Sup 243 - Label Map Segmentation

This supplement describes the addition of a Label Map Segmentation information object definition (IOD) to the DICOM Standard to encode classification of entities.

The current DICOM Standard supports an IOD and service-object pair (SOP) class for pixel- or voxel-based segmentation encoding. This allows for overlapping of segments but it is inefficient and difficult to encode large numbers of non-overlapping segmentations. This is because they require non-trivial processing to extract from the bit-plane-encoded data to assure there is no overlap, and to convert to the commonly used label map form.

The new IOD reuses existing data elements for describing segmentations where appropriate. Segment properties are conveyed in the existing segment description structure in order to be compatible with the existing bit-plane-segment descriptions. The existing palette colour photometric interpretation may also be used (instead of monochrome).

The scope of this supplement is confined to label maps for classes (what class a segment represents) but not instances (which instance of a class is represented). Scope is also limited to a single label map, which does not allow for overlap of different segments. If overlapping of multiple label maps is required, separate SOP instances may be created.

Main sections:

· Scope and field of application

· PS3.3 DICOM PS3.3 – Information object definitions

· PS3.4 DICOM PS3.4 – Service class specifications

· PS3.6 DICOM PS3.6 – Data dictionary

· PS3.16 DICOM PS3.16 – Content mapping resource