Facing issue with image visualization in XNAT

[Leo Abhi]

I’m facing an issue on my XNAT instance where the OHIF viewer shows the following error when trying to visualize images:

“Error displaying current frame”
“Unknown error”

To investigate, I downloaded the same case and uploaded it to my local XNAT instance, where it displayed normally without any issues. While comparing configurations between production and local setups, I noticed that Custom DICOM Routing Rules were enabled on production but not locally.

 

As part of debugging, I copied those same routing rules to my local XNAT to see if they were related to the issue, and that allowed me to replicate the same “Error displaying current frame” problem locally. However, I’ve since discovered that I’m unable to fully reverse or clear the DICOM routing rules, even after disabling them in the admin panel. Because of this, I’m now facing the same issue both locally and in production. 

Both my production and local instances are using OHIF viewer version 3.7.1.

 

At this point, I’m trying to determine whether the DICOM routing configuration is indeed the cause of this issue, or if there could be another underlying reason for the “Error displaying current frame” error.

 

Any insights, suggestions, or troubleshooting directions would be greatly appreciated.

The image of the issue is attached below for reference

[Simon Doran]

Hi Leo,

  The connection between the DICOM routing rules and the behaviour of the viewer is not clear to me. In order to investigate what's happening here, there are a few things that you could do:

1. Navigate to the session containing the image that is now un-viewable, locate the DICOM series involved and download the image from XNAT. Then try and read this image into another DICOM viewer (e.g., OsiriX or Horos on a Mac, or RadiAnt on a PC).
   
   
2. Inspect the DICOM metadata in the XNAT webapp.
   
   
3. View the image in the XNAT OHIF viewer with your web browser's Developer tools open. Look for errors in the "Console" tab and see if anything informative appears.
   
   
4. If you have access to the XNAT backend server - presumably, you do for your local installation - go to the directory /data/xnat/home/logs. Immediately after trying to view the image, type the command ls -lt | head -n 10 to view (say) the 10 most recently logged errors. Inspect any log files that were modified at the time you tried to view the image.

  Given a bit more information, it might be possible to track down what is happening. It would also be helpful to know what modifications were made to the routing rules. The description of what you actually did doesn't really provide enough information to replicate the problem, particularly the part where you say "I’ve since discovered that I’m unable to fully reverse or clear the DICOM routing rules."

  Best wishes,

Simon

[Leo Abhi]

Hi Simon,

 

Thank you for the detailed steps. I’ve followed your suggestions and gathered the information below to help investigate the issue further.

1. Viewing the DICOMs in another viewer:
   I downloaded the affected session from XNAT and was able to successfully open the images in Weasis, Horos locally, confirming that the DICOM files themselves are intact.
   
2. Inspecting the DICOM metadata:
   The metadata visible in the XNAT web application appears consistent and does not show any missing or incorrect tags.
   
3. Browser Developer Console output:
   When loading the unviewable session in the OHIF viewer, the browser’s Console tab reports the following errors:

           I’ve attached a screenshot showing these errors for reference.

           

4. XNAT logs:
Immediately after attempting to open the image, I checked the most recently modified log files under /data/xnat/home/logs.
In particular, the restlet.log contained the following relevant entries:

 

ERROR org.nrg.xnat.restlet.resources.QueryOrganizerResource - Unknown alias "URI" processing query for root element: imageScanData
ERROR org.nrg.xnat.restlet.resources.QueryOrganizerResource - Unknown alias "URI" processing query for root element: subjectAssessorData

 

java.lang.NullPointerException: null    at org.nrg.xnat.restlet.resources.search.SearchFieldListResource.getRepresentation(SearchFieldListResource.java:246)

 

ERROR org.nrg.xnat.restlet.resources.ConfigResource - Configuration service error replacing config for user admin and project null on tool [dicom] path [subjectRules/sessionRules]

Failed to load resource: the server responded with a status of 404
/xapi/ohifroiColor/...
/xapi/ohifiaa/...
/xapi/ohifiaa/servers
/xapi/viewerConfig/projects/Test_04

 

1. I’ve also attached the corresponding log file for your review.

For context, the DICOM routing rules currently enabled on the XNAT instance are:

• Project Routing: (0008,0080):(.*)
• Subject Routing: (0010,0020):(.*)
• Session Routing: (0008,0081):(.*)

When I reproduced the same configuration locally, the same “unviewable” behavior appeared — disabling the routing rules did not immediately fix it. The scans remain viewable in Weasis, but the OHIF viewer consistently fails to render them, suggesting that the routing configuration might be affecting how the viewer references or queries session data internally.

Please let me know if you’d like me to share any additional logs (e.g., access.log or ohifviewer.log) or DICOM metadata extracts for a deeper look.

 

Best regards,
Leo

[Leo Abhi]

My files didn’t upload successfully for some reason. The problem still seems to persist. Could you please advise what might be causing the issue?