运动校正技术在较快心率患者多排CT冠状动脉成像中的初步应用——与双扇区重建比较

Effect of A Novel Motion Correction Algorithm( SSF) on the Image Quality of Coronary CTA with Higher Heart Rates: Comparison with Bisector Reconstruction

目的 评价运动校正算法（SSF）消除较快心率患者多排CT冠状动脉成像运动伪影效果，并与双扇区重建（SSB2）进行比较。方法连续搜集于本院行冠状动脉CTA检查且扫描期间心率在65～75次／min之间的患者，采用GE宝石能谱CT进行回顾性心电门控扫描，并选取最佳重建时相分别进行SSB2和SSF下薄层图像重建。按照冠状动脉15段分段法，采用5分制评分法，分别对SSB2及SSF处理后的图像进行评分。冠状动脉段图像质量总体评分比较采用秩和检验，应用配对卡方检验比较不同图像质量评分在两组间的差异。结果共22例患者纳入研究，可评价冠状动脉共285段。不同图像质量评分等级在两组间差异有统计学意义（X^2=41．79，P=0．000），SSF组质量评分等级优于SSB2组。可评价的所有冠状动脉段图像质量评分平均秩次SSF组为314．01，SSB2组为256．99，两组间差异有统计学意义（Z=-4．443，P=0．000）。结论与SSB2相比，SSF技术能够在较快心率患者冠状动脉CTA成像中消除运动伪影，提高图像质量，具有较好的应用价值。

Objective To assess the effect of SSF algorithm on image quality in comparison with bisector reconstruction in higher heart rates. Methods Consecutive patients with mean heart rate （HR） range 65 -75 beats per minute（bpm） were performed retrospective ECG gated coronary CTA using a 64 row CT scanner （ GE Discovery CT750 HD）. The optimal SSF images were generated following the reconstruction protocol for SSF. Multiphase bisector images were reconstructed as well and the optimal phase was selected for comparison with SSF images. The images were interpreted by 2 experienced readers using a 5 point scale with 3 point as diagnostically acceptable. The image quality of coronary artery segments was compared in two groups using rank sum test , and the grade difference was compared using paired chisquare test. Results 22 patients were included in our study and a total of 285 coronary artery segments were evaluated. SSF provided significantly higher grade of coronary segments than that by bisector reconstructions （X^2 = 41.79 ,P = 0.000 ）. The mean ranks in image quality of coronary artery segments in group SSF was 198.77 ,whereas 162.23 in group SSB2. There was a statistical difference in image quality between the two groups （Z = -4. 443 ,P = 0. 000）. Conclusion SSF algorithm can provide superior image quality than bisector reconstruction in coronary CTA of patients with higher heart rates.