1. A method of segmenting a digitized medical image comprising the steps of: providing a digitized image of an anatomical region, said image comprising a diffusion tensor field corresponding to a domain of points on an 3-dimensional grid; partitioning said image into 2 regions, wherein each point is initially assigned to one of said regions; associating a level-set function with each region, wherein said level-set function has a negative value in one region and a positive value in the other region; calculating a mean value of said diffusion tensor field over each of said 2 regions; initializing an energy defined as a functional of said level-set functions and said diffusion tensor field; changing the region membership of each point in said image if the energy functional value decreases as a result of said region membership change and updating said mean value of said diffusion tensor field over each of said 2 regions; and obtaining a segmentation of said image when the magnitude of the change of said energy function value resulting from changing the region membership of a point is less then a predetermined threshold.