Abdominal CT registration using Elastix

[lassoan (Andras Lasso)]

You can create a mask by using Segment Editor . You can use any effect, such as simple paint with a large brush, or scissors (fill in from one viewpoint then cut the two ends from another viewpoint), or using Surface Cut effect (provided by SegmentEditorExtraEffects extension). Then you can export the segment to a labelmap by right-clicking on the segmentation in Data module and choosing export to labelmap volume.