Segmentation

Segmentation in Prism is an optional advanced workflow. Not every site enables it, and it requires volumetric (or otherwise segmentable) data and editor permissions. When present, a Segment toolbar group controls brushes, segment groups, and visibility.

Who uses segmentation here

• Research and teaching cases where a quick manual mask is enough.
• Multi-disciplinary tumor boards to highlight a region of interest on a volume before export or screenshot.
• Verification of auto-segmented inputs when those arrive as DICOM-SEG in future integrations (availability depends on deployment).

Regulatory contouring for radiotherapy planning usually remains on a dedicated TPS; treat Prism as a viewer-first experience unless your organization qualifies it for more.

Segment groups

• The viewer maintains groups of segments (analogous to measurement groups) with an active group and a list of segments with on/off visibility and names.
• You can add segments (when the UI exposes Add segment), toggle the whole segmentation overlay, and sometimes import or lock if data came from a structured source (read-only for protected content).

Use case: mark a VOI in green for a resident before conference.

Use case: mark spleen vs liver in two named segments in the same group, then hide spleen to see liver-only windowing checks.

Tools

• Brush / Eraser — volumetric or slice-wise painting depending on viewport kind and engine state.
• Segmentation and 3D features interact: some segment operations only apply in volume or MPR cells.

If tools are disabled: the active viewport may be 2D stack-only or the study lacks a loadable volume for brush editing.

Related

• Viewports and layouts — use 3d-main or MPR layouts to reach segment-friendly panes.
• Measurements and annotations — for linear measures instead of painted regions.