1. A method of identifying a border of a vascular object, comprising: acquiring imaging data representative of a vascular object; using a first set of blood-vessel data from the imaging data to approximate a border on a first image of the vascular object; identifying at least one control point on the border on the first image of the vascular object; extrapolating the at least one identified control point to a second set of blood-vessel data from the imaging data to define at least one other control point on a second image of the vascular object; using the at least one other control point to approximate at least one other border on the second image of the vascular object; and adjusting a position of the at least one other border on the second image in accordance with at least one factor selected from the group of factors consisting of: a gradient factor, a continuity factor, and a curvature factor.