DICOM PS3.17 2017b - Explanatory Information

GGGG.2 Dual-source CT Organ Radiation Dose Example
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## GGGG.2 Dual-source CT Organ Radiation Dose Example

The following example shows the report of the organ dose calculated for a dual-source CT scan.

The calculation uses a Radiation Dose SR provided by a CT system that has dual X-Ray tubes. The Radiation Dose SR is created during the acquisition of Neck DE_CAROTID CT scan of an adult male of 75 kg and 165 cm height.

The dose calculations are performed on the CT system. The dose calculation application generates a Patient Radiation Dose Structured Report document and a Dose Point Cloud containing an image of the dose distribution for the patient model.

The dose calculation application uses the following settings and assumptions:

- RDSR Source Data:

  - The Irradiation Events associated with the CT Localizer Radiograph are excluded.

  - The Irradiation Event UID from the helical CT series is used in the calculation of the organ dose.

- Patient Model:

  - The patient model is a stylized anthropomorphic model of the patient.

  - Organs are represented by simple geometric shapes described by mathematical equations. The parameters of the equations describing the location, shape, and dimension of the organs are stored in a DICOM SOP Instance.

  - In this example the gender and age of the patient are used to select the appropriate phantom from the existing phantom library.

- Patient Model Registration:

  - Image Content-based Alignment between the CT images Frame of Reference and the 3D stylized model Frame of Reference is used for registration.

- Beam Attenuators:

  - Additional Aluminum filtration is used in the methodology and the equivalent HVL for the scanner model used in the method is given.

Table GGGG.2-1. Dual-source CT Organ Radiation Dose Example

Node | Code Meaning of Concept Name | Code or Example Value | Comment
--- | --- | --- | ---
1 | Patient Radiation Dose Report |  | TID 10030
1.1 | Language of Content Item and Descendants | (En, IETF4646, "English") | TID 1204
1.1.1 | Country of Language | (CA, ISO3166_1, "Canada") | TID 1204
1.2 | Observer Type | (121007, DCM, "Device") | TID 1002
1.3 | Device Observer UID | 2.13.4.5.2.33.5 | TID 1004
1.4 | Device Observer Name | RUMC-213 | TID 1004
1.5 | Device Observer Manufacturer | Manufacturer DEX | TID 1004
1.6 | Device Observer Model Name | Scanner 4500 | TID 1004
1.7 | Radiation Dose Estimate |  | TID 10031
1.7.1 | Radiation Dose Estimate Name | Dual-source Neck DE_CAROTID CT scan Tube A&B | TID 10031
1.7.2 | Comment | Tube A and B combined | TID 10031
1.7.3 | Radiation Dose Estimation Methodology |  | TID 10033
1.7.3.1 | SR Instance Used |  | TID 10033
1.10.3.1 | SR Instance Used |  | Radiation Dose SR
1.10.3.1.1 | SOP Class UID | 1.2.840.1008.5.1.4.1.1.88.67 |
1.10.3.1.2 | SOP Instance UID | 1.2.3.4.566.77.1 |
1.7.3.1.1 | Event UID Used | 1.3.12.2.xxxxxx | TID 10033
1.7.3.2 | Patient Radiation Dose Model |  | TID 10033
1.7.3.2.1 | Patient Model Type | (128404, DCM, "Anthropomorphic Model") | TID 10033
1.7.3.2.2 | Radiation Transport Model Type | (128421, DCM, "Geometric Radiation Transport Model") | TID 10033
1.7.3.2.3 | Patient Radiation Dose Model Data | < UID of "Patient Radiation Dose Model Data"> | TID 10033
1.7.3.2.3 | Patient Radiation Dose Model Data |  | Parametric map
1.7.3.2.3.1 | SOP Class UID | 1.2.840.1008.5.1.4.1.1.30 |
1.7.3.2.3.2 | SOP Instance UID | 1.2.5.4.6.677 |
1.7.3.2.4 | Patient Radiation Dose Model Reference | Cristy et al. 1987 | TID 10033
1.7.3.2.5 | Patient Model Demographics |  | TID 10033
1.7.3.2.5.1 | Model Minimum Age | 18 (a, UCUM, "year") | TID 10033
1.7.3.2.5.2 | Model Maximum Age | 18 (a, UCUM, "year") | TID 10033
1.7.3.2.5.3 | Model Patient Sex | (M, DCM, "Male") | TID 10033
1.7.3.2.5.4 | Model Minimum Weight | 75 (kg, UCUM, "kilogram") | TID 10033
1.7.3.2.5.5 | Model Maximum Weight | 75 (kg, UCUM, "kilogram") | TID 10033
1.7.3.2.5.6 | Model Minimum Height | 165 (cm, UCUM, "Centimeter") | TID 10033
1.7.3.2.5.7 | Model Maximum Height | 165 (cm, UCUM, "Centimeter") | TID 10033
1.7.3.2.6 | Patient Model Registration |  | TID 10033
1.7.3.2.6.1 | Registration Method | (125024, DCM, "Image Content-based Alignment") | TID 10033
1.7.3.2.6.2 | Spatial Registration | <UID of "Spatial Registration"> | TID 10033
1.7.3.2.6.2.1 | SOP Class UID | 1.2.840. 1008.5.1.4.1.1.66.1 |
1.7.3.2.6.2.2 | SOP Instance UID | 1.4.9.87.11.223.5 |
1.7.3.3 | X-Ray Beam Attenuator |  | TID 10033
1.7.3.3.1 | Attenuator Category | (113771, DCM, "X-Ray Filters") | TID 10033
1.7.3.3.2 | Equivalent Attenuator Material | (C-120F9, SRT, "Aluminum or Aluminum compound") | TID 10033
1.7.3.3.3 | Equivalent Attenuator Thickness | 1.4 (mm, UCUM, "Millimeter") | TID 10033
1.7.3.3.4 | Attenuator Description | Mean equivalent Aluminum thickness of bowtie filter | TID 10033
1.7.3.3.5 | X-Ray Beam Attenuator Model |  | TID 10033
1.7.3.3.5.1 | Radiation Transport Model Type | (128421, DCM, "Geometric Radiation Transport Model") | TID 10033
1.7.3.4 | Radiation Dose Estimate Method |  | TID 10033
1.7.3.4.1 | Radiation Dose Estimate Method Type | (D009010, MSH, "Monte Carlo") | TID 10033
1.7.3.4.2 | Radiation Dose Estimate Parameters |  | TID 10034
1.7.3.4.2.1 | (111634, DCM, "Half Value Layer") | 8.5 (mm, UCUM, "Millimeter") | TID 10034
1.7.3.4.3 | Radiation Dose Estimate Method Reference | Simulation package XX version YY | TID 10033
1.7.4 | Radiation Dose Estimate Representation |  | TID 10032
1.7.4.1 | Distribution Representation | (128496, DCM, "Dose Point Cloud") | TID 10032
1.7.4.2 | Radiation Dose Representation Data |  | TID 10032
1.7.3.2.3.1 | SOP Class UID | 1.2.840.1008.5.1.4.1.1.30 | Parametric Map
1.7.3.2.3.2 | SOP Instance UID | 1.87.2.3.4.11.3 |
1.7.4.3 | Organ | (T-D0010, SRT, "Entire Body") | TID 10032
1.7.5 | Organ Radiation Dose Information |  | TID 10031
1.7.5.1 | Organ | (T-28000, SRT, "Lung") | TID 10031
1.7.5.1.1 | (DCM,128533, "Mean Absorbed Radiation Dose") | 9.6 (mGy, UCUM, "mGy") | TID 10031

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DICOM PS3.17 2017b - Explanatory Information