心肌背向散射组织定征技术在冠状动脉旁路移植术前后的应用

Study of Ultrasonic Tissue Characterization with Integrated Backscatter of Myocardium in Coronary Artery Bypass Grafting

目的 研究冠状动脉旁路移植术 (CABG)前后心肌背向散射 (IBS)参数的变化 ,评价心肌背向散射组织定征技术 (MUTC)在CABG中的应用价值。方法 对 3 2例冠状动脉左前降支病变并且行左前降支架桥术的病人 ,于术前、术后 2～ 6周、3个月、半年分别行超声心动图检查。观测指标包括 :M -mode定量左室前壁的运动幅度及室壁增厚率 ,显示AD状态下心肌的背向散射图像 ,分析缺血心肌和非缺血心肌 ,缺血心肌手术前后的背向散射积分 (AII)、周期性变化曲线的幅度 (CVIB)和形态 (IB曲线形态评分 )的变化。结果 术前缺血心肌较非缺血区心肌的IBS %值升高、CVIB值降低 ,IB曲线形态评分升高。术后室壁运动恢复节段与无室壁运动恢复节段相比 ,其术前的CVIB值高、IB曲线形态评分低 ,两者呈显著性差异。缺血心肌术后IBS %值降低、CVIB值增高 ,IB曲线形态评分降低 ,这种变化以术后 3月最为明显。结论 冠状动脉旁路移植术后心肌背向散射参数有明显改变 ,MUTC技术所测定的IBS参数能相对客观的预测、评价手术疗效。

Objective To study ultrasonic tissue characterization with integrated backscatter of myocardium in coronary artery bypass grafting (CABG). Methods 32 patients with stenosis of left anterior descending coronary (LAD) branch and undergoing LAD CABG were enrolled in this study. Echocardiographic examinations were performed before and after CABG (4 times follow-up, 2-6 weeks, 3 months, 6 months and 1 year) to obtain the 2-D and M-mode images for measuring motion and percent wall thickening of left ventricular anterior wall. The backscatter images were collected in the integrated backscatter mode for off-line analysis. The calibrated average value of IB, the patterns of IB curves and the magnitude of the cyclic variation of integrated backscatter (CVIB) we remeasured. Results Before operation, the IBS% of left ventricular anterior wall with coronary stenosis were higher than the wall without coronary stenosis and the CVIB lower. The CVIB and the pattern of IBS in the zone with wall motion restoration after operation were significantly different from that with non-restoration. After operation the IBS% reduced, CVIB increased and the pattern of IBS reduced in ischemia myocardium respectively. Conclusion The parameters of IBS changed significantly after CABG. The effect of CABG could be predicted and evaluated by the parameters of IBS from MUTC.