双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

目的 与常规冠状动脉造影(CCA)对照,研究双源CT(DSCT)前瞻性心电门控序列扫描冠状动脉成像(SAS-CTCA)对冠状动脉狭窄诊断的准确性.方法 前瞻性的多中心研究,46例可疑冠心病患者[平均年龄(58±9)岁,体质量指数(BMI)(25±3)kg/m2]均进行了SAS-CTCA检查,并于14 d以内完成CCA检查.患者纳入标准:(1)心率控制在65次/min(bpm)以下;(2)窦性心律,心律规整,心率波动范围在6 bpm以内;(3)呼吸配合良好,屏气时间可达到12～15s.排除标准:(1)碘对比剂过敏、肝肾功能不全(血肌酐120 μmol/L)、心功能不全及严重心律不齐患者;(2)冠状动脉支架置入或冠状动脉搭桥患者;(3)心率快,而不能服用美托洛尔控制心率者;(4)不能服用硝酸甘油者;(5)体质量指数(body mass index,BMI)30 ks/m2 ;(6)其他心脏疾患:如心肌病、瓣膜病等.2名评价者分析SAS-CTCA及CCA的结果,计算SAS-CTCA对于冠状动脉狭窄诊断的敏感性、特异性、阳性预测值、阴性预测值,计算2名评价者间、两种检查方法之间的Kappa值,并对辐射剂量进行统计.结果 检查过程中患者的平均心率为(61±6)bpm,99.19%(614/619)的冠状动脉节段达到可供诊断的图像质量.与CCA相比,以冠状动脉血管为单位,SAS-CTCA在显示冠状动脉病变方面的敏感性、特异性、阳性预测值、阴性预测值分别为96.2%(75/78)、88.2%(60/68)、90.4%(75/83)、95.2%(60/63).两种检查方法之间的Kappa值为0.848(P=0.000).SAS-CTCA的平均有效剂量为(2.95±0.96)mSv.结论 在严格控制入选标准的前提下,SAS-CTCA检查可以在降低辐射剂量的同时获得满意的图像质量,并对诊断冠状动脉狭窄具有较高的可信性.

Multiple center study about the reliability of the low-dose dual-source CT coronary angiography in the step-and-shoot mode

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.