Series Level association

[gnchen]

Hi!

In current storescp, you have image level association and some study level association options there. But how about Series Level association? What is the best way to know when a series have been transferred?? Is there a Presentation context like this in DICOM standard?

Gen

[Marco Eichelberg]

Actually there is no way in the DICOM C-STORE protocol to know that a complete series or a complete study has been transferred. The "study level" options for executing certain commands or sorting images are based on the assumption that images are sent in strict order, series for series and study for study, patient for patient. This is not a requirement of the DICOM standard - modalities might send images in any order or might split a transmission of one series or one study over several associations. In all of these cases, the study level options will be executed too often or will generate too many subdirectories. However, in most cases things just work so we believed it would be useful to make such options available. Similar "per-series" options would be trivial to implement, but so far there has not been any need for this.

[gnchen]

Thanks! Macro. So, does that mean I should use dcmqrscp to store all images first. Then, using movescu to query and retrieve for a particular series I need. But this still did not solve the transferring completion problem. Any suggestion on this except implementing our own per-series logic? I really like to be just a user on those existing binaries...

Thanks!


Gen

[Marco Eichelberg]

The only reliably way of knowing how many objects are in one particular series is to use the content of the MPPS (Modality Performed Procedure Step) message that some modalities can send to the RIS or to the PACS. This message (when in COMPLETED status) will provide a list of all objects belonging to one series. However, many modalities do not support this service and DCMTK does not have an implementation for it as well. Other than that, you can just expect that once you have not received any new objects for a specific series in a while, it is most likely complete. But there's no guarantee (which was one of the reaons why the DICOM committee invented MPPS).

[gnchen]

Thanks. Does MR modality support MPPS? Is it well-suported in all PACS system? Or just another standard no one really pay attention too??

[Marco Eichelberg]

Does MR modality support MPPS?

This depends on the manufacturer, model and software version. You need to consult the conformance statement to know this.

Is it well-suported in all PACS system?

No. Some PACSes do, some RISes do, but not all of them - and in the case of a PACS not all of them actually need to, depending on their storage architecture. The IHE Technical Framework, however, mandates that both RIS and PACS systems must be able to receive MPPS messages, but does not specify to what degree the messages need to be processed.

[gnchen]

Thanks! Marco,

Looks like adding some series options there is my best bet. Thanks!!

Gen