Measurement of elastic moduli of tissue components in atherosclerotic plaques by ultrasonic phased tracking method

Circulatory diseases such as the myocardial infarction and cerebral infarction are often caused by the rupture of the atherosclerotic plaque. For diagnosis of the vulnerability of the atherosclerotic plaque, it is important to characterize tissue components, which compose the atherosclerotic plaque, because the vulnerability of the atherosclerotic plaque relates to the amount of lipid and thickness of the fibrous cap. For characterization of tissue components in the atherosclerotic plaque, we have developed a new method, namely phased tracking method, to measure the regional elastic modulus of the atherosclerotic plaque using the transcutaneous ultrasound. For diagnosis of the vulnerability of atherosclerotic plaques, the knowledge of the elastic moduli of tissues such as the fibrous tissue and lipid provides useful clinical information. Based on elastic moduli of these tissues, thickness of the fibrous cap and the amount of lipid will be supposed from the in vivo measurement of the elasticity distribution. In this paper, elastic moduli of tissues in the atherosclerotic plaque are investigated from in vitro experiments using the phased tracking method.