迭代重建在双源CT冠状动脉成像中的应用

目的与滤过反投影法(FBP)对比,评价迭代重建(IR)在双源CT(DSCT)冠状动脉成像中对图像质量的影响。方法对57例患者进行DSCT冠状动脉成像检查,分别采用常规FBP法和IR法对最佳期相图像进行重建。对图像质量进行主观评价,测量两种重建方法所得冠状动脉图像的CT值、噪声、SNR及CNR。结果 57例患者冠状动脉图像质量评分中,IR图像质量为优的血管段比例为83.18%(628/755),高于FBP重建图像(595/755,78.81%,P=0.030)。FBP重建与IR图像强化水平(CT值)分别为(311.49±63.76)HU、(310.57±64.45)HU(P=0.280),图像噪声分别为(19.58±3.47)HU、(13.11±3.06)HU(P<0.001),SNR分别为16.27±3.89、24.48±5.73(P<0.001),CNR分别为20.63±4.24、30.84±7.24(P<0.001)。结论 DSCT冠状动脉成像中应用IR法可在保证冠状动脉腔内强化程度不变的同时明显降低图像噪声,改善图像质量。

Application of iterative reconstruction in coronary dual-source CT angiography

Objective To investigate the effects of iterative reconstruction (IR) on image quality in coronary dual-source CT (DSCT) angiography comparing with regular filtered back projection (FBP). Methods Fifty-seven patients underwent DSCT examination. Images in the best reconstruction intervals were reconstructed with regular FBP and IR technique. Subjective assessment on image quality was performed, CT value, noise, SNR and CNR were measured and compared between FBP and IR. Results In 57 patients, the ratio of good image quality was 78.81% (595/755) for FBP and 83.18% (628/755) for IR (P=0.030). The contrast enhancement (CT value) were (311.49±63.76)HU and (310.57±64.45)HU (P=0.280). The image noise was (19.58±3.47)HU and (13.11±3.06)HU (P<0.001). SNR was 16.27±3.89 and 24.48±5.73 (P<0.001), and CNR was 20.63±4.24 and 30.84±7.24 (P<0.001). Conclusion Compared with regular FBP, IR enables significant reduction of image noise and improves image quality in coronary DSCT angiography.