The Procedural Event Logging SOP Class allows SCUs to report to an SCP the events that are to be recorded in a Procedure Log SOP Instance, as described in PS3.3. This allows multiple devices participating in a Study to cooperatively construct a log of events that occur during that Study.
The multiple procedural events reported through this SOP Class are related by Patient ID, Study Instance UID, Study ID, and/or Performed Location. The mechanism by which multiple devices obtain these shared identifiers is not defined by this SOP Class.
The Modality Worklist or UPS SOP Classes may be used for this purpose. For simple devices that cannot support worklist SOP classes, the SCP may be able to use Performed Location, or the SCU AE Title, to relate the use of the device to a particular procedure.
The SCP may also provide for recording events for which the SCU does not provide identifiers for matching. The mechanism by which the SCP determines the association of such an unidentified event with the log for a specific procedure is not defined by this SOP Class.
The network address and/or AE Title of the SCU may be used to identify the device as a participant in a particular procedure.
The DIMSE-N Services applicable to the Procedural Event Logging SOP Class are shown in Table P.2-1.
The DIMSE-N Services and Protocol are specified in PS3.7.
The DICOM AEs that claim conformance to this SOP Class as an SCU shall invoke the N-ACTION request. The DICOM AEs that claim conformance to this SOP Class as an SCP shall support the N-ACTION request.
The DICOM AEs that claim conformance to this SOP Class as an SCU and/or an SCP shall support the Action Type and Action Information in the N-ACTION-RQ as specified in Table P.2-2.
Table P.2-2. Procedural Event Logging Action Information
|
Action Type Name |
Action Type ID |
Attribute |
Tag |
Requirement Type SCU/SCP |
|---|---|---|---|---|
|
Record Procedural Event |
1 |
Specific Character Set |
(0008,0005) |
1C/1C (Required if an extended or replacement character set is used) |
|
Patient ID |
(0010,0020) |
2/2 |
||
|
Study Instance UID |
(0020,000D) |
2/2 |
||
|
Study ID |
(0020,0010) |
2/2 |
||
|
Synchronization Frame of Reference UID |
(0020,0200) |
2/2 |
||
|
Performed Location |
(0040,0243) |
2/2 |
||
|
All other Attributes of the SR Document Content Module (PS3.3) using Procedure Log IOD Content Constraints |
The SCU may provide Patient ID (0010,0020), Study Instance UID (0020,000D), Study ID (0020,0010), and/or Performed Location (0040,0243) Attributes to allow the SCP to match the N-ACTION with a Study for which a procedure log is being created.
The Synchronization Frame of Reference UID (0020,0200) Attribute identifies the temporal frame of reference for the Observation DateTime (0040,A032) Attributes in the Procedural Event record. If the Observation DateTime Attribute values are not synchronized in an identifiable Frame of Reference, the Attribute shall be zero length.
The Procedural Event record shall be conveyed in a (top level) Content Item, and subsidiary Content Items, as specified by the SR Document Content Module definition in PS3.3.
The top level and subsidiary Content Items shall be constructed in accordance with the Procedure Log IOD Content Constraints of PS3.3.
These constraints specify use of BTID 3001 Procedure Log defined in PS3.16, and specific particular use of the Observation DateTime (0040,A032) Attributes.
TID 3001 requires the explicit identification of the Observer Context of the top level CONTAINER through TID 1002.
There may be multiple events (subsidiary Content Items) included in a single N-ACTION-RQ message.
The SCU shall request logging of events that occur during a Study, using the N-ACTION request primitive.
The SCU shall receive N-ACTION responses. The actions taken upon a response status of Failure, or upon non-response of the SCP, are implementation dependent.
The SCP shall manage the creation of SOP Instances of the Procedure Log Storage Service. It shall receive, via the N-ACTION request primitive, requests for logging of events that occur during a Study. The SCP shall (consonant with application dependent constraints) incorporate those event records into a Procedure Log SOP Instance for the specified Study.
The SCP shall return, via the N-ACTION response primitive, the N-ACTION Response Status Code applicable to the associated action request.
The Service Class specific status values defined for the N-ACTION Service are specified in Table P.2-3. See PS3.7 for additional general response status codes.
Table P.2-3. Response Status
|
Service Status |
Response Status Code |
Further Meaning |
|---|---|---|
|
Success |
0000 |
|
|
Warning |
B101 |
Specified Synchronization Frame of Reference UID does not match SCP Synchronization Frame of Reference |
|
Warning |
B102 |
Study Instance UID coercion; Event logged under a different Study Instance UID |
|
Warning |
B104 |
IDs inconsistent in matching a current study; Event logged |
|
Failure |
C101 |
Procedural Logging not available for specified Study Instance UID |
|
Failure |
C102 |
Event Information does not match Template |
|
Failure |
C103 |
Cannot match event to a current study |
|
Failure |
C104 |
IDs inconsistent in matching a current study; Event not logged |
With any response status indicating Success or Warning, the identifiers of the study into which the event has been logged shall be returned in the N-ACTION-RSP Action Reply as specified in Table P.2-4.
Table P.2-4. Procedural Event Logging Action Reply
|
Action Type Name |
Action Type ID |
Attribute |
Tag |
Requirement Type SCU/SCP |
|---|---|---|---|---|
|
Record Procedural Event |
1 |
Study Instance UID |
(0020,000D) |
3/1 |
|
Patient ID |
(0010,0020) |
3/1 |
The Procedural Event Logging SOP Class shall be uniquely identified by the Procedural Event Logging SOP Class UID, which shall have the value "1.2.840.10008.1.40".
The well-known UID of the Procedural Event Logging SOP Instance shall have the value "1.2.840.10008.1.40.1".
The DICOM AE's Conformance Statement shall be formatted as defined in PS3.2.
The SCU shall document in its Conformance Statement the behavior and actions that cause the SCU to generate an N-ACTION primitive (Procedural Event Notification). It shall specify the Template used for constructing the Event Information, and the Coding Schemes used for coded entries in the Event Information.
The SCU shall document the identifiers it sends for matching purposes, and how it obtains those Attributes (e.g., through a Modality Worklist query, manual entry, etc.).
The SCU shall document the behavior and actions performed when a success, warning, or failure status is received.
The SCU shall document the mechanisms used for establishing time synchronization and specifying the Synchronization Frame of Reference UID.
The SCP shall document in its Conformance Statement how it uses the identifiers it receives for matching the N-ACTION (Procedural Event Notification) to a specific procedure.
The SCP shall document the behavior and actions that cause the SCP to generate a success, warning, or failure status for a received N-ACTION.
The SCP shall document the behavior and actions that cause the SCP to generate a Procedure Log SOP Instance including the received Event Information.
The SCP shall document how it assigns the value of the Observation Datetime (0040,A032) Attribute when the SCU-provided Synchronization Frame of Reference UID is absent, or differs from that of the SCP.