DICOM PS3.17 2021e - Explanatory Information

J.4 One MPPS Is Created in Response to Two Or More Requested Procedures

In the MPPS SOP Instance, all the specific Attributes of a Scheduled Procedure Step or Steps are included in the Scheduled Step Attributes Sequence. In the Image SOP Instances, these Attributes may be included in the Request Attributes Sequence. This is an optional Sequence in order not to change the definition of existing SOP Classes by adding new required Attributes or changing the meaning of existing Attributes.

Both Sequences may have more than one Item if more than one Requested Procedure results in a single Performed Procedure Step.

Because of the definitions of existing Attributes in existing Image SOP Classes, the following solutions are a compromise. The first one chooses or creates a value for the single valued Attributes Study Instance UID and Accession Number. The second one completely replicates the Image data with different values for the Attributes Study Instance UID and Accession Number.

J.4.1 Choose Or Create A Value For Study Instance UID and Accession Number

The modality may:

  • In the Image SOP Instances:

    • create a Request Attributes Sequence containing two or more Items each containing the following Attributes:

      • Requested Procedure ID

      • Scheduled Procedure Step ID

      • Scheduled Procedure Step Description

      • Scheduled Protocol Code Sequence

    • create a Referenced Study Sequence containing two or more Items sufficient to contain the Study SOP Instance UID values from the Modality Worklist for both Requested Procedures

    • select one value from the Modality Worklist or generate a new value for:

      • Study Instance UID

    • select one value from the Modality Worklist or generate a new value or assign an empty value for:

      • Accession Number

  • In the MPPS SOP Instance:

    • create a Scheduled Step Attributes Sequence containing two or more Items each containing the following Attributes:

      • Study Instance UID

      • Referenced Study Sequence

      • Accession Number

      • Requested Procedure ID

      • Scheduled Procedure Step ID

      • Scheduled Procedure Step Description

      • Scheduled Protocol Code Sequence

    • include the following Attribute value that may be generated during image acquisition, if supported:

      • Procedure Code Sequence

  • In both the Image SOP Instances and the MPPS SOP Instance

    • create a Performed Procedure Step ID

    • include the following Attribute values that may be generated during image acquisition, if supported:

      • Performed Procedure Step Start Date

      • Performed Procedure Step Start Time

      • Performed Procedure Step Description

      • Study ID

DICOM PS3.17 2021e - Explanatory Information