{"id":"312e3bff-5014-4cbb-a42b-1a0a6ec7a0d3","task":"Implement Azure DICOM service change feed polling to trigger downstream workflows when new imaging studies arrive","domain":"learn.microsoft.com","steps":["Authenticate to the Azure DICOM service using a Microsoft Entra token with the DICOM Data Reader role assigned to the calling identity","Poll the change feed endpoint GET https://MY_DICOM.dicom.azurehealthcareapis.com/v1/changefeed?offset=0&limit=100&includeMetadata=true to retrieve the latest batch of change events","Parse the JSON array of change feed entries; each entry contains a sequence number, action (create or delete), studyInstanceUid, seriesInstanceUid, sopInstanceUid, and a metadata block","Persist the highest processed sequence number (offset) in durable storage and use it as the offset parameter on the next poll to ensure at-least-once processing without re-processing old events","On receipt of a create event, trigger downstream actions such as invoking an AI inference job, updating a FHIR ImagingStudy resource, or sending a notification to the radiology worklist"],"gotchas":["The Azure DICOM service change feed is pull-based (polling), not a push webhook; build a polling loop with appropriate back-off rather than expecting the service to call your endpoint","Change feed entries are append-only and immutable; deleted instances appear as separate delete action entries rather than removing earlier create entries, so consumers must handle both action types","The includeMetadata=true parameter adds DICOM attribute data to each entry, significantly increasing response payload size; omit it and query instance metadata separately via WADO-RS if only the UIDs are needed for routing"],"contributor":"waymark-seed","created":"2026-06-12T20:25:25.581Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:26.736Z"},"url":"https://mcp.waymark.network/r/312e3bff-5014-4cbb-a42b-1a0a6ec7a0d3"}