and must be the same for all Images in the Series, hence it must be absent.
Include Table C.7.6.16-12 “Real World Value Mapping Macro Attributes” | Defined CID for Measurement Units Code Sequence is 4267
Include Table 10-5 “General Anatomy Mandatory Macro Attributes” | The concept code for Anatomic Region Sequence (0008,2218) shall be (T-AA000, SRT, "Eye"), and Defined CID 244 “Laterality” shall be used for Anatomic Region Modifier Sequence (0008,2220). Defined CID 4266 “Ophthalmic Anatomic Structure Reference Point” shall be used for Primary Anatomic Structure Sequence (0008,2228). Only a single Item shall be permitted in this sequence. ### Note Although Primary Anatomic Structure Sequence (0008,2228) is Type 3, it is important to convey this information if able to be determined.

##### C.8.30.2.1 Corneal Topography Map Image Module Attribute Descriptions

###### C.8.30.2.1.1 Image Type

For Corneal Topography Maps, Image Type (0008,0008) is specified to be Type 1.

Defined Terms for Image Type Value 3:

CORNEAL_TOPO

  Identifies a topographic map of the cornea

###### C.8.30.2.1.2 Corneal Topography Map Real World Value and Image Transformations

The Corneal Topography Map SOP Class supports a sequence of transformations that completely define the conversion of a stored image into a displayed image.

The sequence of transformations from corneal measurements to a displayable image is explicitly defined in Figure C.8.30.2.1-1. Figure C.8.30.2.1-1 also conveys the transformation to display the scaling of the color map using its Real World Value Macro (see Table C.7.6.16-12 for more details on the Real World Value Macro).

Figure C.8.30.2.1-1. Corneal Topography Map Real World Value and Image Transformation Pipeline

An SCP of the Corneal Topography Map Storage SOP Class, when rendering SOP Instances of the Class shall apply the image transformations (i.e., Palette Color LUT) and the Real World Value LUT to display the annotated color scale. The annotated color scale shall conform to the "ISO Standard 19980 - Ophthalmic instruments - Corneal topographers, second edition, section B.4 Standardized colour Scale."

#### C.8.30.3 Corneal Topography Map Analysis Module

Table C.8.30.3-1 specifies the Attributes that describe the corneal Topography map analysis.

