DECT诊断冠状动脉狭窄及缺血性心肌价值

Diagnostic value of dual-energy CT(DECT) to coronary artery stenosis and ischemic cardiomyopathy

目的 利用受试者工作特征曲线（ROC）评价双源CT（dual energy CT，DECT）诊断冠状动脉狭窄及缺血性心肌的价值。方法 回顾性分析2011年1月~2013年10月新乡市中心医院就诊疑似冠心病（CHD）的患者70例，先后接受DECT和冠状动脉造影术（CAG）检查；其中40例患者在DECT检查后2周内行99mTc-MIBI单光子发射型计算机扫描（SPECT）运动-静息心肌灌注显像（MPI）；70例患者中男性48例，女性22例，年龄51~78岁，平均（61.8±7.2）岁。以CAG（狭窄≥50%、≥75%）和SPECTMPI结果为“金标准”，计算DECT诊断冠状动脉狭窄和缺血性心肌的敏感度、特异度、阳性预测值、阴性预测值和正确指数。结果 ①当CAG检查结果冠状动脉内径狭窄≥50%、≥75%时，DECT诊断冠状动脉狭窄的灵敏度为74.19%（92/124）、81.52%（75/92），特异度为90.26%（139/154）、93.01%（173/186），阳性预测值为85.98%（92/107）、85.22%（75/88），阴性预测值为81.29%（139/171）、91.05%（173/190），正确指数83.09%（231/278）、89.21%（248/278）。ROC曲线下面积（AUC）及Z检验 0.82、0.87，Z=13.96、16.64，P均＜0.001。②DECT碘图与SPECT MPI结果对比，DECT诊断缺血性心肌的灵敏度为90.00%，特异度为80.00%，阳性预测值为49.09%，阴性预测值为97.39%，正确指数为81.76%，AUC=0.823，Z=18.722，P＜0.001。结论 DECT诊断冠状动脉狭窄及缺血性心肌具有较高效能，能为临床诊治提供有效的影像学依据。

Objective To review the value of dual-energy CT (DECT) to coronary artery stenosis and ischemiccardiomyopathy by using receiver operating characteristic curve (ROC). Methods CHD patients (n=70, male 48,female 22, aged from 51 to 78 and average age=61.8±7.2) were chosen from Jan. 2011 and Oct. 2013. The patientsaccepted successively DECT and coronary angiography (CAG), and 40 of 70 patients were given SPECT stress-restmyocardial perfusion imaging (MPI) 2 w after DECT. The outcomes of CAG (stenosis≥50% and stenosis≥75%) weretaken as gold standard, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) andcorrect index of DECT in diagnosis of coronary artery stenosis and ischemic cardiomyopathy were calculated. Results①When the outcome of CAG were stenosis≥50% and stenosis≥75%, the sensitivity of DECT in diagnosis of coronaryartery stenosis was, respectively, 74.19% (92/124) and 81.52% (75/92), specificity was 90.26% (139/154) and 93.01%(173/186), PPV was 85.98% (92/107) and 85.22% (75/88), NPV was 81.29% (139/171) and 91.05% (173/190), andcorrect index was 83.09% (231/278) and 89.21% (248/278). The area under curve (AUC) of ROC was, respectively,0.82 and 0.87, and Z=13.96 and Z=16.64 (All P<0.001). ②The comparison in outcomes of DECT and SPECT MPIshowed that the sensitivity of DECT in diagnosis of ischemic cardiomyopathy was 90.00%, specificity was 80.00%,PPV was 49.09%, NPV was 97.39%, correct index was 81.76%, AUC=0.823 and Z=18.722 (P<0.001). ConclusionDECT has higher accuracy in diagnosis of coronary artery stenosis and ischemic cardiomyopathy, and can provideeffective imaging evidence for clinical treatment.