DICOM PS3.4 2020a - Service Class Specifications

K.6 SOP Class Definitions (Current)
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## K.6 SOP Class Definitions

### K.6.1 Modality Worklist SOP Class

#### K.6.1.1 Modality Worklist SOP Class Overview

The Modality Worklist SOP Class defined within the Basic Worklist Management Service Class defines an application-level class of service that facilitates the communication of information to the imaging modality about Scheduled Procedure Steps, and entities related to the Scheduled Procedure Steps. As will be detailed below, part of the information carried by the worklist mechanism is intended to be used by the imaging modality itself, but much of the information is intended to be presented to the modality operator.

This worklist is structured according to Scheduled Procedure Steps. A procedure step is a unit of service in the context of a requested imaging procedure.

The Modality Worklist SOP Class supports the following requirements:

- Verify patient (e.g., download patient demographic information from IS to Modality, to verify that the person to be examined is the intended subject).

- Select a Scheduled Procedure Step from the IS (e.g., download procedure step information from the IS to the Modality). The Modality Worklist SOP Class supports two alternatives for the realization of this requirement, supporting different organization methods of the department:

  - The Modality may obtain the list of Scheduled Procedure Steps from the IS. Display of the list and selection from the list is done at the Modality.

  - The list is displayed and selection is performed on the IS. This implies, that the information is obtained by the Modality just before the Scheduled Procedure Step starts.

- Prepare the performance of a Scheduled Procedure Step.

- Couple DICOM images unambiguously with related information from the IS (e.g., patient demographics, procedure description, ID data structure from the IS, contextual IS information).

- Capture all the Attributes from the IS, that are mandatory to be inserted into the DICOM Image Object

The Modality Worklist SOP Class is not intended to provide access to all IS information and services that may be of interest to a Modality operator or attending physician. Its primary focus is the efficient operation of the image acquisition equipment. DICOM SOP Classes such as the Relevant Patient Information Query SOP Class and non-DICOM Services that fall beyond the scope of the Modality Worklist SOP Class may be needed.

The Modality Worklist SOP Class does not support the transmission of information from the Modality to the information system.

#### K.6.1.2 Modality Worklist Information Model

##### K.6.1.2.1 E/R Model

In response to a given C-FIND request, the SCP might have to send several C-FIND responses, (i.e., one C-FIND response per matching worklist item). Each worklist item focuses on one Scheduled Procedure Step and the related information. The E-R diagram presented in Figure K.6-1 depicts the content of one C-FIND request, that is:

- the matching Scheduled Procedure Step, the Requested Procedure to which the Scheduled Procedure Step contributes, the Imaging Service Request in which the associated Requested Procedure is ordered, any associated Visit, and the Patient who is to be the subject of the Procedure.

Therefore, for a given C-FIND request, a given Scheduled Procedure Step will appear in only one of the resulting C-FIND responses. Obviously, information about the Requested Procedure, Imaging Service Request, Visit and Patient may be mentioned in several of these C-FIND responses.

The Modality Worklist Information Model is represented by the Entity Relationship diagram shown in figure Section K.6 -1.

### Note

The entities appearing in messages related to the Modality Worklist SOP Class are required to comply to the Modality Worklist model. However, DICOM does not define the internal structure of the database.

The entry point of the Modality Worklist is the Scheduled Procedure Step entity.

The Attributes of a Scheduled Procedure Step Worklist can be found in the following Modules in PS3.3.

- Patient Relationship Module

- Patient Identification Module

- Patient Demographic Module

- Patient Medical Module

- Visit Relationship Module

- Visit Identification Module

- Visit Status Module

- Visit Admission Module

- Scheduled Procedure Step Module

- Requested Procedure Module

- Imaging Service Request Module

Figure K.6-1. Modality Worklist Information Model E/R Diagram

##### K.6.1.2.2 Modality Worklist Attributes

Table K.6-1 defines the Attributes of the Modality Worklist Information Model:

