OHIF Viewer
OHIF is an open source, zero-footprint DICOM viewer that reads studies over DICOMweb. Medplum's DICOMweb implementation targets the request sequence OHIF makes, so a study stored in Medplum can be displayed without a gateway or a separate image server in between.
Medplum hosted cloud
Medplum's hosted cloud is preconfigured with an OHIF instance at viewer.medplum.com. There is nothing to deploy and nothing to configure — sign in with your Medplum account and the studies in your project are there.
The viewer authenticates against Medplum with OAuth2 and reads over the same DICOMweb API documented here, so what you see in it is exactly what any DICOMweb client would get.
Self-hosted viewer deployments
Running your own OHIF deployment against a self-hosted Medplum server is an enterprise feature. Contact us at hello@medplum.com to talk through it.
How OHIF uses the API
| OHIF screen | Request | Status in Medplum |
|---|---|---|
| Study list | GET /dicomweb/studies?limit=101&offset=0&fuzzymatching=false&includefield=00081030,00080060 | Works; parameters are ignored |
| Study → series | GET /dicomweb/studies/{studyUid}/series | Works |
| Series metadata | GET /dicomweb/studies/{studyUid}/series/{seriesUid}/metadata | Works |
| Image display | GET /dicomweb/studies/{studyUid}/series/{seriesUid}/instances/{instanceUid}/frames/{frame} | Works, one frame per request |
Image retrieval goes through WADO-RS, not WADO-URI — Medplum implements frame retrieval and does not implement WADO-URI at all. Any DICOMweb viewer pointed at Medplum needs to be configured the same way.
Authentication and access control
The /dicomweb endpoints use the same OAuth2 bearer tokens as the rest of the Medplum API, and
resolve against the authenticated user's project and access policy.
A user who cannot read a DicomStudy cannot retrieve it in the viewer either — imaging inherits the
project's existing authorization rather than introducing a second model to keep in sync.
CORS is enabled on the /dicomweb/ prefix, so a viewer served from a different origin can call the
API directly from the browser.
FHIRcast
OHIF hardcodes its FHIRcast hub URL to /api/hub. Medplum aliases that path to the latest FHIRcast
version it supports, so OHIF's context synchronization works against a Medplum server without
reconfiguration. See FHIRcast for what context synchronization enables — driving
the viewer's displayed study from a clinician's selection elsewhere in the application.