About SCU and SCP

 

About SCU and SCP 1

About SCU and SCP Version 1.0

History Person  

Version Abdolreza

Testing Date 1.0

2007-03-16

 

About SCU and SCP 2

  A brief definition about what is SCU and what are SCP and what kind operation can be done on them: them : Roles: Service Class User (SCU) and Service Class Provider Perhaps no part of the DICOM terminology is more confusing than the terms Service Class User and Service Class Provider. If you will think of DICOM as a client/server model, think of  the SCU as the client and the SCP as the server. The SCU (or client) requests some service from the SCP (or server). In DICOM, however, the roles SCP and SCU refer to the specific service being provided at the time and not to the overall architecture. A DICOM entity commonly acts in several service class roles either as user or as provider, and often in both.  The SOP class defines the actions of the SCU and the SCP. Let’s examine briefly how the SCU and SCP interact in each service class.

Verification Service Class SCP/SCU Roles  The Verification Service Class is simply a means of determining whether a DICOM entity is active and can be reached on the network. The SCU requests this verification and the SCP, if  active, provides a response. No other data is exchanged.

Storage Service Class SCP/SCU Roles Each of the Storage SOP Classes handle only one particular image (or other object) type. The use of the term “Storage” is perhaps unfortunate. “Send” would perhaps be a better name. When the SCU requests that an image be stored, it is really only requesting that the SCP receive receiv e the image. The SCP does not guarantee any duration or safety of storage, but merely accepts the image from the sender. In real life, there usually is some duration of  storage implied, possibly even some archiving, but that is up to the manufacturer.

Query/Retrieve Service Class SCP/SCU Roles  The Query/Retrieve Service Class provides two distinct services: Find and move, hence the name Query/Retrieve. In the case of a find request, the SCU requests information (such as patient name, study ID, etc.) about images that the provider has available. The SCP then responds with any of the requested information that it has.

 

About SCU and SCP 3

In the case of a move request, the SCU is asking that certain images be moved from the SCP to some destination. Although it is typical that the SCU requests the images to be sent from the SCP back to the SCU (basic retrieve operation), operation), it is also com common mon for the SCU to request that the images be sent to a third entity. entity. Note that the move SCP must also be an SCU of the Storage Service Class to send the image to the destination.