Sagar K B, Pelc L R, Rhyne T L, Howard J, Warltier D C
Department of Medicine, Medical College of Wisconsin, Milwaukee.
Circulation. 1991 Apr;83(4):1419-28. doi: 10.1161/01.cir.83.4.1419.
Ultrasonic tissue characterization (UTC) can distinguish normal from infarcted myocardium. Infarcted myocardium shows an increase in integrated backscatter and loss of cardiac cycle-dependent variation in backscatter. The cyclic variation of backscatter is closely related to regional myocardial contractile function; the latter is a marker of myocardial ischemia. The present study was designed to test the hypothesis that intramural cyclic variation of backscatter can map and estimate infarct size.
Transmural myocardial infarction was produced in 12 anesthetized, open-chest dogs by total occlusion of the left anterior descending coronary artery for 4 hours. A real-time ultrasonic tissue characterization instrument, which graphically displays integrated backscatter Rayleigh 5, cardiac cycle-dependent variation, and patterns of cyclic variation in backscatter, was used to map infarct size and area at risk of infarction. Staining with 2,3,4-triphenyltetrazolium chloride (TTC) and Patent Blue Dye was used to estimate infarct size and the area at risk, respectively. The ratio of infarct size to area at risk of infarction determined with UTC correlated well with that determined with TCC (r = 0.862, y = 23.7 +/- 0.792x). Correlation coefficients for infarct size and area at risk were also good (r = 0.736, y = 12.3 +/- 737x for infarct size and r = 0.714, y = 5.80 +/- 1.012x for area at risk). However, UTC underestimated both infarct size and area at risk.
Ultrasonic tissue characterization may provide a reliable, noninvasive method to estimate myocardial infarct size.
超声组织特征分析（UTC）可区分正常心肌和梗死心肌。梗死心肌表现为背向散射积分增加以及背向散射中与心动周期相关变化的丧失。背向散射的周期性变化与局部心肌收缩功能密切相关；后者是心肌缺血的一个标志。本研究旨在验证背向散射的壁内周期性变化能够描绘并估计梗死面积这一假说。
通过完全闭塞左前降支冠状动脉4小时，在12只麻醉开胸犬身上制造透壁性心肌梗死。使用一台实时超声组织特征分析仪器，该仪器以图形方式显示背向散射瑞利5积分、与心动周期相关的变化以及背向散射的周期性变化模式，来描绘梗死面积和梗死危险区。分别用2,3,4-三苯基氯化四氮唑（TTC）染色和专利蓝染料来估计梗死面积和梗死危险区。用UTC测定的梗死面积与梗死危险区面积之比与用TCC测定的结果相关性良好（r = 0.862，y = 23.7 +/- 0.792x）。梗死面积和梗死危险区的相关系数也较好（梗死面积r = 0.736，y = 12.3 +/- 737x；梗死危险区r = 0.714，y = 5.80 +/- 1.012x）。然而，UTC低估了梗死面积和梗死危险区。
超声组织特征分析可能提供一种可靠的、非侵入性的方法来估计心肌梗死面积。
