Using fuzzy logic for morphological classification of IVUS-based plaques in diseased coronary artery in the context of flow-dynamics

Plaque morphology in a diseased coronary artery plays a significant role in the modification of the fluid flow characteristics. The plaque morphology of forty-two patients who underwent IVUS (intravascular ultrasound) procedure was quantified by degree of membership in four fuzzy logic sets, which we refer as type I: protruding, type II: ascending, type III: descending, and type IV: diffuse. Of 42 cases, 28% were of type I, 18% type II, 20% type III and 23% type IV, 6% belonged to hybrid types (partial members of multiple types) and the remaining 5% did not fit in any category. The degree of membership is of significance as the inter-class blood flow patterns (those strongly members of the same set) are similar to each other compared to the intra-class behavior, indicating plaque morphology (shape of blockage) is an important metric in addition to the degree of stenosis to represent the flow characteristics in a diseased stenotic coronary artery.