Table C.8.30.3-1. Corneal Topography Map Analysis Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Ophthalmic Mapping Device Type | (0022,1415) | 1 | Describes the type of ophthalmic mapping acquisition device. See Section C.8.30.3.1.1 for further explanation. Defined Terms: REFLECTION Reflection topography (i.e., placido, grid, etc.) SLIT_BASED Slit based elevation tomography INTERFEROMETRY E.g., Optical coherence tomography
Corneal Vertex Location | (0046,0202) | 1 | Location of the corneal vertex. This is used for the reference point for other Attributes within this SOP Instance and determined by the Image referenced in the Attribute Source Image Sequence (0008,2112). Given as column\row. Column is the horizontal offset and row is the vertical offset. Image relative position specified with sub-pixel resolution such that the origin at the Top Left Hand Corner (TLHC) of the TLHC pixel is 0.0\0.0, the Bottom Right Hand Corner (BRHC) of the TLHC pixel is 1.0\1.0, and the BRHC of the BRHC pixel is Columns\Rows (see Figure C.10.5-1). The values must be within the range 0\0 to Columns\Rows. This location shall anchor the corneal vertex at the x, y and z coordinates of 0.0, 0.0, 0.0, in mm. See Section C.8.30.3.1.4 for further explanation.
Corneal Topography Surface | (0046,0201) | 1 | Identifies the surface of the corneal topography map. Enumerated Values: A Anterior P Posterior
Pupil Centroid X-Coordinate | (0046,0203) | 1C | The horizontal coordinate of the centroid of the pupil relative to location of the cornea vertex specified in the Attribute Corneal Vertex Location (0046,0202), in mm, such that toward the right is positive. See Section C.8.30.3.1.4 for further explanation. Required if Attribute Corneal Topography Surface (0046,0201) is A (Anterior). ### Note This Attribute is conveyed in mm from the corneal vertex because display applications will have zoom and 3-D rotational capabilities.
Pupil Centroid Y-Coordinate | (0046,0204) | 1C | The vertical coordinate of the centroid of the pupil relative to location of the cornea vertex specified in the Attribute Corneal Vertex Location (0046,0202), in mm, such that up is positive. See Section C.8.30.3.1.4 for further explanation. Required if Attribute Corneal Topography Surface (0046,0201) is A (Anterior). ### Note This Attribute is conveyed in mm from the corneal vertex because display applications will have zoom and 3-D rotational capabilities.
Equivalent Pupil Radius | (0046,0205) | 1C | The average physical distance in mm from the pupil centroid specified in the Attributes Pupil Centroid X-Coordinate (0046,0203) and Pupil Centroid Y-Coordinate (0046,0204) to the measured perimeter of the pupil. Required if Attribute Corneal Topography Surface (0046,0201) is A (Anterior). ### Note When the pupil is not able to be determined the typical estimate is 4mm.
Vertices of the Outline of Pupil | (0046,0208) | 1C | A set of row/column vertices that outline the perimeter of the pupil. Two or more pairs of values follow and are the row and column coordinates of the other vertices that outline the perimeter of the pupil. For a two dimensional curve: X1, Y1, X2, Y2, etc. The first (X) dimension corresponds to the image column (horizontal offset), and the second (Y) dimension corresponds to the image row (vertical offset). This is a Polyline and the points are to be interpreted as an n-tuple list of end points between which straight lines are to be drawn. Required if Attribute Corneal Topography Surface (0046,0201) is A (Anterior).
Include Table C.8.25.10-2 “Keratometric Measurements Macro Attributes” |
Minimum Keratometric Sequence | (0046,0215) | 1 | A sequence that specifies the lowest power obtained when averaging individual meridian. Only one item shall be permitted. ### Note The measurement is typically taken at 3-4 mm from the corneal vertex.
>Radius of Curvature | (0046,0075) | 1 | The radius of curvature of the principal meridian of the cornea, measured in mm.
>Keratometric Power | (0046,0076) | 1 | The refractive power of the cornea at the principal meridian, measured in diopters.
>Keratometric Axis | (0046,0077) | 1 | The meridian where the keratometric radius of curvature or power is measured, measured in degrees.
Simulated Keratometric Cylinder Sequence | (0046,0218) | 1 | A sequence that specifies simulated keratometric cylinder power of the corneal surface, measured in diopters. Only one item shall be permitted. ### Note This information is obtained from the Steep and Flat Keratometric Axis readings.
>Keratometric Power | (0046,0076) | 1 | The refractive power of the cornea at the principal meridian, measured in diopters.
>Keratometric Axis | (0046,0077) | 1 | The meridian where the keratometric cylinder or power is measured, measured in degrees.
Average Corneal Power | (0046,0220) | 1 | The area-corrected average of the corneal power ahead of the entrance pupil, measured in diopters. ### Note It is generally equal to the keratometric spherical equivalent except for decentered refractive surgical procedures. It is used in intraocular lens calculations.
Corneal I-S Value | (0046,0224) | 1 | Quantifies the inferior-superior dioptric asymmetry along the vertical meridian to discriminate Keratoconus, measured in diopters. ### Note See Rabinowitz YS and McDonnell PJ. "Computer-assisted corneal topography in keratoconus. Refract Corneal Surg. 1989 Nov-Dec;5(6):400-8". If I-S > 1.4 D, the cornea may be classified as Keratoconus Suspect. If I-S > 1.9, enough asymmetry is present in the topography to classify the cornea as clinical Keratoconus.
Analyzed Area | (0046,0227) | 1 | The corneal surface area that can be analyzed, measured in mm squared.
Maximum Corneal Curvature Sequence | (0046,0211) | 3 | A Sequence to convey the maximum curvature and location of the measured corneal topography. Only a single Item is permitted in this sequence.
>Maximum Corneal Curvature | (0046,0212) | 1 | Maximum curvature in diopters of the measured corneal topography.
>Maximum Corneal Curvature Location | (0046,0213) | 1 | Location of the corneal maximum curvature. Given as column\row. Column is the horizontal offset and row is the vertical offset. Image relative position specified with sub-pixel resolution such that the origin at the Top Left Hand Corner (TLHC) of the TLHC pixel is 0.0\0.0, the Bottom Right Hand Corner (BRHC) of the TLHC pixel is 1.0\1.0, and the BRHC of the BRHC pixel is Columns\Rows (see Figure C.10.5-1). The values must be within the range 0\0 to Columns\Rows.
Surface Regularity Index | (0046,0230) | 3 | Measures local fluctuations in corneal power (i.e., irregular astigmatism) over the pupil (no units). ### Note This value would be about 0.4 for a cornea with good optical quality; at 1.5 and higher, vision falls below normal calculations.
Surface Asymmetry Index | (0046,0232) | 3 | This index sums the meridional mire-to-mire power changes over the entire corneal surface, increasing as topographic irregularities increase (no units).
Corneal Eccentricity Index | (0046,0234) | 3 | Index used to measure the eccentricity of the cornea (no units).
Keratoconus Prediction Index | (0046,0236) | 3 | Index used to indicate the presence of Keratoconus (no units) ### Note It is obtained by discrete analysis of the corneal topographic data. (e.g., Invest Ophthalmol Vis Sci 35:2749-2757, 1994).
Decimal Potential Visual Acuity | (0046,0238) | 3 | The range of best spectacle-corrected distance that might be expected from a functionally normal eye with the topographical characteristics of the analyzed cornea, measured in decimal. ### Note Typical examples: reference standard is 1, severe vision loss is 0.1. See Annex RR “Ophthalmic Refractive Reports Use Cases (Informative)” in PS3.17 for guidance in converting Decimal Potential Visual Acuity to other customarily used display notation such as 20/20 in the US and 6/6 in Britain.
Corneal Topography Map Quality Evaluation | (0046,0242) | 1C | Identifies the quality of the topography examination. Enumerated Values: ACCEPTABLE MARGINAL NOT_ACCEPTABLE Required if a quality rating value exists for the corneal topography map
Corneal Topography Map Type Code Sequence | (0046,0207) | 1 | The type of corneal topography map encoded in this SOP Instance. It specifies the meaning of the pixel values. Only a single Item shall be permitted in this sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | Defined CID 4268 “Corneal Topography Map Value Type”
Corneal Topography Mapping Normals Sequence | (0046,0210) | 1C | Identifies the data set used for corneal topography mapping values from a normative data base. Required if a normative data base was used. Only a single Item shall be permitted in this sequence.
>Include Table 10-22 “Data Set Identification Macro Attributes” |
Source Image Sequence | (0008,2112) | 1 | The Image SOP Class/Instance pair of the Image that was used to generate this corneal topography map. ### Note Attribute Corneal Vertex Location (0046,0202) in this corneal topography map has been generated by the source image and provides the registration of the Corneal Topography Map to the Source Image. See Section C.8.30.3.1.2 for further explanation. Only a single Item shall be permitted in this sequence.
>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
>Purpose of Reference Code Sequence | (0040,A170) | 1 | Describes the purpose for which the reference is made, (i.e., the role the source image or frame(s) played in the generation of this image). Only a single Item shall be permitted in this sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | The code used shall be (121322, DCM, "Source image for image processing operation").
Source Image Corneal Processed Data Sequence | (0046,0244) | 1 | Attributes that contain various power, elevation and wavefront measurements at specific points on the cornea of the SOP Instance referenced in Attribute Source Image Sequence (0008,2112). The Attributes are obtained from measurements of curvature or shape of the cornea. See Section C.8.30.3.1.3 for further explanation. One or more Items shall be present.
>Corneal Point Location | (0046,0247) | 1 | The x, y, and z coordinate of a point in the image within the cornea, in mm. Where the origin is conveyed by the Attribute Corneal Vertex Location (0046,0202). ### Note For two dimensional maps z=0.
>Corneal Point Estimated | (0046,0248) | 1 | The point defined in Attribute Corneal Point Location (0046,0247) is an estimated point (i.e., interpolated or extrapolated; not an actual measured point). Enumerated Values: Y Yes N No
>Axial Power | (0046,0249) | 1 | Conveys corneal shape characteristics, in diopters. It is determined from the curvature, r in mm, of the equivalent sphere with the same slope at a given point on the surface. Axial power = Km/r, where Km is the Keratometric Index.
>Tangential Power | (0046,0250) | 1 | Determined from the curvature (2nd derivative = d2y/dx2) of a point on the cornea, in diopters; also called Instantaneous Power. Emphasizes irregular astigmatism (large variations in higher order aberrations).
>Refractive Power | (0046,0251) | 1 | Conveys the optical refraction properties of the cornea, in diopters. It is determined from ray tracing using Snell's Law to calculate the true refractive power. ### Note It is used to evaluate ocular optics.
>Relative Elevation | (0046,0252) | 1 | Relative elevation, in micrometers, is calculated from the corneal surface distance from a reference surface (i.e., a sphere or ellipsoid) that intersects the corneal vertex. This value is determined from z - zref. Where z is conveyed in Attribute Corneal Point Location (0046,0247) and zref is the elevation of the reference surface.
>Corneal Wavefront | (0046,0253) | 1 | Corneal wavefront, in micrometers, is calculated from the elevation data by fitting with the Zernike Series expansion. ### Note This permits measurement of both low and higher order aberrations and provides the total amount of distortion of the Corneal Wavefront with a Root Mean Square (RMS) value.

