The main DICOM services
The DICOM standard specifies several images-related services which are useful in the medical imaging workflow.
Here is a short list of the most frequently-used DICOM services:
- Verification service
- Storage service
- Storage Commitment service
- Query/Retrieve service
- Print service
- Modality Worklist service
- Modality Performed Procedure Step service
The DICOM standard describes and defines these services both at the semantic level (i.e., what each service has been designed for) and at the protocol level (i.e., which kind of information must be exchanged for each service and in which format).
Each DICOM service implies the communication between the following entities:
- A Service Class Provider (also known as SCP): the DICOM node providing the DICOM service itself. Normally, this is a server from the network communication point of view, although there are some notable exceptions to this rule (e.g., within the Storage Commitment service). A typical example of DICOM SCP is the PACS server, which for instance provides storage services to DICOM clients.
- A Service Class User (also known as SCU): the DICOM node using the DICOM service. Normally, this is a client from the network communication point of view, connecting to the SCP in order to use / consume the DICOM service. Examples of SCUs are modalities or workstations, which for instance use the storage services provided by a PACS server in order to send DICOM images to PACS server’s archive.