心率对64层螺旋CT冠状动脉成像图像质量的影响

目的:评价心率对64层螺旋CT冠状动脉成像图像质量的影响.方法:采用GE Light speed 64层螺旋VCT,以心脏扫描模式对心脏动态体模进行扫描.心脏动态体模由3个部分组成:动力部分、解剖结构模拟部分和控制部分.心脏动态体模的心率设置为40、45、50、55、60、65、70、75、80、85、90、95、100、105、110和115次/min,心律齐.以球管转速0.35 s对不同心率下的心脏动态体模进行冠状动脉成像扫描.所有扫描数据在R-R间期90%时相分别进行单扇区和多扇区重建.重建数据传至工作站后处理成像.后处理方法采用VR、MPR重组模式.分别对重建图像进行评分.结果:①心率与图像质量呈负相关(P＜0.01);随着心率的增加,图像质量评分呈下降趋势;②在同一条件下多扇区重建算法较单扇区重建算法提高了图像质量评分.结论:采用心脏动态体模评价心率对64层螺旋CT冠状动脉成像图像质量的影响,对临床研究和应用有着重要价值.

Experimental Study of the Effect of Heart Rate on the Image Quality of Coronary Artery with 64-detector Row Helical CT Using a Pulsating Cardiac Phantom

Objective:Using a pulsating cardiac phantom to study the effect of heart rate on the image quality of coronary artery with 64-detector row helical CT.Methods:An adjustable pulsating cardiac phantom (GE) containing predetermined simulated coronary arteries was scanned using 64-detector row helical CT with cardiac pulsating rates as 40,45,50,55,60,65,70,75,80,85,90,95,100,105,110 and 115 beats per minute (bpm).The rotation speed of 0.35s was used.The raw data were reconstructed at an optimal window of the R-R interval using both one sector and multi-sector and volume rendering (VR) and multi-planar reformation (MPR) as the reconstruction algorithm.The image quality score (IQS) was evaluated by two radiologists respectively.Results:There was negative correlation between heart rate and IQS (P<0.01).The image quality of multi-sector reconstruction algorithm was superior than that of one-sector.Conclusion:Using a pulsating cardiac phantom,with 64-detector row CT,the effect of heart rate on the image quality of coronary artery could be evaluated,which plays an important role in clinical research as well as clinical application.