A method for determining and graphically marking a position within a lumen of the body of a patient indicative of occlusion includes providing a user interface, using a processor, configured to allow a user to select an occlusion percentage threshold, determining, using the processor, a percentage of occlusion in the lumen, comparing, using the processor, the determined percentage of occlusion with the selected occlusion percentage threshold and identifying a region of the lumen that is occluded more than the selected occlusion percentage threshold, and designating, using the processor, the identified region on an image of the lumen with at least one mark.
