64层多排螺旋冠脉CTA与增强MRI延迟扫描对心肌梗死范围的比较

Comparative study of coronary CTA using 64 MSCT and delayed-enhanced MRI in evaluating the volume of myocardial infarction

目的:比较64层MSCT冠状动脉CTA检查时心肌低密度与增强MRI延迟强化对心肌梗死体积显示的差异。材料和方法:回顾性测量同时行64层MSCT和DE-MRI检查的心肌梗死患者23例。64层MSCT冠状动脉CTA图像进行左室短轴位图像重建,层厚8mm,层间隔8mm。测量每层短轴位图像上心肌低密度面积,将各层低密度面积累计积分得到体积。上述患者行DE-MRI延迟扫描,左室短轴位层厚为8mm,层间隔8mm,将各层中延迟强化心肌面积进行累计积分,得到MRI延迟强化测量的心肌梗死体积。将上述两种方法测量的体积进行配对t检验,以DE-MRI延迟强化得到的体积做为参考标准,比较MSCT通过心肌低密度判断心肌梗死的准确性。结果:64层MSCT冠状动脉CTA图像低密度与DE-MRI延迟强化测量得到的体积分别为(7.66±5.95)ml和(15.33±9.71)ml,P<0.01,二者相关系数为0.727。结论:通过64层MSCT冠状动脉CTA显示心肌低密度判断心肌梗死与DE-MRI有一定相关性,但会低估梗死的范围。

Objective： To assess myocardial hypo-enhancement in demonstrating the myocardial infarction （MI） in coronary artery CT angiography（CTA） performed by 64-MSCT and to compare the results with delayed-enhanced MRI（DE-MRI）. Materials and Methods： Twenty-three patients suspected of MI underwent both 64-MSCT and DE-MRI scanning. On 64-MSCT scanning, 60-85m1 iodine contrast medium（370mgI/ml） were injected and flushed with 40ml saline, injection velocity is 4-5ml/ s. The short axis of the left ventricle was reconstructed with 8mm slice thickness. On MRI scanning, contiguous left ventricular short-axis views were obtained 10 to 15min after the administration of gadopentetate dimeglumine 0.2mmol/kg. The hypoenhanced volume from CTA and delay-enhanced volume from DE-MRI were measured and compared. Results： The MI vol- ume measured by 64-MSCT and DE-MRI were （7.66±5.95）ml and （15.33±9.71）ml, respectively. The hypo-enhanced volume measured by 64-MSCT was correlated with that measured by DE-MRI （r=0.727）. Conclusions： The MI demonstrated as hypoenhanced region on CTA was underestimated compared to hyper-enhanced volume by DE-MRI.