Relational Queries (C-Find)

[geke]

Hello,

I did not see the term relational queries anywhere (newsgroup or website). Can someone can give more details what sort of queries orthanc can handle.

I have seen that orthanc can handle relational queries (without an extended association request ) and usual hierarchical queries.

Does orthanc support standard conform relational queries. Does orthanc answer an extended association request where relational queries are ordered? I think this is the standard way how relational queries are used.

Greeting Gerd

[Sébastien Jodogne]

Hello,

I don't understand your question/goal.

You can query Orthanc either using the DICOM C-Find protocol, or using the REST API of Orthanc.

For the former (DICOM networking), please have a look at the "Understanding DICOM with Orthanc" section of the Orthanc Book (you can experiment C-Find at the command-line using findscu):

http://book.orthanc-server.com/dicom-guide.html#dicom-find

For the latter (REST API), please have a look at the "/tools/find" URI:

http://book.orthanc-server.com/users/rest.html

Samples for calling "/tools/find" are available part of the integration tests of Orthanc:

https://goo.gl/HcAQLA

At your own risk, you could also do low-level SQL relational queries against the underlying database (SQLite or PostgreSQL), but this might result in data inconsistencies or corruptions, as Orthanc implements proper locking of the database:

http://book.orthanc-server.com/faq/orthanc-storage.html

HTH,

Sébastien-

[geke]

Hello Sébastien,

Let me try to clarify my question. I use standard DICOM C-Find queries. I have seen that orthanc can handle relational queries which mean that i can query on image/instance level without supplying series, study UID etc.  in the query request which is mandatory needed when doing basic hierarchical queries. 

My question is now. There exists a extended association negotiation mechanism which can be used to check if a PACS supports relational queries.

http://dicom.nema.org/dicom/2013/output/chtml/part04/sect_C.5.html

see SOP Class Extended Negotiation

I dont have implemented extended association negotiation yet.

Can you tell me if orthanc will handle the extended association negotiation?

When orthanc supports extended association negotiation will it reply in the association response that it supports relational queries?

I hope that my question is now more clear to you.

Greetings Gerd

[Sébastien Jodogne]

Dear Gerd,

Sorry, I thought you were referring to relational queries in the field of SQL, not in DICOM C-Find ;)

For the time being, Orthanc does not support extended association negotiation, and there is no mid-term plan to work on its support.

I have added this feature on our long-term roadmap to keep track of it:

https://bitbucket.org/sjodogne/orthanc/commits/85a22aad7dfe97ef8a156b53ee738532c4f1599b

Regards,

Sébastien-