正弦图确定迭代重建在评价冠状动脉支架中的应用

Application of sinogram affirmed iterative reconstruction in evaluation of coronary artery stents

目的与传统滤波反投影(FBP)重建比较,评价Flash双源CT基于原始数据的正弦图确定迭代重建(SAFIRE)在冠状动脉支架中的应用价值。方法对54例患者冠状动脉支架术后行DSCT冠状动脉成像,比较FBP、SAFIRE(1～5)重建6组图像的平均CT值、SNR、支架内CT值净增比(SAIR)、图像质量主观评分、支架显示情况等。结果主动脉根部、支架内、支架上方冠状动脉的平均CT值差异均无统计学意义(P均>0.05)。SAIR、SNR差异有统计学意义(P均<0.05),FBP重建SAIR值最大,SAFIRE 3重建SAIR值最小;SAFIRE 3的SNR值最大。FBP与SAFIRE重建图像质量主观评分差异有统计学意义(P<0.05),SAFIRE 3主观评分最高[(3.24±0.57)分]。FBP与SAFIRE重建对于病灶的显示情况基本一致。结论与传统的FBP重建比较,SAFIRE重建可明显降低冠状动脉支架图像噪声,改善图像质量,更清晰显示支架内斑块。SAFIRE强度采用机器默认的重建强度3图像质量最佳。

Objective To assess the application value of sinogram affirmed iterative reconstruction （SAFIRE） in coronary artery stents with cardiac CT angiography by comparison with filtered back projection （FBP）. Methods Fifty-four patients with implanted stents underwent Flash CT, and six groups of images were reconstructed with FBP and SAFIRE （reconstruction strength 1-5）. The mean CT values, SNR, stent-lumen attenuation increase ratio （SAIR）, image quality scores and display of stents were compared. Results CT values of aortic root,in-stent, the coronary artery above stent had no significant difference （all P〈0. 05）. SAIR and SNR were statistically different （both P〈0. 05）. SAIR was the largest with FBP and the smallest with SAFIRE 3, while the largest SNR and the highest image quality （3.24~0.57） were obtained with SAFIRE 3. There was statistical difference in image quality scores between FBP and SAFIRE （P（0.05）. Display of lesion of FBP and SAFIRE were in general accord. Conclusion SAFIRE can significantly reduce SNR, improve imaging quality of coronary artery stents, and display plaque in the stent by Flash CT compared with FBP . Reconstruction strength 3 of SAFIRE may be recommended to reconstruct excellent images.