轻度缺血心肌的超声背向散射特性

超声背向散射积分是一项新的超声组织定征技术，为探讨该技术在冠心病研究方面的意义，本研究应用背向散射积分联机分析技术观测了１０例犬轻度缺血心肌不同时间点的散射特性。结果显示，同基础状态相比，在狭窄即刻缺血区域心肌的背向散射积分周期变异即开始减低，其中心内膜下心肌背向散射积分周期变异明显减低（Ｐ＜０．０５）；背向散射积分在狭窄即刻有增高趋势，但尚无统计学差异。再灌注后这些变化迅速恢复。散射特性的变化主要由心内膜下心肌散射特性的变化所致，心外膜下心肌的散射特性无明显变化。室壁增厚率在实验过程中无明显变化。结果说明超声背向散射积分联机分析简便、准确、可定量反映心肌病理结构和功能的细微改变，比室壁运动观察更客观、更敏感，可望为冠心病的早期诊断提供一个新方法

The Ultrasonic Backscatter Properties of Mild Ischemic Myocardium

The analysis of ultrasonic backscatter signals is a new tissue characterization method.Study of this technique aims to define the utility in coronary artery disease The calibrated integrated backscatter and the magnitude of cyclic variation of backscatter and wall thickening were measured with HP2500 LE in mild ischemic myocardium in 10 open chest dogs.The results showed,comparing with the bases,the CVIB of post wall decreased soon after the blood volume of circumflex coronary artery was decreased 40 45%(P<0 05);the IBS increased,but there was no statistic difference.These changes recovered rapidly soon!after reperfusion.The changes of backscatter properties of post wall were mainly caused by the changes of backscatter of subendocardial region.The IBS and CVIB of subepicardial regions exhibited no significant changes.There were no significant changes in wall thickening during the experiment.It was concluded that the on line analysis of integrated backscatter of myocardium is convenient and reliable, and can reflect quantitatively the mild changes of pathology and function of myocardium.Comparing with evaluating wall thickening,ultrasonic tissue characterization with integrated backscatter is more objective and more sensitive,provides a new method for early detecting coronary artery disease.