多层螺旋CT和三维屏气MR冠状动脉成像的对比研究

目的比较16层螺旋CT（16 multi-detector CT,16-MDCT）冠状动脉血管造影（CTA）和三维屏气冠状动脉MR血管造影（MRA）的图像质量以及诊断冠状动脉显著性狭窄（＞50%）的准确性.方法40例疑有冠心病患者在3 d内均行冠状动脉CTA和MRA检查,其中31例患者在2周内行冠状动脉造影检查.将冠状动脉分成9个节段（右冠状动脉近、中、远段,左冠状动脉主干,前降支近、中、远段和旋支近、远段）,由2名影像科医生共同对各个节段的图像质量按0～4级评分,比较CTA和MRA上各个节段的图像质量.以冠状动脉造影为标准,计算并比较CTA和MRA诊断31例冠状动脉显著性狭窄（＞50%）各项准确性指标.结果CTA在右冠状动脉中段的图像质量低于MRA,右冠状动脉近段二者无区别,其他节段均优于MRA.冠状动脉造影显示31例患者共有43个节段狭窄＞50%,CTA和MRA分别正确诊断出36和27个,其敏感性、特异性、阳性预测值和阴性预测值分别为83%、84%、49%、97%和63%、90%、55%、93%.结论除右冠状动脉中段,CTA大部分节段的图像质量优于MRA.CTA诊断冠状动脉显著性狭窄的敏感性高于MRA,但特异性低于MRA.冠状动脉CTA和MRA均表现了较高的阴性预测值,对排除冠状动脉狭窄具有临床价值.

Comparative study of multi-detector CT and breathhold 3D MR coronary angiography in patients with coronary artery disease

Objective To compare multi-detector CT (MDCT) and MR coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant stenosis (> 50%) in patients with suspected coronary artery disease.Methods Both coronary MDCT angiography (CTA) and MR angiography (MRA) was performed within 3 days in 40 patients with suspected coronary artery disease, and conventional coronary angiography (CAG) was performed within 2 weeks after MDCT and MR scan in 31 patients. CTA was performed with a 16-MDCT scanner. MRA was performed on a 1.5 T MR scanner with breathhold 3D fast imaging employing steady state acquisition sequence. CTA and MRA image quality was evaluated in 9 coronarysegments by two experienced radiologists in concensus using a four-point grading scale. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for detection of significant stenosis on a segmental basis using CAG as reference and gold standard. Results MDCT showed higher image quality in most coronary segments except middle RCA (P<0.05). Significant stenosis was detected in 43 segments on CAG, 36 and 27 of the 43 segments were correctly diagnosed by CTA and MRA, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of CTA and MRA in detecting significant stenosis on a segmental basis were 83%, 84%, 49%, 97% and 63%, 90%, 55%, 93%, respectively. Conclusion Coronary CTA showed higher image quality in most coronary segments excepted for middle RCA. CTA had higher sensitivity for detection of coronary significant stenosis, whereas coronary MRA had higher specificity. Both CTA and MRA showed high negative predictive value, which is useful for excluding coronary stenosis in symptomatic patients.