A Novel Approach on the Colon Wall Segmentation and Its' Application

To measure the thickness of the colon is of much significance for colonic polyps detection in computed tomographic colonography (CTC). For achieving this target, to extract the boundary of both inner and outer colon wall accurately will be the prime task. However, the low contrast of CT attenuation values between colon wall and the surrounding tissues limits many traditional algorithms to achieve this task. Current research work has been exploiting two steps for segmenting inner and outer colon wall: (1) Finding the inner colon wall; and (2) applying geodesic active contour (GAC) based level set to extract outer boundary of colon wall. However, when sticking presents between two colon walls, the task turns to be much more complicated and the threshold level set segmentation method may fail in this situation. In view of this, we present a minimum surface overlay model to extract the inner wall in this paper. Combined with the superposition model, we are able to depict the outer wall of colon in a natural way. We validated the proposed algorithm based on 60 CTC datasets. Compared with the GAC model, the new presented method is more reliable for the colon wall segmentation. Additionally, the application for the wall thickness also provided us with any hints on the colonic polyps detection.