A method of generating a dissection curve between a first and a second object in a volume image. The method accesses volume image data of a subject as a set of image slices and identifies a region of the volume image data that includes at least the first and second objects. At least one starting point in the volume image data is defined for the dissection curve according to a geometric primitive entered by an operator. Successive dissection curve points are identified according to points of minimum intensity in successive image slices. The dissection curve that connects the identified plurality of successive dissection curve points is displayed.