##### C.8.30.3.1 Corneal Topography Map Analysis Module Attribute Descriptions

###### C.8.30.3.1.1 Ophthalmic Mapping Device Type

For Ophthalmic Mapping Device Type (0022,1415), Reflection corneal topography, which measures corneal curvature directly, is based on the reflection of a specific pattern from the corneal surface. Placido-based topographers use variations of circular mires, while grid-based topographers use a rectangular array of point reflections. Slit-based corneal tomography, which measures elevation directly, is based on the projection of multiple slit beams in succession through the cornea (and anterior segment). Some use the Schiempflug optical principle to achieve high resolution over a broad depth of field. Swept source OCT uses high speed scanning to produce its optical sections. Source images for these devices are shown in Figure C.8.30.3.1-1. Example A and B are for reflection types, C is an interferometry type, and D is a slit based type.

Figure C.8.30.3.1-1. Device types: A. Placido; B. Grid; C. OCT; D. Slit Based

###### C.8.30.3.1.2 Source Image Sequence

Equipment generating a corneal topography map image first obtains a source image. This image may be single frame or multi-framed such as when the Attribute Ophthalmic Mapping Device Type (0022,1415) is SLIT_BASED or INTERFEROMETRY. From this source image, the necessary measurement data is obtained to build the corneal topography map.

A typical source image may be generated by the Ophthalmic Photography 8 bit or 16 bit SOP Classes for device types of REFLECTION and SLIT_BASED. A typical source image for device type of INTERFEROMETRY would be Ophthalmic Tomography Image SOP Class.

Figure C.8.30.3.1-2 illustrates an example where the source image (left) is generated using a device type of REFLECTION. The corneal topography map and color scale is shown in the center (this is the output of this SOP Class). The right figure shows an example of the corneal topography map and color scale superimposed on the source image.

Figure C.8.30.3.1-2. Source Image (left), Corneal Topography Map Image (Center), Corneal Topography Map Presented as an Overlay on the Source Image (right)

###### C.8.30.3.1.3 Source Image Corneal Processed Data Sequence

The Source Image Corneal Processed Data Sequence (0046,0244) provides power, elevation and wavefront measurements taken at specific points of the Source Image. These Attributes were used to generate the corneal topography map and indices of this SOP Instance. This processed data can also be used to generate other corneal topography maps and indices.

###### C.8.30.3.1.4 Corneal Vertex Location

The Corneal Vertex Location (0046,0202) establishes the reference point for the corneal vertex. It is used as the frame of reference that establishes the spatial relationship for the corneal vertex (i.e., used within corneal topography maps) for a set of Images within a Series. It also allows Images across multiple Series to share the same corneal vertex Frame Of Reference. The corneal vertex is the point located at the intersection of the patient's line of sight (visual axis) and the corneal surface. It is represented by the corneal light reflex when the cornea is illuminated coaxially with fixation.

### Note

Since the criteria used to group images into a Series is application specific, it is possible for imaging applications to define multiple Series within a Study that share the same imaging space. Therefore the images with the same Frame of Reference UID (0020,0052) Attribute value share the same corneal vertex location within the patient's eye.

Figure C.8.30.3.1-3 illustrates the representation of corneal topography. The corneal vertex lies at the center of the rulers. Typical circular grids are 3, 5, 7, and 9 mm diameters centered on the vertex. The annotations in Figure C.8.30.3.1-3 are R, right; L, left; H = Head; F = Foot.

Figure C.8.30.3.1-3. Representation of Corneal Topography

Numerical position data shall use the Cartesian (i.e., two dimensional rectangular) coordinate system. The direction of the axes are determined by Patient Orientation (0020,0020), see Section C.7.6.1.1.1 for further explanation.

Devices that internally capture data in polar coordinates will need to convert to Cartesian coordinates, see Figure C.8.30.3.1-4.

Figure C.8.30.3.1-4. Sample Coordinate Data Points

When using the 3 dimensional coordinates (X, Y, Z), the Z axis shall represent corneal elevation. Z shall be measured from the length of a vector normal to the plane that is normal to and intersects the corneal vertex at the intersection of the x, y, z, axes. It is shown in the diagram as "+" (0.0, 0.0, 0.0). The Z axis shall be positive towards the anterior direction of the eye; (i.e., it is a right-hand rule coordinate system. Thus the Z values (see Figure C.8.30.3.1-5) will be predominantly negative, as they are posterior to the plane of the corneal vertex.

