Characterization of Atherosclerosis Plaque in OCT Images Using Texture Analysis and Parametric Equations

It has been long thought that the main cause of a heart attack is the narrowing of an artery from the buildup of fatty plaque inside the artery wall. Postmortem autopsy studies on patients who have died after a myocardial infarction (heart attack) found that many of those did not have their arteries severely narrowed by plaque. Instead, thrombosis (blood clots)near ruptured lesions were identified as the actual main cause. The search for the type of culprit lesions has established that the formation of a lipid-rich pool covered by a thin fibrous cap(thickness less than 65 micrometer) was structurally unstable and likely to rupture. Subsequently, the term vulnerable plaque has been used to refer to this type of plaque. Optical Coherence Tomography (OCT) is a new imaging modality capable of providing the required micrometer scale resolution to detect such tissue. With a resolution of approximately15 micrometer, OCT is considered the most promising imaging modality for identifying vulnerable plaque. We present a complete framework for reliable tissue characterization of different plaque types using OCT images. Our framework utilizes texture analysis as delineating features. In addition, a parametric classification technique is presented. The characterization performance of the proposed framework is assessed and evaluated.