The Study of Human Atherosclerosis by Polarization-Sensitive Optical Coherence Tomography

Atherosclerosis is unquestionably the leading cause of morbidity and mortality in developed countries, and the world-wide importance of acute vascular syndromes is increasing. Rupture of atherosclerotic plaque has been identified as the proximate event in the majority of cases of acute ischemic syndromes. Therefore, modalities capable of characterizing the atherosclerotic lesion may be helpful in understanding its natural history and detecting lesions with high risk for acute events. Optical coherence tomography (OCT) is a powerful tool capable of tomographic imaging based on low coherence interferometry. It is analogous to ultrasound imaging except that it uses infrared light instead of sound. Polarization-sensitive optical coherence tomography (PS-OCT) combines the advantages of OCT with additional image contrast of the sample. The added contrast is based on the ability of PS-OCT to detect the birefringent properties of a sample (phase retardation and fast-axis orientation) simultaneously. The goals of this project are: 1) to examine whether PS-OCT is an acceptable tool for the characterization of typical plaque constituents; and 2) to explain the correlation between birefringence and forming or rupture of a plaque; and 3) to establish a quantitative PS-OCT image criteria for atherosclerotic plaque characterization in vitro.