多层螺旋CT诊断冠状动脉狭窄的价值和限度

Value and limitations of multislice spiral CT in diagnosing coronary artery stenoses

目的评价多层螺旋CT（MSCT）在冠状动脉狭窄诊断中的价值和限度。方法临床诊断或可疑冠心病的65例患者接受冠状动脉MSCT检查，采用回顾性心电门控、0．5s／转的螺旋扫描、单扇区重建算法和静脉注射对比剂，其检查结果与导管法冠状动脉造影进行对照。结果在65例患者的冠状动脉889节段（直径≥1．5mm）中，CT图像满足管腔评价为795节段（占89．4％）。对于CT图像满足管腔评价的冠状动脉节段，MSCT对冠状动脉中度和中度以上狭窄（I〉50％）诊断的敏感度和特异度分别为88．6％和95．1％，阳性预测值和阴性预测值分别为82．7％和96．9％；MSCT显示冠状动脉高度狭窄（／〉75％）的敏感度和特异度分别为90．7％和97．6％，阳性预测值和阴性预测值分别为82．1％和98．9％。结论如果冠状动脉CT图像满足管腔评价，MSCT对冠状动脉狭窄的诊断准确性很高。MSCT可用于冠状动脉狭窄的初步诊断和介入治疗的筛选。

Objective To evaluate the value and limitations of multislice spiral CT in diagnosing coronary artery stenoses. Methods A total of 65 patients with known or suspected coronary artery disease were examined by multislice spiral CT （retrospectively ECG-gating; 0. 5 s rotation; one-sector reconstruction algorithm; intravenous contrast agent ） and the results were compared with quantitative coronary angiography. Results In the 889 coronary artery segments of 65 patients, 795 could be evaluated by CT （89.4%）, 148 out of 167 coronary artery segments with significant stenoses （≥50% reduction of vessel diameter） were correctly detected by CT, 597 out of 628 coronary artery segments with normal or mild stenosis （ 〈 50% reduction of vessel diameter） were correctly detected by CT. These values correspond to a sensitivity of 88.6%, specificity of 95.1%, positive predictive value of 82. 7%, and negative predictive value of 96. 9% for the detection of significant coronary artery stenosis by CT. Adding the 23 coronary artery segments with significant stenosis which could not be judged by CT, the sensitivity of CT for diagnosing coronary stenosis was 77.9%. In the 795 evaluable coronary artery segments, 78 out of 86 coronary artery segments with high-grade stenosis （≥75% reduction of vessel diameter） were correctly detected by CT, 692 of 709 coronary artery segments with normal or mild stenosed （ 〈 75% reduction of vessel diameter） were correctly detected by CT. These values correspond to a sensitivity of 90.7%, specificity of 97. 6%, positive predictive value of 82. 1%, and negative predictive value of 98. 9% for the detection of high-grade coronary artery segments stenosis by CT. Adding 13 coronary artery segments with high-grade stenosis which could not be judged by CT, the sensitivity was 78.8%. Conclusion Multislice spiral CT permits the visualization of significant coronary artery stenosis with high accuracy in case of sufficient image quality.