DICOM association clarification

[harithacha...@gmail.com]

Hi, 

I have a small doubt, 

When a scu is sending association request in the following order :

Modality worklist information model -FIND

Modality performed procedure step SOP class

Verification SOP class

can dcm4che SCP send back acknowledgment in the reverse order.i.e

Verification SOP class

Modality performed procedure step SOP class

Modality worklist information model -FIND

can the order be changed in dcm4che?

do we have that provision?

i tried to go through the code i could not do it.

Would be very helpful if i get any help regarding this.

Thanks,

Haritha C Mouli

[Gunter Zeilinger]

Depends if the  Association-requester (MWL C-FIND-SCU/C-ECHO SCU) requested support of Asynchronous Operations  in the A-ASSOCIATE request, and if the Association-acceptor (MWL C-FIND SCP/C-ECHO SCP) accepted support of Asynchronous Operations  in the A-ASSOCIATE response. If not, the Association-requester is not permitted to send the C-ECHO RQ before receiving the final C-FIND RSP.

s. DICOM PS 3.7, D.3.3.3 Asynchronous Operations (And Sub-Operations) Window Negotiation

[Gunter Zeilinger]

dcm4che's C-FIND SCP implementations send C-FIND responses in a different thread than the C-ECHO RSP - later is sent directly b the thread which read the C-ECHO RQ. So the order of the sending of the (final) C-FIND RSP and the  C-ECHO RSP is not deterministic..