Microsoft.Health.Dicom.Client 10.0.535 throws Malformed DICOM json on FL/FD -Infinity

Package

• Microsoft.Health.Dicom.Client 10.0.535
• Microsoft.Health.FellowOakDicom 10.0.535 (pulled in by that client)

Used against Azure Health Data Services DICOM service WADO-RS GET …/studies/{uid}/metadata (application/dicom+json).

What happens

The DICOM service returns HTTP 200. For a private FL element whose IEEE value is −Infinity it emits a JSON string, because JSON has no numeric infinity:

"00232018": { "vr": "FL", "Value": ["-Infinity", -1] }

RetrieveStudyMetadataAsync then throws:

System.Text.Json.JsonException: Malformed DICOM json, number expected

The exception aborts the entire study enumerate. Callers see instance count 0 even though the service has the study.

Confirmations

• Replacing "-Infinity" with a finite number: client 10.0.535 succeeds.
• Same payload with fo-dicom 5.2.6 DicomJsonConverter: succeeds.
• Failure is client-side JSON parse, not WADO-RS retrieve.

Minimal JSON (no PHI)

RetrieveStudyMetadataAsync against a stub HttpMessageHandler that returns application/dicom+json:

[
  {
    "00720076": {
      "vr": "FL",
      "Value": ["-Infinity", -1]
    }
  }
]

Expected: two FL values, NegativeInfinity and -1.
Actual on 10.0.535: JsonException.

This repo’s current main client uses stock fo-dicom (not the old FellowOakDicom fork). Bumping fo-dicom to 5.2.6 and adding that stub-handler test locks the behavior. A published Microsoft.Health.Dicom.Client after that bump is what 10.0.535 consumers need.

Ask

Please treat this as a Microsoft.Health.Dicom.Client bug, merge the accompanying PR, and publish a new package.

No patient identifiers in this report.

Start at RetrieveStudyMetadataAsync and inspect how the current main client uses stock fo-dicom to parse application/dicom+json. Reproduce the payload with a stub HttpMessageHandler, then verify that the dependency update and test accept FL values of -Infinity and -1 without aborting study enumeration.