F.10.2 Operations

The DICOM AEs that claim conformance to this SOP Class as an SCU shall invoke the N-ACTION operation. The DICOM AEs that claim conformance to this SOP Class as an SCP shall support the N-ACTION operation.

F.10.2.1 Modify General Purpose Scheduled Procedure Step Information Request

This operation allows an SCU to request the modification of Attribute Values of an instance of the General Purpose Scheduled Procedure Step SOP Class and provide information about a specific real-world General Purpose Scheduled Procedure Step that is under control of the SCP. This operation shall be invoked through the DIMSE N-ACTION Service.

F.10.2.1.1 Action Information

The Application Entity which claims conformance to this SOP Class as an SCU may choose to request the modification of a subset of the Attributes maintained by the SCP.

The DICOM AEs that claim conformance to this SOP Class as an SCU and/or an SCP shall support the Action Types and Action Information as specified in Table F.10.2-1.

Table F.10.2-1MODIFY GP-SPS INFORMATION REQUEST – ACTION INFORMATION

Action Type Name Action Type ID Attribute Tag Requirement Type SCU/SCP
Request GP-SPS Status Modification 1 General Purpose Scheduled Procedure Step Status (0040,4001) 1/1
Transaction UID (0008,1195) 1/1
Actual Human Performers Sequence (0040,4035) 3/1
>Human Performer Code Sequence (0040,4009) 1/1
>>Code Value (0008,0100) 1/1
>>Coding Scheme designator (0008,0102) 1/1
>>Code Meaning (0008,0104) 1/1
>Human Performer’s Name (0040,4037) 3/3
>Human Performer’s Organization (0040,4036) 3/3

F.10.2.1.2 Service Class User Behavior

The SCU shall specify in the Requested SOP Instance UID parameter of the N-ACTION request primitive the UID of the General Purpose Scheduled Procedure Step SOP Instance for which it wants to modify Action Information, as specified in Table F.10.2-1.

Note: In the usage described here, there is no explicit creation of a SOP Instance upon which an N-ACTION primitive may operate. Instead, the N-ACTION primitive operates upon a SOP Instance previously created by the SCP. The SCU will retrieve the value for the SOP Instance UID by means of the General Purpose Worklist C-FIND service.

The SCU shall specify the requested value for the Attribute “General Purpose Scheduled Procedure Step Status” (0040,4001) in the Action Information.

The encoding rules for General Purpose Scheduled Procedure Step Action Information are specified in the N-ACTION request primitive specification in PS 3.7

The SCU shall not send N-ACTION request primitives for a General Purpose Scheduled Procedure Step SOP Instance when the Attribute “General Purpose Scheduled Procedure Step Status” (0040,4001) of that SOP Instance is “COMPLETED” or “DISCONTINUED”.

The SCU shall supply a “Transaction UID” Attribute (0008,1195) to identify the Modify GP-SPS Information Request that requests a modification of the value of the Attribute “General Purpose Scheduled Procedure Step Status” (0040,4001) to “IN PROGRESS”. The same Transaction UID shall be used to request a modification of the status from “IN PROGRESS” to: “SUSPENDED”, “SCHEDULED”, “COMPLETED” or “DISCONTINUED”. Once the status has any other value than “IN PROGRESS” this Transaction UID shall no longer be used.

Note: This “Transaction UID” Attribute (0008,1195) is used to identify the single transition into the “IN PROGRESS” state, not the ownership of the General Purpose Procedure Step SOP Instance.

F.10.2.1.3 Service Class Provider Behavior

The N-ACTION operation allows the SCU to request that the SCP update selected Attribute values for a specific General Purpose Scheduled Procedure Step SOP Instance. This operation shall be invoked through the use of the DIMSE N-ACTION Service used in conjunction with the appropriate General Purpose Scheduled Procedure Step SOP Instance.

The SCP shall return, via the N-ACTION response primitive, the N-ACTION Response Status Code applicable to the associated request. Contingent on the N-ACTION Response Status, the SCP shall update the Referenced General Purpose Scheduled Procedure Step Attributes.

The SCP shall accept N-ACTION request primitives for a SOP Instance only if the value of the Attribute “General Purpose Scheduled Procedure Step Status” (0040,4001) of that SOP Instance is “SCHEDULED” or “SUSPENDED” or “IN PROGRESS”. If the General Purpose Scheduled Procedure Step Status attribute has a value of “COMPLETED” or “DISCONTINUED”, the SCP shall send the failure status code as specified in Section F.10.2.1.4.

When the value of the Attribute “General Purpose Scheduled Procedure Step Status” (0040,4001) of the SOP Instance is “IN PROGRESS”, the SCP shall accept N-ACTION request primitives only if the Transaction UID of the request primitive equals the Transaction UID of the request primitive which has successfully requested the modification of the value of this Attribute to “IN PROGRESS”. If another value is used, the SCP shall send the failure status code as specified in Section F.10.2.1.4.

F.10.2.1.4 Status Codes

The status values which are specific for this SOP Class are defined in Table F.10.2-2.

Table F.10.2-2 SOP CLASS STATUS VALUES

Status Meaning Code
Success The requested modification of the attribute value is performed 0000
Failure Refused because General Purpose Scheduled Procedure Step Object may no longer be updated A501
Refused because the wrong Transaction UID is used. A502
Refused because the General Purpose Scheduled Procedure Step SOP Instance is already in the “IN PROGRESS” state A503