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

定量评价动脉硬化具有重要意义。本研究的目的是通过扫描声学显微镜测量超声衰减和传播速度来阐明动脉硬化活体组织的声学特征，并通过这些指标来评价动脉硬化的进展。我们用声学显微镜测量了超声在人冠状动脉内膜中的衰减和传播速度。我们使用超声组织表征系统与扫描声显微镜（HSAM-500S,450MHz）。52例患者的冠状动脉解剖标本，切成4微米厚。根据显微镜下内膜的病理表现，我们将其分为3组：正常（21例）、早期硬化（24例）和晚期硬化（7例）。年龄与超声衰减、年龄与传播速度之间的关系不具有统计学意义。超声衰减在早期（1.7(]SY.+-[)0.6dB）较低，在晚期（5.4(]SY.+-[)0.8dB）高于正常（2.5(]SY.+-[)0.5dB），传播速度在早期（1611.9(]SY.+-[)53.0m/s）较慢，在晚期（2031.4(]SY.+-[)145.0m/s）较正常（1757.8(]SY.+-[)90.4）较快。综上所述，超声衰减和传播速度均不受年龄的影响，而主要受病理性动脉粥样硬化改变的影响。此外，与冠状动脉的光学表现相比，这两个参数均呈非线性变化。由于传播速度与体积模量的平方根成正比，因此在较硬的组织中传播速度更快。因此，我们得出结论，与正常组织相比，冠状动脉内膜在光学定义的疾病早期阶段表现出最初的软化，随后在晚期由于纤维化和钙化的进展而增加硬化。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