Imagery as the strategy for contouring: defining contour for vascular stenosis viewed from inside the vessel. A fuzzy image solution

Carotid endarterectomy is one treatment for recurrent stroke prevention. This is an operative method aimed at removing atherosclerotic plaque responsible for narrowing of the vascular lumen as well as superimposed thrombus formation. However, results of large randomized double-blind trials regarding the efficacy of this treatment are conflicting as to the benefit of surgery as it relates to the degree of preoperative stenosis (vessel narrowing). This difference in trial results is attributable to two different methods of measurement of stenosis of the internal carotid artery having been applied in the North American Carotid Endarterectomy Trial (NASCET) and European Carotid Surgical Trial (ECST). The ECST method of defining stenosis gives the definition of severe stenosis to more patients than does the former. The variability in stenosis measurement between the two clinical trials has led to therapeutic decision confusion. The ECST study shows better outcome for medical patients in the severe category for ECST compared to NASCET and lesser benefit from surgery detected for patients in ECST with severe stenosis when compared to those with severe stenosis in NASCET. We sought to find out if there was a fuzzy solution to this dilemma of the two different measurements of stenosis