Experimental study of myocardial perfusion by myocardial contrast echocardiography with computer-aided technique / 中华超声影像学杂志

ABSTRACT

Objective To introduce a new computer-aided technique applicable for myocardial contrast echocardiography(MCE)to quantitate automatically calibrated myocardial contrast intensity(CI)and to test the value of color-coded images of calibrated CI in assessing myocardial perfusion.Methods There were two experimental groups of anesthetized rabbits,which underwent 30 min(group I)and 120 min(groupⅡ)coronary occlusion followed by 60 min reperfusion.MCE was performed on all rabbits during occlusion and after reperfusion,and its images were analyzed by a new computer-aided technique.Myocardial calibrated CI of each segment was measured and a color-coded map was produced automatically by software.The risk areas and infarct sizes obtained by myocardial perfusional defect(MPD)and color-coded map were compared with those by fluorescent microsphere and triphenyl-tetrazolium chloride(TTC)staining.Results Compared with non-risk segments,myocardial CI values were significantly decreased in risk segments in group Ⅰ and Ⅱ before calibration (P＜0.01),however,myocardial calibrated CI values were significantly decreased in risk segments in group Ⅱ(P＜0.01)and not different in group Ⅰ after calibration.Calibrated CI in-70 pix was an optimal cutoff point to identify infarcted segments and to yield the sensitivity of 95% and specificity 87%.The correlation between the risk area by MPD and fluorescent staining was 0.84(P=0.003)whereas color-coded map and staining was 0.91 (P＜0.001).The correlation between the infarct size by MPD and TTC was 0.75(P＜0.001),and between color-coded image and TTC was 0.89(P＜0.001).Conclusions MCE with a new computer-aided technique canassess quantitatively myocardial perfusion and identify automatically risk area and infarct region.