Figure C.8.30.3.1-5. Schematic of the 3-Dimensional Representation of Corneal Elevation

### C.8.31 Breast Projection Image Modules

#### C.8.31.1 Enhanced Mammography Image Module

Table C.8.31-1 specifies the Attributes that identify and describe general information about the Enhanced Mammography Image Module.

Table C.8.31-1. Enhanced Mammography Image Module Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Positioner Motion | (0018,1500) | 1 | Describes the activity of the X-Ray Source during acquisition. See C.8.31.1.1 for Defined Terms.
Positioner Type | (0018,1508) | 1 | Enumerated Values: MAMMOGRAPHIC
Content Qualification | (0018,9004) | 1 | Enumerated Values: PRODUCT RESEARCH SERVICE See C.8.13.2.1.1 for further explanation.
Acquisition DateTime | (0008,002A) | 1 | The date and time that the acquisition of data that resulted in this image started. ### Note The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Acquisition Duration | (0018,9073) | 1 | The time in seconds needed for the compete acquisition. See C.7.6.16.2.2.1 for further explanation.
Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
KVP | (0018,0060) | 1 | Average of the peak kilo voltage outputs of the X-Ray generator used for all frames.
X-Ray Tube Current in mA | (0018,9330) | 1C | Average of the nominal X-Ray tube currents in milliamperes for all frames. Required if Exposure in mAs (0018,9332) is not present. May be present otherwise.
Exposure Time in ms | (0018,9328) | 1C | Total (cumulative) duration of X-Ray exposure for all acquired frames in milliseconds. Required if Exposure in mAs (0018,9332) is not present. May be present otherwise.
Exposure in mAs | (0018,9332) | 1C | The total (cumulative) exposure for all acquired frames expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current. Required if either Exposure Time in ms (0018,9328) or X-Ray Tube Current in mA (0018,9330) is not present. May be present otherwise.
Focal Spot(s) | (0018,1190) | 1 | Nominal focal spot size in mm used to acquire all frames.
Anode Target Material | (0018,1191) | 1 | The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
Body Part Thickness | (0018,11A0) | 1 | The average thickness in mm of the body part examined when compressed, if compression has been applied during exposure.
Compression Force | (0018,11A2) | 1 | The compression force applied to the body part during exposure, measured in Newtons.
Paddle Description | (0018,11A4) | 1 | Description of the compression paddle, if compression was applied to the body part during exposure.
Exposure Control Mode | (0018,7060) | 1 | Type of exposure control Defined Terms: AUTOMATIC MANUAL
Exposure Control Mode Description | (0018,7062) | 1 | Text description of the mechanism of exposure control. May describe the number and type of exposure sensors or position of the sensitive area of the imaging detector.
Patient Orientation | (0020,0020) | 1C | Patient direction of the rows and columns of the most representative frame. Required if View Code Sequence (0054,0220) has an Item value other than one representing a specimen image. May be present otherwise.
Image Comments | (0020,4000) | 3 | User-defined comments about the image.
Samples per Pixel | (0028,0002) | 1 | Number of samples (planes) in this image. Enumerated Values: 1
Photometric Interpretation | (0028,0004) | 1 | Specifies the intended interpretation of the pixel data. Enumerated Values: MONOCHROME1 MONOCHROME2
Bits Allocated | (0028,0100) | 1 | Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values: 8 16
Bits Stored | (0028,0101) | 1 | Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. Enumerated Values: 8 9 10 11 12 13 14 15 16
High Bit | (0028,0102) | 1 | Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall have an Enumerated Value of one less than the value of Bits Stored (0028,0101).
Pixel Representation | (0028,0103) | 1 | Data representation of the pixel samples. Each sample shall have the same pixel representation. Enumerated Values: 0000H unsigned integer
Quality Control Image | (0028,0300) | 3 | Indicates whether or not this image is a quality control of phantom image. Enumerated Values: YES NO
Burned in Annotation | (0028,0301) | 1 | Indicates whether or not the image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values: NO
Lossy Image Compression | (0028,2110) | 1 | Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values: 00 Image has NOT been subjected to lossy compression. 01 Image has been subjected to lossy compression. Once this value has been set to 01 it shall not be reset. See Section C.7.6.1.1.5.
Lossy Image Compression Ratio | (0028,2112) | 1C | Describes the approximate lossy compression ratio(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Method (0028,2114). ### Note For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. For historical reasons, the lossy compression ratio may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Lossy Image Compression Method | (0028,2114) | 1C | A label for the lossy compression method(s) that have been applied to this image. See Section C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of Lossy Image Compression Ratio (0028,2112). ### Note For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) is "01".
Organ Dose | (0040,0316) | 1 | Organ dose value measured in dGy representing the collective total for all acquired frames. ### Note This may be an estimated value.
Entrance Dose in mGy | (0040,8302) | 1 | Entrance dose value measured in mGy at the surface of the patient representing the collective total for all acquired frames. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
Type of Detector Motion | (0054,0202) | 1 | Describes the activity of the Detector during acquisition. See C.8.31.1.1 for Defined Terms.
Icon Image Sequence | (0088,0200) | 3 | This icon image is representative of the Image. Only a single Item is permitted in this Sequence.
>Include Table C.7-11b “Image Pixel Macro Attributes” | See C.7.6.1.1.6 for further explanation.
Presentation LUT Shape | (2050,0020) | 1 | Specifies a transformation for the Presentation LUT such that the output of all grayscale transformations, if any, is defined to be in P-Values. Enumerated Values: IDENTITY output is in P-Values; shall be used if Photometric Interpretation (0028,0004) is MONOCHROME2. INVERSE output after inversion is in P-Values; shall be used if Photometric Interpretation (0028,0004) is MONOCHROME1.

##### C.8.31.1.1 Positioner and Detector Motion Attribute Descriptions

Positioner Motion (0018,1500) and Type of Detector Motion (0054,0202) shall have the Defined Terms specified in Table C.8.31.1.1-1.

