背向散射积分超声组织定征识别存活心肌的实验

目的探讨背向散射积分检测技术识别存活心肌的敏感性和准确性。方法应用商品化的背向散射积分联机分析处理系统检测活体开胸犬重度缺血、晕厥和梗死心肌模型的标化背向散射积分（ＩＢＳ）、标化背向散射积分周期变异（ＣＶＩＢ）及室壁增厚率。结果重度缺血心肌ＩＢＳ明显增高，ＣＶＩＢ明显减低。再灌注后ＣＶＩＢ的恢复幅度高于室壁增厚率。晕厥心肌的ＩＢＳ和ＣＶＩＢ基本正常，但室壁增厚率明显减低。梗死心肌的ＩＢＳ明显增高，ＣＶＩＢ消失或呈反相，再灌注后无改善。结论背向散射积分超声组织定征能敏感反映不同程度缺血心肌的散射特性变化，为无创判定心肌存活性和评价心肌功能提供了一个新的技术手段

Detection of viable myocardium by ultrasonic tissue characterization with integrated backscatter

Objective\ To assess the utility of ultrasonic tissue characterization with integrated backscatter (IBS) on detection of viable myocardium. Methods\ Online analysis of IBS was carried with a commercially available system in severe ischemic, stunned and infarcted myocardium of anesthetized open chest dogs (severe ischemia n=8, stunned n=6, infarcted n=6). Results\ In severe ischemic myocardium, the calibrated IBS increased significantly, the calibrated CVIB decreased significantly, CVIB curve presented a lower amplitude. After reperfusion, the recovery of CVIB prior to wall thickening. The stunned myocardium showed normal IBS and CVIB, though wall thickening decreased significantly. The calibrated IBS of infarcted myocardium increased significantly, the calibrated CVIB decreased significantly, CVIB curve became straight or inverse phase. CVIB showed no recovery after reperfusion. Conclusions\ Online analysis of IBS can sensitively detect viable myocardium. This approach may provide a new noninvasive tool for assessment of myocardial viability and function.