Hello,
I would like to report a performance issue that appeared after upgrading Orthanc from 1.12.6 to 1.12.10.
Orthanc Statistics
“CountInstances”: 24183765,
“CountPatients”: 133704,
“CountSeries”: 671615,
“CountStudies”: 383134,
“TotalDiskSize”: “26209282329275”,
“TotalDiskSizeMB”: 24995119,
“TotalUncompressedSize”: “31635319468676”,
“TotalUncompressedSizeMB”: 30169791
Environment
Orthanc version: 1.12.10
Previous working version: 1.12.6
OS: Windows Server 2016
Database: PostgreSQL for Orthanc index
Storage: DICOM files on filesystem
Orthanc runs as a Windows service
Client: RadiAnt DICOM Viewer 2025.2
Problem
After upgrading to Orthanc 1.12.10, studies are no longer displayed properly in RadiAnt when querying the server.
RadiAnt can connect to Orthanc successfully, but the study search is very slow and eventually fails. In the Orthanc logs I see that the association is established, C-FIND starts, and then later ends with:
Find SCP Failed: DIMSE Failed to send message
Peer aborted Association
So the connection itself is fine, but the response to C-FIND becomes too slow and the client aborts.
What I tested
I tried multiple things already:
-Added ExtraMainDicomTags
-Ran reconstruct for studies
-Disabled hybrid S3 plugin usage
-Ran VACUUM on PostgreSQL
Unfortunately, none of these solved the issue.
Important finding
I isolated the problem using /tools/find.
Fast request
This request is fast:
POST /tools/find
{
“Level”: “Study”,
“Expand”: true,
“Query”: {
“StudyDate”: “20260313-20260313”
},
“RequestedTags”: [
“StudyInstanceUID”,
“StudyDate”,
“StudyTime”,
“StudyID”,
“StudyDescription”,
“AccessionNumber”,
“InstitutionName”,
“PatientName”,
“PatientID”,
“PatientBirthDate”,
“PatientSex”
]
}
Also fast
This request is also fast:
OST /tools/find
{
“Level”: “Study”,
“Expand”: true,
“Query”: {
“StudyDate”: “20260313-20260313”
},
“RequestedTags”: [
“StudyInstanceUID”,
“ReferringPhysicianName”,
“InstitutionalDepartmentName”,
“PerformingPhysicianName”,
“NameOfPhysiciansReadingStudy”
]
}
Fast
This request is fast too:
POST /tools/find
{
“Level”: “Study”,
“Expand”: true,
“Query”: {
“StudyDate”: “20260313-20260313”
},
“RequestedTags”: [
“StudyInstanceUID”,
“ModalitiesInStudy”
]
}
Slow / hangs
But this request becomes very slow / hangs:
POST /tools/find
{
“Level”: “Study”,
“Expand”: true,
“Query”: {
“StudyDate”: “20260313-20260313”
},
“RequestedTags”: [
“StudyInstanceUID”,
“NumberOfStudyRelatedInstances”
]
}
So the issue seems to be specifically related to:
NumberOfStudyRelatedInstances
This also matches RadiAnt behavior, because RadiAnt appears to request this field in its C-FIND query, and then the whole query becomes too slow.
Conclusion
At this point, it looks like the slowdown is specifically caused by calculating or returning NumberOfStudyRelatedInstances at Study level after upgrading to Orthanc 1.12.10.
On Orthanc 1.12.6 this workflow worked acceptably with the same client.
Questions
- Is there any known regression or performance change in Orthanc 1.12.10 related to NumberOfStudyRelatedInstances?
- Is there a recommended way to optimize this field for Study-level C-FIND?
- Is there any option to disable or shortcut this calculation for DICOM C-FIND responses?
- Would you recommend a specific PostgreSQL maintenance or schema-related action for this case?
If needed, I provide:
-Orthanc logs
-configuration excerpts
-full RadiAnt C-FIND request content
I really need any help, thank you!
radiant_cfind_request.txt (2.1 KB)
orthanc_log_summary.txt (8.3 KB)
orthanc_config.txt (1.7 KB)
