Some more segmented atriums

Segmenting each atrium takes less than about 10 minutes. Here is an atrium segmented showing all four PV drainages.

The points around the left atrium are the local maximum points, and the red-background is the EDT map of the original image. With little training, it is fairly easy to segment the PV drainages using this method. In the final segmentation step, the user picks local maximum points, and the voxels which are part of the basic component centered by these local maximum points are revealed. The user must be trained before-hand on which local maximum points to pick. It is a fairly trivial task to pick local maximu points on the PV drainages, since the local-maximum points in the PV drainages lie roughly around a straight-line