sending 2 object instance at a time using cstore

[RRaut]

Hi,

1> I m confused regarding the no. of request we can send at a time to scp.

Can we send 2 cstore requests at a time in only one association.

or

two different associations are required for each object to send.

2>Can we send 2 patientqueryrootlevel cfind request at a time?
or we have to wait till the response for the first request is received by scu for sending second request.

please help..

[Michael Onken]

Hi,

please post only any DCMTK related questions to this forum.

ad 1)
You can send as many images on one associaton as you like. You have to be sure during association negotiation that all SOP Classes and Transfersyntax combinations (=Presentation Contexts) you will ever send on the association are all negotiated. Note that usually you have to wait for a response after sending an image before sending the next one. But DICOM does not define when or that you have to end an association at all.

ad 2) As stated in 1), usually you have to wait for a response before sending the next message. This is called synchronous mode in DICOM. There actually is a asynchronous mode in DICOM which is rarely implemented. Support of that mode must be negotiated during association negotiation, too. See Annex D in part 7 of the standard, especially D.3.3.3 ASYNCHRONOUS OPERATIONS (AND SUB-OPERATIONS) WINDOW NEGOTIATION. DCMTK does not fully support asynchronous operation (but has some parts implemented, as far as I remember... )
This asynchronous mode could be used not only for CFIND but for all DICOM associations, e. g. also for storage (to come back to your first question...)

Regards,
Michael

[tpalagyi]

"DCMTK does not fully support asynchronous operation (but has some parts implemented, as far as I remember... ) "
Any change around asynchronous operations?
I know it is hardly implemented by vendors, but could be useful to fight network latency.