Table K.6-1. Attributes for the Modality Worklist Information Model

Description / Module | Tag | Matching Key Type | Return Key Type | Remark / Matching Type
--- | --- | --- | --- | ---
Scheduled Procedure Step
Scheduled Procedure Step Sequence | (0040,0100) | R | 1 | The Attributes of the Scheduled Procedure Step shall only be retrieved with Sequence Matching. The Scheduled Procedure Step Sequence shall contain only a single Item.
>Scheduled Station AE Title | (0040,0001) | R | 1 | Scheduled Station AE Title shall be retrieved with Single Value Matching only.
>Scheduled Procedure Step Start Date | (0040,0002) | R | 1 | Scheduled Step Start Date shall be retrieved with Single Value Matching or Range Matching. See remark under Scheduled Procedure Step Start Time (0040,0003).
>Scheduled Procedure Step Start Time | (0040,0003) | R | 1 | Scheduled Step Start Time shall be retrieved with Single Value Matching or Range Matching. Scheduled Step Start Date and Scheduled Step Start Time are subject to Range Matching. If both keys are specified for Range Matching, e.g., the date range July 5 to July 7 and the time range 10am to 6pm specifies the time period starting on July 5, 10am until July 7, 6pm. ### Note If the Information System does not provide scheduling for individual Procedure Steps, it may use the closest scheduling information it possesses (e.g., Procedures are subject to scheduling instead of Procedure Steps).
>Modality | (0008,0060) | R | 1 | The Modality shall be retrieved with Single Value Matching.
>Scheduled Performing Physician's Name | (0040,0006) | R | 2 | Scheduled Performing Physician's Name shall be retrieved with Single Value Matching or Wild Card Matching.
>Scheduled Procedure Step Description | (0040,0007) | O | 1C | Either the Scheduled Procedure Step Description (0040,0007) or the Scheduled Protocol Code Sequence (0040,0008) or both shall be supported by the SCP.
>Scheduled Station Name | (0040,0010) | O | 2 |
>Scheduled Procedure Step Location | (0040,0011) | O | 2 |
>Referenced Defined Protocol Sequence | (0018,990C) | O | 3 |
>>Referenced SOP Class UID | (0008,1150) | O | 1 |
>>Referenced SOP Instance UID | (0008,1155) | O | 1 |
>Referenced Performed Protocol Sequence | (0018,990D) | O | 3 |
>>Referenced SOP Class UID | (0008,1150) | O | 1 |
>>Referenced SOP Instance UID | (0008,1155) | O | 1 |
>Scheduled Protocol Code Sequence | (0040,0008) | O | 1C | Either the Scheduled Procedure Step Description (0040,0007) or the Scheduled Protocol Code Sequence (0040,0008) or both shall be supported by the SCP. The Scheduled Protocol Code Sequence contains one or more Items.
>>Include Table 8-2a “Enhanced Coded Entry Macro with Optional Matching Key Support and Optional Meaning”
>>Protocol Context Sequence | (0040,0440) | - | 3 | The Protocol Context Sequence and its Items shall not be used for matching
>>>Value Type | (0040,A040) | - | 1 |
>>>Concept Name Code Sequence | (0040,A043) | - | 1 |
>>>>Include Table 8-3a “Enhanced SCU/SCP Coded Entry Macro with no SCU Support and no Matching Key Support”
>>>DateTime | (0040,A120) | - | 1C | Required if Value Type (0040,A040) is DATETIME.
>>>Person Name | (0040,A123) | - | 1C | Required if Value Type (0040,A040) is PNAME.
>>>Text Value | (0040,A160) | - | 1C | Required if Value Type (0040,A040) is TEXT.
>>>Concept Code Sequence | (0040,A168) | - | 1C | Required if Value Type (0040,A040) is CODE.
>>>>Include Table 8-3a “Enhanced SCU/SCP Coded Entry Macro with no SCU Support and no Matching Key Support”
>>>Numeric Value | (0040,A30A) | - | 1C | Required if Value Type (0040,A040) is NUMERIC.
>>>Measurement Units Code Sequence | (0040,08EA) | - | 1C | Required if Value Type (0040,A040) is NUMERIC.
>>>>Include Table 8-3a “Enhanced SCU/SCP Coded Entry Macro with no SCU Support and no Matching Key Support”
>>>All other Attributes of the Protocol Context Sequence |  | - | 3 |
>Pre-Medication | (0040,0012) | O | 2C | Required if Pre-Medication is to be applied to that Scheduled Procedure Step.
>Scheduled Procedure Step ID | (0040,0009) | O | 1 |
>Requested Contrast Agent | (0032,1070) | O | 2C | Required if Contrast Media is to be applied to that Scheduled Procedure Step.
>Scheduled Procedure Step Status | (0040,0020) | O | 3 |
>All other Attributes of the Scheduled Procedure Step Sequence |  | O | 3 |
Scheduled Specimen Sequence | (0040,0500) | O | 3 | One or more Items may be returned in this Sequence.
>Container Identifier | (0040,0512) | O | 1 |
>Container Type Code Sequence | (0040,0518) | - | 2 | Zero or one Item shall be returned in this Sequence.
>>Include Table 8-3a “Enhanced SCU/SCP Coded Entry Macro with no SCU Support and no Matching Key Support”
>Specimen Description Sequence | (0040,0560) | O | 1 | One or more Items shall be returned in this Sequence.
>>Specimen Identifier | (0040,0551) | O | 1 |
>>Specimen UID | (0040,0554) | O | 1 |