Table C.8.31.1.1-1. Types of Positioner and Detector Motion

STATIONARY | No motion
ROTATION_STEP | Circular arc motion, stepped, acquire only while stationary
ROTATION_CONT | Circular arc motion, continuous during acquisition
TRANSLATION_STEP | Linear motion, stepped, acquire only while stationary
TRANSLATION_CONT | Linear motion, continuous during acquisition
COMPLEX_STEP | Complex motion, stepped, acquire only while stationary
COMPLEX_CONT | Complex motion, continuous during acquisition

Complex motion is defined as that which is not simply described by linear translation or rotation around an axis.

#### C.8.31.2 Breast X-Ray Positioner Macro

Table C.8.31.2-1 specifies the Attributes of the Breast X-Ray Positioner Functional Group Macro.

Table C.8.31.2-1. Breast X-Ray Positioner Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Positioner Position Sequence | (0018,9405) | 1 | A sequence that describes the geometrical position of the positioner. Only a single Item shall be included in this sequence.
>Positioner Primary Angle | (0018,1510) | 1C | Signed position in degrees of the X-Ray beam vector in the coronal anatomical plane as if the patient were standing facing the equipment where vertical is zero. Required if X-Ray source can be moved in the coronal anatomical plane. May be present otherwise.
>Positioner Primary Angle Direction | (0018,9559) | 1C | The interpretation of the sign of the Positioner Primary Angle (0018,1510). Enumerated Values: CW Clockwise. Positioner Primary Angle movement is positive when movement is from vertical to the patient's right (with patient standing, facing the equipment). CC Counter-clockwise. Positioner Primary Angle is positive when movement is from vertical to the patient's left (with patient standing, facing the equipment). See Figure C.8.31.2-1. Required if Positioner Primary Angle (0018,1510) is present.
>Positioner Secondary Angle | (0018,1511) | 1C | Position in degrees of the X-Ray beam vector in the sagittal anatomical plane as if the patient were standing where movement of the X-Ray source from anterior to posterior is positive, and vertical is zero. Required if the X-Ray source can be moved in the sagittal anatomical plane. May be present otherwise.

##### C.8.31.2.1 Breast X-Ray Positioner Attribute Descriptions

Figure C.8.31.2-1 illustrates the Defined Terms for Positioner Primary Angle Direction (0018,9559), indicating which C-arm movement direction defines a positive value for Positioner Primary Angle (0018,1510).

Figure C.8.31.2-1. Illustration of Positioner Primary Angle Direction

#### C.8.31.3 Breast X-Ray Detector Macro

Table C.8.31.3-1 specifies the Attributes of the Breast X-Ray Detector Functional Group Macro.

Table C.8.31.3-1. Breast X-Ray Detector Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Detector Position Sequence | (0018,9541) | 1 | A sequence that describes the geometrical position of the detector. Only a single Item shall be included in this sequence.
>Detector Primary Angle | (0018,1530) | 1C | Angle of the X-Ray beam in the row direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted toward higher numbered columns. Negative values indicate that the X-Ray beam is tilted toward lower numbered columns. See C.8.11.7.1.2. Required if the detector can be moved in the row direction. May be present otherwise.
>Detector Secondary Angle | (0018,1531) | 1C | Angle of the X-Ray beam in the column direction in degrees relative to the normal to the detector plane. Positive values indicate that the X-Ray beam is tilted toward lower numbered rows. Negative values indicate that the X-Ray beam is tilted toward higher numbered rows. See C.8.11.7.1.2. Required if the detector can be moved in the column direction. May be present otherwise.

#### C.8.31.4 Breast X-Ray Geometry Macro

Table C.8.31.4-1 specifies the Attributes of the Breast X-Ray Geometry Functional Group Macro.

Table C.8.31.4-1. Breast X-Ray Geometry Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray Geometry Sequence | (0018,9476) | 1 | Sequence containing the geometric properties for this frame or set of frames. Only a single Item shall be included in this sequence.
>Distance Source to Detector | (0018,1110) | 1C | Distance in mm from source to detector center on the chest wall line. Required if Presentation Intent Type (0008,0068) = FOR PROCESSING. May be present otherwise. ### Note This value is traditionally referred to as Source Image Distance (SID). See C.8.11.7.1.1.
>Distance Source to Patient | (0018,1111) | 1C | Distance in mm from source to the Breast Support side that is closest to the Imaging Subject, as measured along the X-Ray beam vector. Required if Presentation Intent Type (0008,0068) = FOR PROCESSING. May be present otherwise. ### Note This value is traditionally referred to as Source Object Distance (SOD). See notes for this attribute in C.8.11.5. See C.8.11.7.1.1 for description of X-Ray beam vector.
>Distance Source to Isocenter | (0018,9402) | 1C | Distance from source to isocenter in mm. Required if Presentation Intent Type (0008,0068) = FOR PROCESSING. May be present otherwise.
>Distance Source to Entrance | (0040,0306) | 3 | Distance in mm from the source to the surface of the patient closest to the source during the acquisition of this image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.
>Estimated Radiographic Magnification Factor | (0018,1114) | 1 | Ratio of Source Image Distance (SID) over Source Object Distance (SOD).

#### C.8.31.5 Breast X-Ray Acquisition Dose Macro

Table C.8.31.5-1 specifies the Attributes of the X-Ray Acquisition Dose Functional Group Macro.

