Mottley J G, Glueck R M, Perez J E, Sobel B E, Miller J G
J Acoust Soc Am. 1984 Dec;76(6):1617-23. doi: 10.1121/1.391608.
Previous reports from our laboratory indicate that ultrasonic backscatter from myocardium exhibits a cyclic variation during the cardiac cycle that is reduced sharply by ischemia, a process which impairs both systolic contraction and diastolic relaxation. These results suggest that the cyclic variation of backscatter may be related to the cyclic variation of the contractile performance of the myocardium. Because contractile performance of the left ventricle is known to exhibit regional variability, the present study was undertaken to determine whether such regional differences in contractile performance are paralleled by differences in the magnitude of the cyclic variation of ultrasonic backscatter. Measurements obtained from representative zones of three regions of the hearts of ten open-chest dogs indicate that the magnitude of the cyclic pattern of variation of backscatter parallels the regional differences in contractile performance throughout the left ventricle with the maximum variation (5.5 +/- 0.9 dB peak-to-peak amplitude) occurring at the apex, intermediate values (4.3 +/- 0.8 dB) at the midwall, and minimum (0.5 +/- 1.0 dB) at the base. These results suggest that the ultrasonic backscatter may be sensitive to the regional myocardial contractile performance.
我们实验室之前的报告表明，心肌的超声背向散射在心动周期中呈现周期性变化，而缺血会使其急剧降低，缺血这一过程会损害心脏的收缩期收缩和舒张期舒张。这些结果表明，背向散射的周期性变化可能与心肌收缩性能的周期性变化有关。由于已知左心室的收缩性能存在区域差异，因此开展了本研究，以确定收缩性能的这种区域差异是否与超声背向散射周期性变化的幅度差异相对应。从十只开胸犬心脏三个区域的代表性区域获得的测量结果表明，背向散射变化的周期性模式幅度与整个左心室收缩性能的区域差异相对应，最大变化（峰峰值幅度为5.5±0.9 dB）出现在心尖，中间值（4.3±0.8 dB）出现在室壁中层，最小值（0.5±1.0 dB）出现在心底。这些结果表明，超声背向散射可能对区域心肌收缩性能敏感。