>>All other Attributes of the Specimen Description Sequence |  | O | 3 | Specimen Preparation Sequence (0040,0610), if present, describes preparation steps already performed, not scheduled procedure steps
>All other Attributes of the Scheduled Specimen Sequence |  | O | 3 |
Barcode Value | (2200,0005) | O | 3 | This may be the same as Container Identifier (0040,0512).
Requested Procedure
Requested Procedure ID | (0040,1001) | O | 1 |
Requested Procedure Description | (0032,1060) | O | 1C | The Requested Procedure Description (0032,1060) or the Requested Procedure Code Sequence (0032,1064) or both shall be supported by the SCP.
Requested Procedure Code Sequence | (0032,1064) | O | 1C | The Requested Procedure Description (0032,1060) or the Requested Procedure Code Sequence (0032,1064) or both shall be supported by the SCP. The Requested Procedure Code Sequence shall contain only a single Item.
>Include Table 8-2a “Enhanced Coded Entry Macro with Optional Matching Key Support and Optional Meaning”
Study Instance UID | (0020,000D) | O | 1 |
Study Date | (0008,0020) | O | 3 | See note 5.
Study Time | (0008,0030) | O | 3 | See note 5.
Referenced Study Sequence | (0008,1110) | O | 2 |
>Referenced SOP Class UID | (0008,1150) | O | 1 |
>Referenced SOP Instance UID | (0008,1155) | O | 1 |
Requested Procedure Priority | (0040,1003) | O | 2 |
Patient Transport Arrangements | (0040,1004) | O | 2 |
All other Attributes of the Requested Procedure Module |  | O | 3 |
Imaging Service Request
Accession Number | (0008,0050) | O | 2 |
Issuer of Accession Number Sequence | (0008,0051) | O | 3 |
Requesting Physician | (0032,1032) | O | 2 |
Referring Physician's Name | (0008,0090) | O | 2 |
All other Attributes of the Imaging Service Request Module |  | O | 3 |
Visit Identification
Admission ID | (0038,0010) | O | 2 |
Issuer of Admission ID Sequence | (0038,0014) | O | 3 |
All other Attributes of the Visit Identification Module |  | O | 3 |
Visit Status
Current Patient Location | (0038,0300) | O | 2 |
All other Attributes of the Visit Status Module |  | O | 3 |
Visit Relationship
Referenced Patient Sequence | (0008,1120) | O | 2 |
>Referenced SOP Class UID | (0008,1150) | O | 1 |
>Referenced SOP Instance UID | (0008,1155) | O | 1 |
All other Attributes of the Visit Relationship Module except those explicitly included in this table (see Note 3) |  | O | 3 |
Visit Admission
All Attributes from the Visit Admission Module |  | O | 3 |
Patient Relationship
All Attributes from the Patient Relationship Module except those explicitly included in this table (see Note 3) |  | O | 3 |
Patient Identification
Patient's Name | (0010,0010) | R | 1 | Patient Name shall be retrieved with Single Value Matching or Wild Card Matching.
Patient ID | (0010,0020) | R | 1 | Patient ID shall be retrieved with Single Value Matching.
Issuer of Patient ID | (0010,0021) | O | 3 |
Issuer of Patient ID Qualifiers Sequence | (0010,0024) | O | 3 |
Other Patient IDs Sequence | (0010,1002) | O | 3 |
All other Attributes of the Patient Identification Module |  | O | 3 |
Patient Demographic
Patient's Birth Date | (0010,0030) | O | 2 |
Patient's Sex | (0010,0040) | O | 2 |
Patient's Primary Language Code Sequence | (0010,0101) | O | 3 | The languages that can be used to communicate with the patient. If returned, the Patient's Primary Language Code Sequence shall contain one or more Items. The items are ordered by preference (most preferred language to least preferred language).
>Include Table 8-4a “Enhanced Coded Entry Macro with Optional Matching Key Support and Mandatory Meaning”
>Patient's Primary Language Modifier Code Sequence | (0010,0102) | O | 3 | A modifier for a Patient's Primary Language. Can be used to specify a national language variant. If returned, the Patient's Primary Language Modifier Code Sequence shall contain only a single Item.
>>Include Table 8-4a “Enhanced Coded Entry Macro with Optional Matching Key Support and Mandatory Meaning”
Patient's Weight | (0010,1030) | O | 2 |
Patient's Size | (0010,1020) | O | 3 |
Confidentiality constraint on patient data | (0040,3001) | O | 2 |
All other Attributes of the Patient Demographic Module |  | O | 3 |
Patient Medical
Patient State | (0038,0500) | O | 2 |
Pregnancy Status | (0010,21C0) | O | 2 |
Medical Alerts | (0010,2000) | O | 2 |
Allergies | (0010,2110) | O | 2 |
Special Needs | (0038,0050) | O | 2 |
Pertinent Documents Sequence | (0038,0100) | O | 3 | Pertinent Documents Sequence shall be retrieved with Universal Matching only
>Referenced SOP Class UID | (0008,1150) | - | 1 |
>Referenced SOP Instance UID | (0008,1155) | - | 1 |
>Purpose of Reference Code Sequence | (0040,A170) | - | 2 |
>>Include Table 8-3a “Enhanced SCU/SCP Coded Entry Macro with no SCU Support and no Matching Key Support”
>Document Title | (0042,0010) | - | 2 |
All other Attributes of the Patient Medical Module |  | O | 3 |

