Automating prostate capsule contour estimation for 3D model reconstruction using shape and histological features

Currently there are few parameters that are used to compare the efficiency of different form of cancerous prostate surgical removal. An accurate assessment of the percentage and depth of extra-capsular soft tissue removed with the prostate by the various surgical techniques can help surgeons determining the appropriateness of surgical approaches. In order to facilitate the reconstruction phase and thus provide a more accurate quantitation results when analyzing the images, it is essential to automatically identify the capsule line that separates the prostate capsule tissue from its extra-capsular one. However the prostate capsule is sometimes unrecognizable due to the naturally occurring intrusion of muscle into the prostate gland. At these regions where the capsule disappears, its contour can be arbitrarily reconstructed by drawing a continuing contour line based on the natural shape of the prostate gland. In this paper, some mathematical equations that will be used to provide a standard prostate shape at various stages will be presented. This mathematical model can be used in deciding the missing part of the capsule. It will also be used in conjunction with Generalized Hough Transform to automatically determine the capsule line, thus provides more accurate results in the reconstruction phase as well as in the percentage of coverage and depth calculations of the extra-capsular tissue.