实时心肌造影超声心动图对心肌灌注跨壁分布的实验研究  

Assessment of transmural distribution of myocardial perfusion by real-time myocardial contrast echocardiography

作　　者：姚桂华[1] 张运[1] 张梅[1] 赵静[1] 季晓平[1] 仲琳[1] 丁士芳[1] 王燕[1] 陈文强[1] 苗雅[1] 

机构地区：[1]山东大学齐鲁医院心内科,济南250012

出　　处：《中华超声影像学杂志》2004年第11期853-856,共4页Chinese Journal of Ultrasonography

基　　金：国家自然科学基金资助项目(60072022)

摘　　要：目的　探讨实时心肌造影超声心动图(MCE)评价心肌灌注跨壁分布的可行性。方法　健康 犬6只,建立冠状动脉前降支(LAD)分级狭窄动物模型,以超声血流计检测LAD血流量。采用低发射功 率的实时MCE技术和持续静脉注射造影剂(SonoVue)的方法,分别在基础、双嘧达莫诱发充血、LAD不同 程度狭窄、再灌注及完全结扎状态下进行MCE检查。分别将感兴趣区(ROI)置于心内膜层与心外膜层得 出信号强度 时间曲线,并与指数函数拟合得出A、β、A·β测值,进而计算出各项测值的跨壁梯度,即心 内 外膜层A比值(A EER)、心内 外膜层β比值(β EER)和心内 外膜层A·β比值(A·β EER)。结果 基础状态、充血状态及LAD血流量减少50%时,A、β以及A·β测值在心内、外膜层分布差异无显著性意 义(P>0.05),跨壁梯度接近1;LAD血流量减少75%时,心内膜层β与A·β测值明显低于心外膜层测 值,β EER、A·β EER降低(P均<0.01);减少90%时,心内、外膜层A、β及A·β均明显降低,但心内 膜层测值低于心外膜层测值,A EER、β EER、A·β EER明显降低(P均<0.01);再灌注10min后,A、β 及A·β测值恢复至基础水平(P>0.05),A EER、β EER、A·β EER接近1;完全结扎LAD90min后, 心内、外膜层各测值再次降低(P均<0.01)。Objective To explore the practicability of real-time myocardial contrast echocardiography (MCE) in assessing the transmural distribution of myocardial perfusion. Methods Three grades of left anterior descending coronary artery(LAD) stenoses were created in 6 open-chest dogs. Stenoses reduced LAD flow by 50%, 75% and 90% of hyperemia guided by flow probe. Low-energy MCE were performed at baseline, hyperemia reduced by dipyridamole, three different stenoses, reperfusion and complete occlusion, respectively, during continuously infusion of SonoVue. Regions of interest(ROI) were placed individually within endocardial and epicardial layers and myocardial signal intensity-versus-time plots just after high-energy FLASH frames were fitted to an exponential function to obtain values of A, β, A·β. The corresponding transmural gradients, defined as endocardial-epicardial ratios of A (A-EER),β(β-EER) and A·β(A·β-EER) were also calculated. Results The transmural distributions of A,β and A·β were more or less homogeneous at baseline,hyperemia and 50% reduced LAD flow, with their transmural gradients near 1. When LAD flow was reduced by 75%,β and A·β from endocardial layer decreased (P< 0.01), and β-EER,A·β-EER decreased accordingly (P< 0.01). At 90% reduced LAD flow, A, β and A·β from both endocardial and epicardial layers all decreased, and A-EER,β-EER and A·β-EER declined also (all P< 0.01). All values returned nearly to prestenosis level at reperfusion for 10 minutes. Whereas, all of these values declined again significantly when LAD was completely occluded for 90 minutes (all P< 0.01). Conclusions Real-time MCE with low-energy has a potential in assessing the transmural distribution of myocardial perfusion and can identify the severity of coronary stenosis.

关 键 词：心肌造影 超声心动图 心肌灌注 心肌缺血 造影剂 MCE 

分 类 号：R445.1[医药卫生—影像医学与核医学]