### Note

1. Just like Series and Image Entities specified in the Query/Retrieve Service Class either an SCU or an SCP may support optional Matching Key Attributes and/or Type 3 Return Key Attributes that are not included in the Worklist Information Model (i.e., Standard or Private Attributes). This is considered a Standard Extended SOP Class (see PS3.2).

2. Each Module contains a Comment Attribute. This may be used to transmit non-structured information, which may be displayed to the operator of the Modality.

3. The reason for this exclusion is to assure that the Attributes that may be present in multiple Modules are included only once with the meaning pertaining to only one Module (for example, Referenced Study Sequence (0008,1110) shall be included once with the meaning as defined in the Requested Procedure Module).

4. The use of Specific Character Set is discussed in section Section K.4.1.1.3.1 and Section K.4.1.1.3.2.

5. The values of Study Date (0008,0020) and Study Time (0008,0030) may be provided in order to achieve consistency of Study level Attributes in composite instances generated in multiple performed procedure steps on different devices, and the worklist values may be updated by the SCP based on information received from Modality Performed Procedure Steps or by examining the composite instances generated.

The Attributes in Table K.6-1a are not part of the Worklist Information Model; their inclusion in the C-FIND request and response identifier are governed by rules in sections Section K.4.1.1.3.1 and Section K.4.1.1.3.2, respectively.

