DICOM PS3.4 2024b - Service Class Specifications

Z.4.2.3 C-GET SCP and C-STORE SCU Behavior

Z. Baseline Behavior of SCP

An SCP conveys the following semantics with a C-GET response:

  • The SCP shall identify a set of Entities at the level of the transfer based upon the values in the Unique Keys in the Identifier of the C-GET request.

  • The SCP shall initiate C-STORE sub-operations for the identified SOP Instances, but shall not include in this C-STORE sub-operation the Attributes described in Section Z.1.3. The SCP of the Query/Retrieve Service Class shall serve as an SCU of the Storage Service Class.

  • Apart from the Attributes listed in Section Z.1.3, the SOP Instance sent via the C-STORE sub-operation shall be unchanged, and no corresponding changes to other Attributes shall be made.


In particular, the Study, Series and SOP Instance UIDs and SOP Class UID will not be altered.

  • The SCP shall initiate C-STORE sub-operations over the same Association for all SOP Instances specified in the C-GET request.

  • A sub-operation is considered a Failure if the SCP is unable to initiate a C-STORE sub-operation because the Query/Retrieve SCU did not offer an appropriate presentation context for a given stored SOP Instance.

  • Optionally, the SCP may generate responses to the C-GET with status equal to Pending during the processing of the C-STORE sub-operations. These responses shall indicate the number of Remaining, Completed, Failure, and Warning C-STORE sub-operations.

  • When the number of Remaining sub-operations reaches zero, the SCP shall generate a final response with a status equal to Success, Warning or Failed. The status contained in the C-GET response shall contain:

    • Success if all sub-operations were successfully completed

    • Failure if all sub-operations were unsuccessful

    • Warning in all other cases.

  • The SCP may receive a C-CANCEL-GET request at any time during the processing of the C-GET request. The SCP shall interrupt all C-STORE sub-operation processing and return a status of Canceled in the C-GET response. The C-GET response with a status of Canceled shall contain the number of Completed, Failed, and Warning C-STORE sub-operations. If present, the Remaining sub-operations count shall contain the number of C-STORE sub-operations that were not initiated due to the C-CANCEL-GET request.

  • If the SCP manages images in multiple alternate encodings (see Section C., only one of the alternate encodings of an image shall be used as the existing SOP Instance from which frames are to be extracted.

DICOM PS3.4 2024b - Service Class Specifications