腔内CT密度值用于评估冠状动脉钙化及狭窄程度

Intraluminal CT values for evaluating stenosis of calcified coronary artery

目的观察冠状动脉CT成像(CCTA)中,根据冠状动脉钙化(CAC)近端与远端冠状动脉管腔CT值及校正后冠状动脉强化值(CCO)差值评估钙化部位管腔狭窄的准确度。方法对CCTA显示钙化的233支主要冠状动脉(左前降支、左回旋支和右冠状动脉),根据狭窄程度分为轻度狭窄组、中度狭窄组、重度狭窄组和完全闭塞组,比较各组CCO差值,分析以钙化近远端CCO差值评估冠状动脉狭窄的准确度。结果完全闭塞组CCO差值高于轻度狭窄组、中度狭窄组和重度狭窄组(P<0.001);重度狭窄组与中度狭窄组CCO差值差异无统计学意义(P>0.05);中度狭窄组和重度狭窄组CCO差值高于轻度狭窄组(P<0.001)。以钙化近远侧CCO差值0.0869作为诊断界点,其诊断冠状动脉≥50%狭窄的敏感度、特异度、阳性预测值和阴性预测值分别为76.67%、75.47%、91.39%和48.78%;以0.2070作为诊断界点时,其诊断冠状动脉闭塞的敏感度、特异度、阳性预测值和阴性预测值分别为91.84%、79.89%、54.88%和97.35%。结论冠状动脉钙化近远端管腔CCO差值随狭窄程度加重而升高,以之作为评价指标,可明显提高评估冠状动脉钙化及狭窄程度的准确性。

Objective To observe the accuracy of intraluminal CT values of coronary artery across calcification and the corrected coronary opacification(CCO)difference in evaluation on stenosis severity of coronary artery during computed tomography angiography(CCTA).Methods Coronary artery calcifications(CAC)were detected in 233 main branches of coronary arteries(left anterior descending artery,left circumflex artery and right coronary artery)with CCTA.According to the degree of stenosis,the vessels were divided into mild stenosis group,moderate stenosis group,severe stenosis group and total occlusion group,respectively.The accuracy of CCO difference for evaluating coronary stenosis were analyzed and compared among groups.Results CCO difference across calcification was significantly higher in total-occlusion group than in the other 3 groups(P<0.001),but not significantly different between severe stenosis group and moderate stenosis group(P>0.05),while were higher in severe stenosis group and moderate stenosis group than in mild stenosis(P<0.001).Taken 0.0869 as the cut-off point of CCO difference across calcified coronary artery,the sensitivity,specificity,positive predictive value and negative predictive value was 76.67%,75.47%,91.39%and 48.78%for diagnosing coronary artery stenosis≥50%,respectively,while taken 0.2070 as the cut-off point,the sensitivity,specificity,positive predictive value and negative predictive value was 91.84%,79.89%,54.88%and 97.35%,respectively for diagnosing total-occlusion of coronary artery.Conclusion CCO difference across calcified coronary artery elevated as stenosis severity increased.Taking CCO difference across calcified coronary artery as an index might improve the accuracy of evaluating coronary artery calcification and stenosis.