Analysis of Plaque in Ultrasound Carotid Artery Using Phase Based Distance Regularized Level Set Evolution

摘要

Atherosclerosis is a cardiovascular degenerative disease which leads to heart attacks and stroke. Formation of plaque in Carotid Arteries (CA) is the cause of atherosclerosis. Ultrasound imaging is a non-invasive, low cost, and widely preferred technique to detect the presence of plaque in CA. For analysis and diagnosis of atherosclerosis, segmentation of plaque is essential. In this work an attempt has been made to segment the plaque using Phase based Distance Regularized Level Set Evolution (DRLSE) method. From the segmented plaque various geometrical features such as plaque minor axis, major axis, area and the index, Aspect ratio (AR) and Normalized Wall Index (NWI) are used for analysis. Result shows that phase based DRLSE method is able to segment the plaque from ultrasound carotid arteries. Using phase congruency information, level set contour robustly converge to plaque edges by avoiding leakage. The mean values of plaque minor axis, normalized wall index and aspect ratio are found to be 73.35, 0.24 and 10.09 respectively. The index derived from the extracted features is able to differentiate the stable and unstable plaque. The stable plaque is found to have low range of NWI (0.10) and plaque that cause risks of stroke have increased NWI (0.44). Hence, this method of analysis could be used in early identification of stroke.