Collision on resource IDs

Hi orthanc group! :slightly_smiling_face:

I wanted to ask a quick question: is it possible to have collision on the resource IDs of DICOM generated by different equipments? Or it’s a kind of universally unique ID?

Thanks in advance.


The topic of the DICOM/Orthanc IDs and their uniqueness is discussed in the Orthanc Book:



Hi everyone,

I read the documentation, and I understood that it’s possible that we have collisions at the Patient level. I’d like to explain my context to see if anyone can give me an idea.

I’m doing experiments with Orthanc for a network of clinics. Each clinic will have a local installation of Orthanc (client) getting the images from the equipments and rerouting to an installation of Orthanc on the cloud (server). From the business’ perspective, the valid source of truth is Orthanc server. All instances from the clients will be deleted after uploaded to the server.

Given that the images will be created in separate instances of Orthanc and sent to another Orthanc, I assume we may have many opportunities for collisions on the Resource IDs.

Does anyone have an idea on how to make sure we won’t have any collisions? We are using the HighPerforrmanceAutoRouting python script to route the images.


(1) In the case of possible collisions at the “patients” level, simply use the “studies” level throughout your application. The “Study Instance UID” is indeed guaranteed to be unique by the DICOM standard.

(2) The “HighPerformanceAutoRouting” sample script works at the “instances” level (not at the “patients” level), so it is safe to use it in presence of “Patient ID” collisions.