Application of diffusion techniques to the segmentation of Mr 3D images for virtual colonoscopy

Abstract

MR imaging techniques could offer greater possibilities for virtual colonic examinations due to their unrivaled imaging of soft tissues and non radiating nature; however, today only computer tomography virtual colonoscopy systems can be found in clinical use because of data acquisition limitations. We investigate here the possibility of using magnetic resonance images for virtual colonic systems. To cope with the low signal to noise ratio of images, diffusion techniques are considered, which allows reducing the noise in the images while enhancing the frontier formed by the inner colon wall. The general ideas and theoretical foundations behind anisotropic diffusion and its relation to scale space transformations are analyzed, as well as their implementation in 3D. The results of diffusion are then used to derive a new adaptive thresholding segmentation technique. This technique is applied to segment the inner colon wall boundary, which opens the way to virtual colonoscopy based on MR imaging.