Evaluation of Progression of Arteriosclerosis by the Quantitative Assessment of Acoustic Tissue Characteristics Using Acoustic Microscopy

对动脉硬化进行定量评价是非常重要的。本研究的目的是通过用扫描声学显微镜测量动脉硬化活体组织的超声衰减和传播速度来阐明其声学特征，并通过这些指标来评估动脉硬化的进展。我们使用超声组织定征系统和扫描声学显微镜(HSAM-500S，450 MHz)。冠状动脉标本经尸检获得52例，切成4微米厚。根据光镜下内膜的病理表现，将其分为3组：正常组(21例)、早期硬化组(24例)和晚期硬化组(7例)。年龄与超声衰减、年龄与传播速度之间的关系没有统计学意义(…更重要的是。值得注意的是，早期超声衰减较低(1.7%)。-0.6分贝)，晚期较高(5.4分贝)。-0.8分贝)，而正常情况下为2.5分贝。-0.5分贝)，但传播速度在早期较慢(1611.9()SY。--[)53.0米/S)，进入高级阶段速度更快(2031.4秒)。-[)145.0米/S)，高于正常(1757.8米/S)。总而言之，超声衰减和传播速度都不受年龄的显著影响，但主要受病理性动脉粥样硬化的影响。此外，与冠状动脉的光学表现相比，这两个参数均呈现出非线性变化。由于传播速度与体积模数的平方根成正比，因此在较硬的组织中传播速度较快。因此，我们得出结论，与正常组织相比，在光学定义的疾病早期阶段，冠状动脉内膜显示出最初的软化，随后由于纤维化和钙化的加剧，晚期冠状动脉内膜变硬。较少

It is very important to evaluate arteriosclerosis quantitatively. The aim of this study is to elucidate acoustic characteristics of living tissue in arteriosclerosis by measuring the ultrasonic attenuation and propagation velocity with a scanning acoustic microscopy, and to evaluate the progression of arteriosclerosis by these indices.We measured ultrasonic attenuation and propagation velocity in the human coronary artery intima using acoustic microscopy. We used an ultrasonic tissue characterization system with a scanning acoustic microscopy (HSAM-500S,450MHz). Coronary artery specimens were obtained by autopsy from 52 patients and cut into 4 microns thick. Based on the pathological findings in the intima with an optical microscope, we classified them into 3 groups : normal (21specimens), early stages of sclerosis (24 specimens), and advanced stages of sclerosis (7 specimens).The relationships between age and ultrasonic attenuation, and age and propagation velocity were not statistica … More lly significant. Significantly, ultrasonic attenuation was lower in the early stage (1.7(]SY.+-[)0.6dB), and higher in the advanced stage (5.4(]SY.+-[)0.8dB) than in normal (2.5(]SY.+-[)0.5dB), while propagation velocity was slower in the early stage (1611.9(]SY.+-[)53.0m/s), and faster in the advanced stage (2031.4(]SY.+-[)145.0m/s) than in normal (1757.8(]SY.+-[)90.4).In summary, both ultrasonic attenuation and propagation velocity were not significantly affected by age, but were mainly influenced by pathological atherosclerotic change. In addition, both parameters showed non-linear change as compared with the optical findings of coronary arteries. Because propagation velocity is proportional to the square root of the bulk modulus, Propagation velocity is faster in harder tissue. We therefore concluded that coronary artery intima in optically defined early stages of disease showed an initial softening as compared with normal tissue, and this was followed by increasing hardening in the advanced stage as a result of porgressing fibrosis and calcification. Less