Ex vivo characterization of atherosclerosis using intravascular photoacoustic imaging

The assessment of plaque composition is one of the important steps in the interventional management of atherosclerosis. The difference in the optical absorption between the arterial wall and plaque constituents could be utilized to obtain high resolution photoacoustic images. Therefore, intravascular photoacoustic (IVPA) imaging has the potential to play a major role in the detection and differentiation of atherosclerotic lesions. Using a rabbit model of atherosclerosis, we performed ex vivo imaging studies to evaluate the ability of IVPA imaging to detect the presence of inflammation in the plaque. Specifically, the difference in the magnitude of the photoacoustic response from the free lipids, macrophage foam cells, blood and the rest of the arterial wall were used in detecting the fibrocellular inflammatory plaque. The constituents identified in the IVPA images were confirmed by the results from histology. (C) 2007 Optical Society of America.