声学密度定量技术评价梗死心肌的组织特征

Quantitative ultrasonic evaluation of infarcted myocardium using acoustic densitometry:comparing with radionuclide myocardial imaging

目的 探讨声学密度定量 (AD)技术评价梗死心肌组织特征的临床价值。方法 通过检测心肌背向散射积分参数并与放射性核素心肌显像及常规超声心动图进行比较 ,检测 42例各期前间壁心肌梗死患者的心肌及 2 0例对照者的正常心肌背向散射积分标化值 (IBS % )、背向散射积分周期变异幅度 (CVIB)、背向散射积分周期变异率 (CVIB % )、背向散射积分周期变异延迟率 (DTCV % ) ,同时测量舒张末期室间隔 /左室后壁厚度比值 (IVS/PW )、收缩期室壁增厚率 (ΔT % )及99m锝 甲氧基异丁基异腈 (MIBI)评分指数。结果 梗死心肌IBS %、DTCV %较正常心肌显著增高 (P <0 .0 0 1) ,而CVIB及CVIB %显著减低 (P <0 .0 0 1) ,CVIB及CVIB %与ΔT %及IVS/PW之间呈高度相关 (CVIB :r分别为 0 .75和 0 .6 3 ,P <0 .0 0 1;CVIB % :r分别为 0 .76和 0 .6 8,P <0 .0 0 1)。IBS %、CVIB、CVIB %与99m锝 MIBI评分指数之间呈较高的相关性 (r分别为 0 .5 8,-0 .6 8和 -0 .70 ,P<0 .0 1)。结论 声学密度定量技术能够敏感反映梗死心肌的组织学特征 。

Objective To quantitatively assess the histological characteristics of infarcted myocardium using acoustic densitometry(AD)and comparing with conventional radionuclide imaging and echocardiography. Methods Four integrated backscatter parameters were measured in 42 patients with recent or old anteroseptal myocardial infarction (group 1) and 20 normal persons (group 2). Calibrated myocardial integrated backscatter (IBS%), magnitude of cyclic variation in integrated backscatter(CVIB), the ratio of CVIB (CVIB%) and calibration of delayed time of CVIB (DTCV%) were detected. Meanwhile the ratio of septal to posterior wall thickness (IVS/PW), percent systolic wall thickening (ΔT%) and 99m TcMIBI uptaking fraction were measured.Results There were significant differences in IBS%, CVIB, CVIB% and DTCV% between group 1 and group 2, (P< 0.001 ).CVIB and CVIB% had also close correlation with ΔT% and IVS/PW (r= 0.75 , 0.63 , 0.76 , 0.68 ,respectively,P< 0.001 ). 99m TcMIBI uptaking fraction correlated significantly with IBS%,CVIB and CVIB%(r= 0.58 , -0.68 , -0.70 , respectively, P< 0.01 ).Conclusions Analysis of integrated backscatter parameters using acoustic densitometry can quatitatively assess the degree of myocardial fibrosis and viabilty.