DICOM PS3.17 2021e - Explanatory Information

PPPP.8 Storage Considerationa

PPPP.8.1 Creating IOD From DICOM-RTV Streams

It is reasonable to take some or all of an DICOM-RTV stream to create storage DICOM IOD. Transcoding the patient metadata and video content should be relatively straightforward. Some of the issues that have to be considered include how to get information describing origin equipment, etc.

Storage of video data, even received in real-time, is possible. However, how to initiate a DICOM-RTV stream based on a stored video is presently not described in the standard. Also, how to encode directly a received DICOM-RTV stream into a DICOM Video Instance is not fully described. An external decision (manual or automatic) is required to specify at least the start time and the end time of the portion of the stream to be stored. However, some principles can be established to ensure that receiving applications will actually find in the DICOM-RTV flow all the data items needed for the replay or storage of this data using DICOM Storage services. Regarding storage of this data using DICOM Storage services:

  • "Pixel Data" and "Waveform Data" attributes of the DICOM (video) Composite Objects should be mapped from the corresponding payloads in media (e.g., video and audio) flows and associated SDP objects;

  • The metadata attributes of the DICOM composite objects should be mapped from the DICOM-RTV metadata flows; attributes applicable to all frames (e.g., included in the Current Frame Functional Group Sequence) should be mapped from the static part of the DICOM-RTV metadata; attributes applicable to a single frame (e.g., Per-frame Functional Group Sequence) should be mapped from the dynamic part of the DICOM-RTV Metadata;

  • The "Cine" and "Multi-frame" modules, as well as the "Number of Waveform Samples" attribute, not present in the DICOM-RTV Metadata, are built from the values of the RTV Meta Information (e.g., Sample Rate) , the dynamic payload of the relevant flows (e.g., Frame Numbers) and the external decisions (e.g., Start Time) ;

  • Based on the choice of the application and on the possible presence of a DICOM-RTV Rendition flow, the DICOM composite object to be stored may gather or not the individual essences of the DICOM-RTV flows (e.g., video and audio contents in a single SOP instance using a MPEG2 Transfer syntax).

DICOM PS3.17 2021e - Explanatory Information