Sehgal C M, Brown G M, Bahn R C, Greenleaf J F
Ultrasound Med Biol. 1986 Nov;12(11):865-74. doi: 10.1016/0301-5629(86)90004-9.
The acoustic nonlinearity parameter B/A and sound speed c have been determined for excised normal and abnormal human livers at 20-37 degrees C. These values are compared with analytic measurements of fat and water content of tissues. The results show that normal liver containing 71.0% water and 2.9% fat by weight has a B/A value of 6.75 and sound speed of 1592 m/s at 37 degrees C. Both these parameters increase at an average rate of 0.026 degrees C and 1.5 m/s/degrees C, respectively, as the temperature is raised from 20 to 37 degrees C. Fatty liver (24% fat by weight) exhibits highest B/A (9.12) and lowest c (1522 m/s) of all the livers studied. In contrast to normal livers sound speed in such a liver was found to decrease with temperature. Based on the acoustic and composition measurements, quantitative correlations of B/A and c with fat-water composition have been developed. Inversion of these relationships provide a simple method to determine composition of a tissue sample from B/A and c measurements.
已在20至37摄氏度的温度范围内，对切除的正常和异常人体肝脏测定了声学非线性参数B/A和声速c。将这些值与组织中脂肪和水分含量的分析测量结果进行了比较。结果表明，按重量计含有71.0%水和2.9%脂肪的正常肝脏，在37摄氏度时的B/A值为6.75，声速为1592米/秒。随着温度从20摄氏度升高到37摄氏度，这两个参数分别以平均0.026/摄氏度和1.5米/秒/摄氏度的速率增加。在所有研究的肝脏中，脂肪肝（按重量计含24%脂肪）的B/A值最高（9.12），声速最低（1522米/秒）。与正常肝脏不同，在这样的肝脏中发现声速随温度降低。基于声学和成分测量，已建立了B/A和声速与脂肪-水成分的定量相关性。这些关系的反演提供了一种从B/A和声速测量中确定组织样本成分的简单方法。
