Displaying DICOM images and corresponding DICOM-SEG segmentations in the OHIF viewer (orthanc plugin)

Support
1

I am testing the functionality of displaying some DICOM-SEG segmentations in OHIF.
I am using the OHIF Viewer plugin for the ORTHANC server to display my example CT scans in DICOM format (.dcm) and a test segmentation in DICOM-SEG format.

In summary, the steps I took:

  1. Uploaded a patient CT scan in Slicer3D
  2. Created a segmentation object on 1 slice (DICOM-SEG)
  3. Exported in DICOM (.dcm) - when I test in the DICOMbrowser in Slicer3D, I see two series: one corresponding to the CT images (modality: CT), the other to the segmentations (modality: SEG)
  4. Manually uploaded the .dcm file with the two series (CT, SEG) in the ORTHANC server
  5. Tested the correct export of the file by viewing the series using the button “Open OHIF viewer” (see the image below)

I navigate to the OHIF viewer through this button:

Screenshot 2024-10-09 at 10.49.54
Screenshot 2024-10-09 at 10.49.541308×609 97.2 KB

Result: Failed test, I can see only the CT scans and not the segmentation. I get this error in the console:

Error: Unsupported displaySet
    at HangingProtocolService.getViewportsRequireUpdate (index.js:32:2)
    at onDoubleClickThumbnailHandler (19.bundle.0aeb63febb9656960795.js:1167:49)
    at onDoubleClick (index.js:32:2)
    at Object.Rb (index.js:32:2)
    at Xb (index.js:32:2)
    at Yb (index.js:32:2)
    at Ze (index.js:32:2)
    at se (index.js:32:2)
    at index.js:32:2
    at Jb (index.js:32:2)

A reply to a previous thread mentioned importing an extension, but below I explain why I think it might be something else.

According to the ORTHANC server documentation about the OHIF plugin, “[…], the OHIF plugin for Orthanc only packages official releases of OHIF”. Therefore, my assumption is that the DICOM-SEG should work correctly through the indicated button, since I see other examples of SEG series in the OHIF viewer website correctly displayed. If they are the same OHIF version, they should be using the same extensions.

I think the issue could lie in incorrectly exporting the DICOM-SEG file, so I wanted to make sure I understand the right protocol for linking the segmentations to CT scans, for example by ensuring matching DICOM Series UID between the CT scans and segmentation, or other similar conditions.

I would greatly appreciate it If anyone could comment on the process I described, my assumption about the OHIF software version for the ORTHANC server plugin, and my doubt on the correct linkage between medical images and segmentations, thanks.

2

Hi Victoria-Bruno,

It seems like the issue might be related to how the DICOM-SEG file was exported or linked to the CT scan. Here are a few things you can check:

  1. Series UID Matching: Ensure that the DICOM-SEG and the CT scans share the same Series Instance UID. This is critical for OHIF to properly link them.
  2. Check DICOM-SEG Export: Verify that the segmentation export from Slicer3D is correct. You can use tools like DICOMBrowser to inspect the metadata and ensure it’s valid.
  3. OHIF Extensions: OHIF supports DICOM-SEG natively, but ensure that the necessary extensions are available in the OHIF version bundled with Orthanc. Check the OHIF documentation here: OHIF DICOM Segmentation.
  4. Console Error: The error suggests an issue with creating the display set for the SEG file. Double-check the metadata consistency between the CT and SEG files.

You could also try loading the DICOM-SEG directly into the standalone OHIF viewer to see if it works outside of Orthanc.