Working with Private Tags in Orthanc

[Saad_Afridi]

Hello! So I’ve been trying to instantiate new private tags in orthanc, I have already looked at the following resources:

Advanced features of the REST API — Orthanc Book documentation (orthanc-server.com)
Private DICOM Headers Within Orthanc (oak-tree.tech)
and other posts related to private tags in this google group.

However, I’m still having trouble working with private tags. The tags aren’t being registered properly (show in screenshots). Any help is greatly appreciated!

Here are all the relevant screenshots:

Example orthanc.json change for dictionary:

Example Request (python) to tools/create-dicom:

How it appears on orthanc:

Result from http://…/instances/…/tags

Is this working as intended or have I went wrong somewhere? I would want it to show RHScore and RHPositivity on orthanc.

Thank you for all the help!

[alainmazy]

Hi Saad,

Thanks for the detailed report !
I think you are right and the output is not as expected.

I’m copy pasting here some of my findings and thoughts. I will continue to investigate later.

“Dictionary”: {
“2001,0015”: [“IS”, “RHScore”, 1, 1, “TECH COMPANY”],

“2001,0017”: [“IS”, “RHPositivity”, 1, 1, “TECH COMPANY”]
},

This is how private elements are defined in DCMTK: https://github.com/DCMTK/dcmtk/blob/master/dcmdata/data/private.dic

When added into a file, the 00 shall be replaced by the PrivateCreator defined locally:
The expected output should be something like:
2001,0010: PrivateCreator: TECH COMPANY → defines ‘2001,10…’ as an alias for TECH COMPANY
2001,1015: RHScore: 6 → uses ‘10’ to show that this is a TECH COMPANY private tag
2001,1017: RHPositivity: TRUE

Right now, Orthanc does not include the 2001,0010 PrivateCreator “alias” definition. This command line
curl -H “Content-Type: application/json” -X POST http://localhost:8044/tools/create-dicom -d ‘{“Tags”: {“PatientID”: “toto”, “RHScore”: “6”, “RHPositivity”: “TRUE”}, “PrivateCreator”: “TECH COMPANY”, “Content”: “data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==”}’

Gives this output where 2001,0010 PrivateCreator is missing:

Right now, I have no workaround to suggest to include private dicom-tags correctly with tools/create-dicom. I will continue to investigate a bit later.

Best regards,

Alain.

[alainmazy]

Hi Saad,

My bad, we both missed some important information in the documentation.

I have just updated it to, hopefully, make it clearer for all of us, including myself

Hope this helps,

Alain.

[Saad_Afridi]

Awesome, thanks a lot for the explicit explanation with screenshots !