XDS-I Registry Metadata Extensions - Detailed Proposal

1. Proposed Workitem: XDS-I Registry Metadata Extensions - Detailed Proposal

Proposal Editor: David Heaney
Editor: David Heaney
Domain: Radiology

Summary

A lot of XDS Affinity Domains are extending the XDS Registry metadata to include certain radiology specific information: Study Instance UID, Accession Number, etc. Currently this is being done in a purely customized manner so for example, two Registries that have added support for Study Instance UIDs will not have done it in the exact same way.

This work item proposes that IHE Radiology define a standardized way of extending XDS metadata. For example, it could be specified that the DICOM attribute Tag number shall be used in a specific way if a DICOM attribute is to be used in the metadata.

To a large extent this work item will be dependent upon work done in IHE ITI as the ITI Technical Committee needs to define the generalized way in which XDS metadata can be extended. IHE ITI has indicated that they have already begun work on this effort. There is still work that IHE Radiology could do while waiting for the output of ITI, such as defining the list of common metadata attributes extensions desired for XDS Affinity Domains.

2. The Problem

A lot of XDS Affinity Domains are extending the XDS Registry metadata to include certain radiology specific information: Study Instance UID, Accession Number, etc. Currently this is being done in a purely customized manner so for example, two Registries that have added support for Study Instance UIDs will not have done it in the exact same way. If would be better if there was a standardized way of extending XDS metadata. For example, it could be specified that the DICOM attribute Tag number shall be used in a specific way if a DICOM attribute is to be used in the metadata.

3. Key Use Case

Metadata is typically being extended in order to improve performance. Putting key Study Level attributes in the XDS Registry means that many Study level query use cases can be supported by a Consumer only having to query the Registry rather than also having to query the Repositories as well to retrieve and parse the XDS-I.b Manifests.

4. Standards and Systems

XDS

5. Discussion

This should really probably be an ITI Domain Work Item proposal to try and standardize the extension of XDS metadata but I wanted to capture the issue. Extension of metadata to include the Study Instance UID, CP-RAD-188, was already rejected in the past.