Table C.8.31.5-1. Breast X-Ray Acquisition Dose Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray Acquisition Dose Sequence | (0018,9542) | 1 | Sequence containing the X-Ray exposure information for this frame. Only a single Item shall be included in this sequence.
>Exposure Time in ms | (0018,9328) | 1 | Duration of X-Ray exposure in milliseconds.
>Exposure in mAs | (0018,9332) | 1 | The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
>Relative X-Ray Exposure | (0018,1405) | 3 | Indication of the applied dose, in manufacturer specific units. ### Note This value is intended to provide a single location where manufacturer specific information can be found for annotation on a display or film, that has meaning to a knowledgeable observer. This may be a calculated or measured value. Examples are the detector entrance dose (KB) , the CR sensitivity value (S), or the logarithmic median (lgM). DICOM specifies standard Attributes in Table 10-23 “Exposure Index Macro Attributes”, which are recommended.
>Half Value Layer | (0040,0314) | 3 | The thickness of Aluminum in mm required to reduce the X-Ray Output (0040,0312) by a factor of two. ### Note This value may be a calibrated value rather than measured during the exposure.
>Organ Dose | (0040,0316) | 1 | Average organ dose value measured in dGy during the acquisition of this image. ### Note This may be an estimated value.
>Entrance Dose in mGy | (0040,8302) | 1 | Average entrance dose value measured in mGy at the surface of the patient during the acquisition of this image. ### Note This may be an estimated value based on assumptions about the patient's body size and habitus.

#### C.8.31.6 Breast X-Ray Isocenter Reference System Macro

Table C.8.31.6-1 specifies the Attributes of the Breast X-Ray Isocenter Reference System Functional Group Macro.

Table C.8.31.6-1. Breast X-Ray Isocenter Reference System Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Isocenter Reference System Sequence | (0018,9462) | 1 | A sequence that describes the Isocenter Reference Coordinate System (O, X, Y, Z). Only a single Item shall be included in this sequence.
>X-Ray Source Isocenter Primary Angle | (0018,9543) | 1 | Primary angle of the X-Ray source in the isocenter reference system (deg). See C.8.31.6.1.2 for further explanation.
>X-Ray Source Isocenter Secondary Angle | (0018,9544) | 1 | Secondary angle of the X-Ray source in the isocenter reference system (deg). See C.8.31.6.1.2 for further explanation.
>Breast Support Isocenter Primary Angle | (0018,9545) | 1 | Primary angle of the Breast Support in the isocenter reference system (deg). See C.8.31.6.1.3 for further explanation.
>Breast Support Isocenter Secondary Angle | (0018,9546) | 1 | Secondary angle of the Breast Support in the isocenter reference system (deg). See C.8.31.6.1.3 for further explanation.
>Breast Support X Position to Isocenter | (0018,9547) | 1C | X position of the Breast Support Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.3 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Breast Support Y Position to Isocenter | (0018,9548) | 1C | Y position of the Breast Support Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.3 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Breast Support Z Position to Isocenter | (0018,9549) | 1C | Z position of the Breast Support Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.3 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Detector Isocenter Primary Angle | (0018,9550) | 1 | Primary angle of the Detector in the isocenter reference system (deg). See C.8.31.6.1.4 for further explanation.
>Detector Isocenter Secondary Angle | (0018,9551) | 1 | Secondary angle of the Detector in the in the isocenter reference system (deg). See C.8.31.6.1.4 for further explanation.
>Detector X Position to Isocenter | (0018,9552) | 1C | X position of the Detector Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.4 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Detector Y Position to Isocenter | (0018,9553) | 1C | Y position of the Detector Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.4 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Detector Z Position to Isocenter | (0018,9554) | 1C | Z position of the Detector Reference Point with respect to the Isocenter (mm). See C.8.31.6.1.4 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Detector Active Area TLHC Position | (0018,9557) | 1C | The x, y, and z coordinates in mm of the center of the top left hand corner detector element of the detector active area in the Detector coordinate system. See C.8.31.6.1.5 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.
>Detector Active Area Orientation | (0018,9558) | 1C | The direction cosines of the first row and the first column with respect to the Detector coordinate system. See C.8.31.6.1.5 for further explanation. Required if Presentation Intent Type (0008.0068) = FOR PROCESSING. May be present otherwise.

##### C.8.31.6.1 Isocenter Reference System Attribute Descriptions

The Isocenter Reference System Attributes describe the 3D geometry of the X-Ray equipment composed by the X-Ray Source, Breast Support and the Detector.

These attributes define four coordinate systems in the 3D space:

- Isocenter coordinate system

- X-Ray Source coordinate system

- Breast Support coordinate system

- Detector coordinate system

The Isocenter Reference System attributes describe the relationship between the 3D coordinates of a point in the Breast Support coordinate system and the 3D coordinates of such point in the X-Ray Source and Detector coordinate systems (which may move in the equipment), by using the Isocenter coordinate system that is fixed in the equipment.

Unlike in X-Ray Angiography, in stereotactic biopsy and breast tomosynthesis the X-Ray source does not move in lock-step with the detector. The detector may be stationary, may translate, or may rotate as the X-Ray source moves. Thus for the purpose of stereotactic biopsy and breast tomosynthesis, the X-Ray Source and Detector Coordinate Systems are defined separately, and each of the potential detector positionings is considered separately.

### Note

Annex Z “X-Ray Isocenter Reference Transformations (Informative)” in PS3.17 describes the transformations necessary to transpose between coordinate systems.

The detector is anterior to the patient standing upright and facing the front of the gantry, as shown in Figure C.8.31.6-1.

Figure C.8.31.6-1. Patient/Detector Relationship (Patient Standing)

As breast projection X-Ray imaging traditionally uses devices with similar physical appearance, the following terms are defined for the purpose of helping later convey the geometry associated with breast projection X-Ray imaging:

GANTRY FRONT | The side of the equipment closest to the patient when the patient is standing, positioned for breast projection X-Ray imaging. | Figure C.8.31.6-2. Gantry Sides
GANTRY RIGHT | The right-hand side of the equipment when the patient is standing facing GANTRY FRONT.
GANTRY LEFT | The left-hand side of the equipment when the patient is standing facing GANTRY FRONT.
GANTRY REAR | The side of the equipment furthest from the patient when the patient is standing, positioned for breast projection X-Ray imaging.

###### C.8.31.6.1.1 Isocenter Coordinate System

The Isocenter coordinate system (O,X,Y,Z) of the equipment is defined as follows (see Figure C.8.31.6-3) :

- Origin O is the System Isocenter, which is the point where the plane of motion of the X-Ray Source spot intersects the axis of rotation of the X-Ray Source.

