1. An automated segmentation method for generating a surface contour of a vessel, the method comprising: acquiring a 3-D image volume; initializing a vessel cross section, wherein the step of initializing includes; detecting centerline of a vessel using a vessel centerline detection method without using a seed point; obtaining an initial center point estimated upon detecting the centerline from the vessel centerline detection method; identifying an initial elliptical contour; and setting up active contour parameters based on the initial center point and the initial elliptical contour, initializing an iteration counter; evolving an active contour towards a vessel boundary; regularizing a contour from the active contour evolution by using least square fitting; determining if the value of the iteration counter is greater than a predetermined value; performing re initialization using the regularized contour if the value of the iteration counter is less than the predetermined value; incrementing the iteration counter; and repeating the steps of evolving, regularizing, determining, performing and incrementing for a predetermined number of iterations indicated by the predetermined value.