DICOM PS3.18 2021e - Web Services
10.4.3.3.4 Thumbnail Resource Payload

The payload for a Thumbnail Resource (see Section 10.4.1.1.4) shall contain a meaningful representation in a Rendered Media Type. The origin server will determine what constitutes a meaningful representation. The Thumbnail shall not contain any Patient Identifying Information. Only a single image shall be returned.

The origin server may return a redirection response (HTTP status code 302) to a rendered resource instead of returning a rendered image.

There is no requirement that the representation be related to any Icon Image Sequence (0088,0200) encoded in Instances or returned in query responses.

DICOM PS3.18 2021e - Web Services