By the endIdentify the payload and peer roles in a C-STORE operation.
Follow the request and the response
C-STORE is the DIMSE-C service used to store a composite SOP Instance on a peer. The Storage SCU sends the request and the instance. The Storage SCP receives the request, processes the instance, and returns a response. Reading the exchange in that order prevents the response from being mistaken for a second transfer.
C-STORE request and response
The Storage SCU sends C-STORE-RQ and a composite SOP Instance to the Storage SCP. The Storage SCP sends C-STORE-RSP status back to the Storage SCU.
Worked example
A CT series arrives one instance at a time
A CT acquisition produces many image instances. For each instance, the modality invokes C-STORE toward the archive and receives a response for that operation.
1
Identify the unit
The C-STORE operation concerns one composite SOP Instance. A study or series can therefore involve many C-STORE operations.
2
Follow the request
The Storage SCU sends C-STORE-RQ with the instance data to the Storage SCP.
3
Follow the response
The Storage SCP returns C-STORE-RSP with the status for that operation. Success or Warning cannot be returned until the full C-STORE indication has been received.
Result: A successful response belongs to the instance and operation that it answers. When a series is incomplete, inspect the responses across the whole group instead of relying on one successful instance.
Storage and Query/Retrieve are separate service claims
An archive may support both, but one capability does not prove the other. Read the conformance statement by SOP Class and role.
C-STORE
Transfers a composite SOP Instance
Uses Storage SCU and SCP roles
Returns a status for the store operation
C-FIND
Matches requested attributes
Returns matching Identifiers in Pending responses
May be used by a Query/Retrieve FIND SOP Class
Try it
Account for a partial series
A modality sends 120 image instances. The first 119 C-STORE operations succeed, and the final operation fails. Can the successful response for instance 119 be used as the result for instance 120?
Hint: Match each response to the operation it answers.
No. Each C-STORE response reports the outcome of its corresponding operation. The final failed operation must be handled as a failure even though earlier instances in the same series were stored successfully.
02 / Questions
Answer 4 questions
Choose an answer. The explanation appears after you submit.
Check 1 of 4recall · easy
What does the C-STORE service place on a peer DIMSE Service User?
C-STORE is used to store a composite SOP Instance on a peer DIMSE Service User. A routing table is network configuration, not the payload of a C-STORE operation.
Check 2 of 4scenario · medium
A PACS accepts CT images with C-STORE. Which additional capability can be concluded from that fact alone?
Storage support is a conformance claim for particular Storage SOP Classes and roles. Query/Retrieve support is a separate claim, so accepting C-STORE does not establish it.
Check 3 of 4scenario · medium
Which evidence reports the outcome of a specific C-STORE operation?
C-STORE is a confirmed DIMSE service. Its response carries the status of the corresponding storage operation. The other options do not state this source-defined rule.
Check 4 of 4recall · medium
In a DICOM Storage operation, what does C-STORE transfer to the peer Application Entity?
The Storage Service Class transfers Composite SOP Instances between peer DICOM Application Entities, and each C-STORE request names the SOP Class and the SOP Instance being stored. The network connection, presentation-context proposal, and C-ECHO message support other parts of communication but are not the stored information object.
03 / Recall
Answer without looking back
Describe C-STORE in one sentence using the terms composite SOP Instance, SCU, and SCP.
A Storage SCU uses C-STORE to request that a peer Storage SCP store a composite SOP Instance.
An imaging modality that produces cross-sectional images using X-rays and computational reconstruction.
SOP ClassService-Object Pair Class
For DIMSE services, the union of an Information Object Definition and a set of DIMSE services: a Composite IOD with DIMSE-C services, or a Normalized IOD with DIMSE-N services.
SCUService Class User
The role played by a DICOM Application Entity that invokes operations on a specific Association. When its peer invokes a notification, the SCU is the side that receives it and acts on it.
SCPService Class Provider
The role played by a DICOM Application Entity that performs operations and invokes notifications on a specific Association. It performs the operations its peer asks for, and it sends notifications about events to that peer.
DIMSE-CDICOM Message Service Element - Composite
The subset of DIMSE services that operates on Composite SOP Instances.
C-STORE
The DIMSE-C service used to store a composite SOP Instance on a peer.
C-FIND
The DIMSE-C service used to match attributes against attributes maintained by a peer.
composite SOP Instance
One populated occurrence of a composite information object class, such as a particular CT Image instance.
Pending
A C-FIND response status that indicates matching is still in progress and carries a matching Identifier.