DICOM C-Find SCU at Instance Level on remote modality

Hello there,

First of all thanks again to Sebastien for his incredible job on Orthanc. It's a pleasure to be able to handle and control DICOM data via Orthanc.

I was trying to query and retrieve via CURL on Patient, Study and Series level. So far everything worked fine.

However I cannot seem to get any proper answer on an instance level:

curl http://orthanc:8042/modalities/station/query/ -X POST -d '{"Level" : "Instance", "Query" : {"SeriesInstanceUID" : "1.2...740"}}'

I even tried with the SOPInstanceUID that I was trying to retrieve, but I had no answer on this either.

I know that I can retrieve or push these using DICOM workstations. I've successfully retrieved exams via Orthanc but not single instances. Am I doing something wrong?

Thanks in advance for your help!




I am able to query at the instance level using the same syntax as yours:

curl http://localhost:8042/modalities/station/query/ -X POST -d ‘{“Level” : “Instance”}’

In my test framework, I use 2 instances of Orthanc talking to each other.

I therefore highly suspect that your modality “station” does not support query/retrieve at the instance level. What is the manufacturer of “station”? Have you specified this manufacturer inside the “DicomModalities” section of the Orthanc configuration file?


Thank you for your fast reply!

The workstation I’m trying to pull from is a GE AW. I’ve tried pulling one image between two workstations with success. Is there a specific 4th parameter for these types of workstations I should use in the config file?

Any request at the Instance level remotely is super fast and comes empty. Maybe the workstations is refusing queries? I’ll try and look at the remote declaration of Orthanc.



No, there is no 4th parameter for GE AW.

You should definitely get in touch with the support team of GE to know whether query/retrieve at the instance level is supported.


Thank you for your help! I’ll inquire about this if possible.

Right now I’m pulling the whole series to circumvent this little hiccup!

Having the author confirming I’m not doing anything wrong with my initial REST request is already a great thing.

Thanks for your time!



Hi, I have the same problem, Did you have solve the problem?

My group encountered the same issue. It seems Orthanc is sending the wrong query level, instead of IMAGE it sends INSTANCE, which is not DICOM compliant. Looks like Orthanc can handle both, that is why if you only test against Orthanc the image level query seems to work, but dcmtkqrsp and other systems we’ve tested will not work.


Yes, it seems that Orthanc uses “INSTANCE” per default while the DICOM standard only specify “IMAGE” (http://dicom.nema.org/medical/dicom/2015c/output/chtml/part04/sect_C.6.2.html#table_C.6.2-1).
I’ll fix Orthanc such that it uses IMAGE per default.

As a workaround with Orthanc 1.5.8, if you declare your modality as “ClearCanvas”, “Dcm4Chee” or “GE”, Orthanc will use the “IMAGE” identifier in the C-Find SCU:

Best regards,


FYI, link to the fix: https://bitbucket.org/sjodogne/orthanc/commits/bdafff1ce443d8d7669505294393581bff4e43bc

Thanks for the quick response and fix !