冠状动脉狭窄的电子束CT诊断

目的：评价电子束CT(EBCT)及其三维血管成像对冠状动脉狭窄诊断的准确性及局限性。方法：37例经EBCT冠状动脉增强扫描和三维重建的患者，均又经常规心血管造影检查(CAG)。由两名不知其它检查结果的放射科医师将冠状动脉左主干(LM)和左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA)的近、中段评价后与造影结果逐段对照．并作统计学分析。结果：在CAG结果≥2mm的219个冠状动脉节段中，EBCT可评价的有228(91.6％)个，无法评价的21(8．1％)个，影响因素最主要为广泛钙化遮蔽管腔。EBCT诊断冠状动脉各主干近、中段≥50％狭窄总的敏感性、特异性和阳性预测值、阴性预测值分别为80．1％、91．3％、72．4％、92．5％。其中左主干均为100％．前降支分别为90．4％、94．2％、84．5％和96．1％。结论：EBCT是较好的无创性冠状动脉成像技术，对冠状动脉左主干和前降支近、中段狭窄的评价具有极高的准确性．虽然无法替代CAG，但极具临床应用潜力。局限性是空间分辨率低，价格昂贵。

Electron beam computed tomographic coronary angiography for evaluation of coronary artery stenosis

Objective:To evaluate the accuracy of electron beam computed tomographic angiography (EBA) with three dimensional reconstruction in diagnosing stenosis of coronary artery.Methods:37 patients underwent both EBA and conventional coronary angiography (CAG).EBA three dimensional images were analyzed by two observers blinded to the results of CAG,and all data were statistically analyzed.Results:Of a total of 249 coronary artery segments >2mm in CAG,228 (91.6%) were analyzable and 21(8.4%) were unevaluable in EBT images.The chief reasons of unevaluability were extensive calcification covering lumen of vessels.Overall sensitivity,specificity and positive and negative predictive value to detect a >50% diameter stenosis were 80.1%,91.3%,72.4%,92.5% respectively.These in left main coronary artery (LM) were all 100% and in left anterior desending coronary artery (LAD) were 90.4%,94.2%,84.5% and 96.1%.Conclusion:EBA is a promising non invasive coronary artey imaging technique.It is accurate for detecting and ruling out significant stenosis in proximal and middle segments of the main vessels of coronary artery,especially in LM and LAD.At present time,EBCT has clinical applicational potential although can not replace invasive CAG.The limitation of EBCT is low spatial resolution and expensive cost.