- +X direction is from GANTRY LEFT to GANTRY RIGHT in the horizontal plane (gravity plane).

- +Y direction is from GANTRY FRONT to GANTRY REAR in the horizontal plane (gravity plane).

- +Z direction is upward (anti-gravity).

- The isocenter coordinate system does not rotate when the tube head or C-arm rotates.

Figure C.8.31.6-3. Isocenter Coordinate System

###### C.8.31.6.1.2 X-Ray Source Coordinate System

The X-Ray Source coordinate system (Os, Xs, Ys, Zs) is defined as follows (see Figure C.8.31.6-4):

- Origin Os is identical to the origin of the Isocenter coordinate system O.

- Xs axis is in the plane normal to the axis of rotation of the X-Ray source through Os and is perpendicular to the X-Ray source. Positive direction is from GANTRY LEFT to GANTRY RIGHT when the X-Ray source is overhead (As1 equals 0°).

- Ys axis is the axis of rotation of the X-ray source. Positive direction is from GANTRY FRONT to GANTRY REAR.

- Zs axis is normal to the Xs Ys plane. The +Zs direction is generally toward the X-ray source, defined by the right-hand rule from +Xs and +Ys.

Figure C.8.31.6-4. X-Ray Source Coordinate System

The X-Ray Source coordinate system (Os, Xs, Ys, Zs) is characterized with respect to the Isocenter coordinate system (O, X, Y, Z), by two angles describing the X-Ray center beam. These angles are relative to the Isocenter reference system, and independent from the patient position on the equipment.

X-Ray Source Isocenter Primary Angle (0018,9543) (so-called As1 in Figure C.8.31.6-5) is defined as the angle between the YZ plane and the YZs plane. The angle from +Zs toward +Xs is positive.

X-Ray Source Isocenter Secondary Angle (0018,9544) (so-called As2 in Figure C.8.31.6-5) is defined as the angle between the XZ plane and the XZs plane. The angle from +Zs toward +Ys is positive.

Figure C.8.31.6-5. X-Ray Source Isocenter Angles

###### C.8.31.6.1.3 Breast Support Coordinate System

The Breast Support (see Figure C.8.31.6-6) is the housing over the detector onto which the breast is placed before imaging. For the purpose of this description, Breast Support top surface refers to the patient contact surface of the Breast Support, closest to the X-Ray source.

Figure C.8.31.6-6. Breast Support Orientation

The Breast Support coordinate system (Ob, Xb, Yb, Zb) is defined as follows (see Figure C.8.31.6-7):

- Origin Ob, the so-called Breast Support Reference Point, is an arbitary point, as defined by the equipment manufacturer, on the axis of the center of rotation of the Breast Support.

- Xb axis lies parallel to the Breast Support top surface, passes through Ob, and is parallel to X when the Breast Support top surface is normal to gravity. The +Xb direction is toward BREAST SUPPORT RIGHT.

- Yb axis lies parallel to the Breast Support top surface, passes through Ob, and is perpendicular to the Xb axis. The +Yb direction is toward BREAST SUPPORT ANTERIOR.

- Zb axis is normal to the Breast Support top surface and passes through Ob. The +Zb direction is toward BREAST SUPPORT HEAD.

The Breast Support coordinate system (Ob, Xb, Yb, Zb) is characterized, with respect to the Isocenter coordinate system (O, X, Y, Z), by two rotations that describe the Breast Support tilt and a 3D translation (see Figure C.8.31.6-7). It is the most common convention in breast projection X-Ray system design to have the Breast Support rotate identically and in synchronization with the system C-arm (they are most often rigidly integrated):

Breast Support Isocenter Primary Angle (0018,9545) (so-called Ab1) is defined as the angle between the YZ plane and the YZb plane. The angle is positive when the Breast Support Right end of the Breast Support is lower than the Breast Support Left end of the Breast Support, and is 0° when the Breast Support surface is normal to the +Z direction. In digital breast tomosynthesis, because the X-Ray source moves independently of the Breast Support, the Breast Support Isocenter Primary Angle is the principal place where the user's perception of the C-arm angle is encoded.

Breast Support Isocenter Secondary Angle (0018,9546) (so-called Ab2) is defined as the angle between the XY plane and the XYb plane. The angle is positive when the Breast Support Anterior side of the Breast Support is lower than the Breast Support Posterior end of the Breast Support, and is 0° when the Breast Support surface is normal to the +Z axis. In most breast projection X-Ray imaging equipment the value of Ab2 is 0°.

Figure C.8.31.6-7. Breast Support Angles with respect to the Isocenter Reference System

Breast Support X Position to Isocenter (0018,9547) (so-called BX) is defined as the translation of the Breast Support Reference Point Ob with respect to the Isocenter coordinate system in the +X axis direction. Breast support translation toward +X is positive.

Breast Support Y Position to Isocenter (0018,9548) (so-called BY) is defined as the translation of the Breast Support Reference Point Ob with respect to the Isocenter coordinate system in the +Y axis direction. Breast support translation toward +Y is positive.

Breast Support Z Position to Isocenter (0018,9459) (so-called BZ) is defined as the translation of the Breast Support Reference Point Ob with respect to the Isocenter coordinate system in the +Z axis direction. Breast support translation toward +Z is positive.

### Note

A translation of (BX, BY, BZ) = (0, 0, 0) means that the Breast Support Reference Point Ob is at the System Isocenter.

Figure C.8.31.6-8. Breast Support Translation with respect to the Isocenter Reference System

###### C.8.31.6.1.4 Detector Coordinate System

A detector coordinate system is defined that allows the detector to be either stationary or in motion. For clarity of understanding and interoperability, detector motion terms that may be used during image acquisition are defined, as indicated in Type of Detector Motion (0054,0202):

- Stationary Detector

- Rotating Detector

- Translating Detector

- Complex Detector

An infinite variation of detector motions is possible through time- and angle- dependent combinations of detector rotation and detector translation.