Table K.6-1a. Attributes for the Modality Worklist C-FIND Identifier

Attribute Name | Tag | Request Identifier | Response Identifier | Remark Type
--- | --- | --- | --- | ---
Specific Character Set | (0008,0005) | 1C | 1C | This Attribute is required if expanded or replacement character sets are used. See Section C.2.2.2 and Section K.4.1.1.3
Timezone Offset From UTC | (0008,0201) | 1C | 1C | This Attribute is required if times are to be interpreted explicitly in the designated local timezone. See Section C.2.2.2 and Section K.4.1.1.3
HL7 Structured Document Reference Sequence | (0040,A390) | - | 1C | One or more Items may be included in this sequence. Required if HL7 Structured Documents are referenced within the Identifier. See Section K.4.1.1.3
>Referenced SOP Class UID | (0008,1150) | - | 1 |
>Referenced SOP Instance UID | (0008,1155) | - | 1 |
>HL7 Instance Identifier | (0040,E001) | - | 1 |
>Retrieve URI | (0040,E010) | - | 3 |

#### K.6.1.3 Conformance Requirements

An implementation may conform to the Modality Worklist SOP Class as an SCU or an SCP. The Conformance Statement shall be in the format defined in PS3.2.

##### K.6.1.3.1 SCU Conformance

An implementation that conforms to the Modality Worklist SOP Class shall support queries against the Worklist Information Model described in Section K.6.1.2 of this Annex using the baseline C-FIND SCU Behavior described in Section K.4.1.2 of this Part.

An implementation that conforms to the Modality Worklist SOP Class as an SCU shall state in its Conformance Statement whether it requests matching on Optional Matching Key Attributes. If it requests Type 3 Return Key Attributes, then it shall list these Optional Return Key Attributes. It shall identify any Templates it supports for the Protocol Context Sequence.

An implementation that conforms to the Modality Worklist SOP Class as an SCU shall state in its Conformance Statement whether or not it supports extended negotiation of fuzzy semantic matching of person names.

An implementation that conforms to the Modality Worklist SOP Class as an SCU shall state in its Conformance Statement how it makes use of Specific Character Set (0008,0005) and Timezone Offset From UTC (0008,0201) when encoding queries and interpreting responses.

##### K.6.1.3.2 SCP Conformance

An implementation that conforms to the Modality Worklist SOP Class shall support queries against the Worklist Information Model described in Section K.6.1.2 of this Annex using the C-FIND SCP Behavior described in Section K.4.1.3 of this Part.

An implementation that conforms to the Modality Worklist SOP Class as an SCP shall state in its Conformance Statement whether it supports matching on Optional Matching Key Attributes. If it supports Type 3 Return Key Attributes, then it shall list the Optional Return Key Attributes that it supports. It shall identify any Templates it supports for the Protocol Context Sequence.

An implementation that conforms to the Modality Worklist SOP Class as an SCP shall state in its Conformance Statement whether it supports case-insensitive matching for PN VR Attributes and list Attributes for which this applies.

An implementation that conforms to the Modality Worklist SOP Class as an SCP shall state in its Conformance Statement whether or not it supports extended negotiation of fuzzy semantic matching of person names. If fuzzy semantic matching of person names is supported, then the mechanism for fuzzy semantic matching shall be specified.

An implementation that conforms to the Modality Worklist SOP Class as an SCP shall state in its Conformance Statement how it makes use of Specific Character Set (0008,0005) and Timezone Offset From UTC (0008,0201) when interpreting queries, performing matching and encoding responses.

#### K.6.1.4 SOP Class

The Modality Worklist SOP Class in the Basic Worklist Service Class identifies the Modality Worklist Information Model, and the DIMSE-C operations supported. The following Standard SOP Class is identified:

Table K.6.1.4-1. Modality Worklist SOP Class

SOP Class Name | SOP Class UID
--- | ---
Modality Worklist Information Model - FIND | 1.2.840.10008.5.1.4.31

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DICOM PS3.4 2020a - Service Class Specifications