Structure boundary quality control

RTpipeline checks whether a segmentation mask reaches an image boundary. A boundary touch can indicate that part of a structure lies outside the acquired CT volume, but it is a screening signal rather than proof that a clinically important contour is incomplete.

What the check records

For each non-empty mask, the quality-control stage records:

• the image sides touched by the mask;
• whether any touch is in-plane rather than limited to the axial scan extent;
• whether systematic CT-cropping metadata is available; and
• the configured crop region and clamped axes, when present.

Axial-only touches are reported but do not by themselves make the overall QC status fail. In-plane boundary touches are treated as warnings unless the structure is explicitly excluded from status evaluation. This distinction helps separate limited scan length or planned axial cropping from possible left, right, anterior, or posterior truncation.

Interpreting a warning

Review the source CT and contour before excluding a structure. Common benign causes include support devices, the external body contour, or anatomy that normally extends beyond the planned scan range. Target volumes and organs at risk require closer review because incomplete coverage can invalidate volume, DVH, and radiomic measurements.

Downstream radiomics tables retain a structure_cropped flag. Cropped names may also carry the __partial suffix so that incomplete structures remain visible instead of being silently treated as complete.

Configuration

The cropping check can be skipped for faster QC when boundary assessment has already been performed elsewhere. When skipped, the report records a SKIP status and reason. For research workflows, keep the check enabled and define the handling of boundary-touching structures before statistical analysis.

Systematic anatomical cropping is configured separately. See CT Cropping for crop-region and landmark settings.