Prostate segmentation in 3D US images using the cardinal-spline-based discrete dynamic contour

Our slice-based 3D prostate segmentation method comprises of three steps. 2) Boundary deformation. First, we chose more than three points on the boundary of the prostate along one direction and used a Cardinal-spline to interpolate an initial prostate boundary, which has been divided into vertices. At each vertex, the internal and external forces were calculated. These forces drived the evolving contour to the true boundary of the prostate. 3) 3D prostate segmentation. We propoaged the final contour in the initial slice to adjacent slices and refined them until all prostate boundaries of slices are segmented. Finally, we calculated the volume of the prostate from a 3D mesh surface of the prostate. Experiments with the 3D US images of six patient prostates demonstrated that our method efficiently avoided being trapped in local minima and the average percentage error was 4.8%. In 3D prostate segementation, the average percentage error in measuring the prostate volume is less than 5%, with respect to the manual planimetry.