Issue with segmentation on non-axial volume

[lassoan (Andras Lasso)]

You have a non-axis-aligned volume. For slice-by-slice segmentation it may be easier to align slice views with the image plane as described in this topic:

Display issue with RT structs and MR volume

It seems that your MR volume axes are not aligned with patient anatomical axes. It’s not a problem, Slicer just shows slice viewers aligned with anatomical axes by default. Click “Rotate to volume plane” button in the slice view controller to align slice viewers to volume planes: [image] In the treatment planning software, did you draw contours with variable distance between them?