Mechanical evaluation of lipid accumulation in atherosclerotic tissues by photoacoustic viscoelasticity imaging.

Photoacoustic viscoelasticity imaging (PAVEI) is a technique that directly provides the morphology of biological tissues with correlative mechanical information. In this Letter, we demonstrate the use of PAVEI to successfully characterize early-stage atherosclerotic plaques. Lipid, as the main material in early plaque lesions, embedded in gelatin was imaged to test the feasibility of PAVEI. Atherosclerosis of rabbits was studied ex vivo, and the rabbit arteries were imaged to show the intrinsic contrast of PAVEI. Our results demonstrate that PAVEI can provide valuable viscoelasticity information for early detection of atherosclerotic plaques, which yields new insights into biomechanical diagnosis of cardiovascular diseases.