At any given point in time during image acquisition the detector origin Od may be translated with respect to the system isocenter and/or the detector coordinate system rotated with respect to the isocenter coordinate system. The detector coordinate system (Od, Xd, Yd, Zd) is defined as follows (see Figure C.8.31.6-9):

- Detector Reference Point Od, is an arbitrary point, defined by the equipment manufacturer, that lies on the axis of rotation of the detector, if any.

- Xd axis lies in the plane parallel to the detector surface, through the point Od, and perpendicular to the axis of rotation. The +Xd direction is in the same direction as the +X direction when the detector surface is normal to gravity.

- Yd axis is the axis of rotation of the detector and is parallel to Y. The +Yd direction is in the same direction as the +Y direction when the detector surface is normal to gravity.

- Zd axis is normal to the detector surface and through the point Od. The +Zd direction is upward, defined by the right-hand rule from +Xd and +Yd.

Figure C.8.31.6-9. Detector Coordinate System

The Detector coordinate system (Od, Xd, Yd, Zd) is characterized with respect to the Isocenter coordinate system (O, X, Y, Z), by two angles describing the tilt of the detector. These angles are relative to the Isocenter reference system, and independent from the patient position on the equipment.

Detector Isocenter Primary Angle (0018,9550) (so-called Ad1) is defined as the angle between the YZ plane and the YZd plane. The angle is positive when the +Xd axis is lower than the -Xd axis with respect to Z, and is 0°when the detector surface is normal to the +Z axis.

Detector Isocenter Secondary Angle (0018,9551) (so-called Ad2) is defined as the angle between the plane XZ and the plane XZd. The angle is positive when the +Yd axis is lower than the -Yd axis with respect to Z. In most cases this angle is 0°, inferring that the XZ plane is parallel to the Xd plane.

Figure C.8.31.6-10. Detector Isocenter Angles

Detector X Position to Isocenter (0018,9552) (so-called DX) is defined as the translation of the Detector Reference Point Od with respect to the Isocenter coordinate system in the X direction. A translation of DX toward Breast Support Right from Detector Od is positive.

Detector Y Position to Isocenter (0018,9553) (so-called DY) is defined as the translation of the Detector Reference Point Od with respect to the Isocenter coordinate system in the Y direction. A translation of DY toward Breast Support Anterior from Detector Od is positive.

Detector Z Position to Isocenter (0018,9554) (so-called DZ) is defined as the translation of the Detector Reference Point Od with respect to the Isocenter coordinate system in the Z direction. A translation of DZ toward Breast Support Head from Detector Od is positive.

Figure C.8.31.6-11. Translation of the Detector Coordinate System

Although not shown in Figure C.8.31.6-11, translation of the detector moves the Detector Origin Od relative to the Isocenter. Thus during translation of the detector, at least one of DX, DY and DZ will change.

### Note

A translation of (DX, DY, DZ) = (0, 0, 0) means that the Detector Reference Point Od is at the System Isocenter.

The case where the detector is stationary during image acquisition is a degenerate case, but still defined in the same manner.

### Note

1. An angulation of (Ad1, Ad2) = (0, 0) means that the Detector is not rotated relative to the System Isocenter coordinate system.

2. A translation of (DX, DY, DZ) = (0, 0, 0) means that the Detector Reference Point Od is at the System Isocenter.

###### C.8.31.6.1.5 Detector Active Area Relationship

The image and planes in conventional mammography and digital breast tomosynthesis are expressed in relation to Detector FOV and Detector Active area (see C.8.11.4.1.1). As manufacturers design their systems differently, the detector may be mounted or positioned differently in different breast imaging systems. As a result, the TLHC position of the Detector Active Area, together with row and column directions, must be specified (see Figure C.8.31.6-12). The relationship between the Detector Active Area TLHC, the row and column directions of the Active Area, and the Field of View and Detector Coordinate System (defined in C.8.31.6.1.4) is defined by two attributes.

- Detector Active Area TLHC Position (0018,9557) specifies the x, y and z cooordinates in mm of the center of the pixel defined as Detector Active Area TLHC within the Detector coordinate system, where the Z-direction value is always 0 since the detector itself is in XdYd plane. A value of Detector Active Area TLHC Position (0018,9557) = (0,0,0) means that the Detector Active Area TLHC Position is at the origin Od of the Detector coordinate system.

- Detector Active Area Orientation (0018,9558) specifies the direction cosines of the first row followed by the direction cosines of the first column within the Detector coordinate system. The first three values contain the cosine of the angle between the first row and the Xd, Yd and Zd axes, respectively. The next three values contain the cosine of the angle between the first column and the Xd, Y d and Zd axes, respectively.

Figure C.8.31.6-12. Examples of Detector Active Area TLHC Position and Orientation

In Figure C.8.31.6-12, the left picture illustrates Detector Active Area Orientation (0018,9558) = (0,-1,0,-1,0,0), while the right picture illustrates Detector Active Area Orientation (0018,9558) = (0,1,0,1,0,0).

##### C.8.31.7 X-Ray Grid Macro

Table C.8.31.7-1 specifies the Attributes of the X-Ray Grid Functional Group Macro.

Table C.8.31.7-1. X-Ray Grid Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray Grid Sequence | (0018,9555) | 1 | A sequence that describes the geometrical position of the positioner. Only a single Item shall be included in this sequence.
>Grid | (0018,1166) | 1 | Identified the grid. May be multi-valued. Defined Terms: FIXED FOCUSED RECIPROCATING PARALLEL CROSSED NONE
Include Table C.8-36b “X-Ray Grid Description Macro Attributes” |

##### C.8.31.8 X-Ray Filter Macro

Table C.8.31.8-1 specifies the Attributes of the X-Ray Filter Functional Group Macro.

Table C.8.31.8-1. X-Ray Filter Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
X-Ray Filter Sequence | (0018,9556) | 1 | A sequence that describes the attributes related to the filtration of X-Rays during image acquisition. Only a single Item shall be included in this sequence.
> Include Table C.8-35a “X-Ray Filtration Macro Attributes” |

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