迭代重建不同参数对双源CT冠状动脉图像质量的影响

Effects of Iterative Reconstruction Technique on Image Quality in Cardiac CT Angiography

目的:探讨迭代重建(SAFIRE)不同参数与滤过反投影法(FBP)相比,对双源CT(DSCT)冠状动脉成像中图像质量的影响。方法:随机对30例行DSCT冠状动脉成像的患者,分别采用FBP和SAFIRE不同参数(参数分为1级、2级、3级、4、级、5级)的最佳期相进行重建,分为6组,分别测量其主动脉根、左主干、左前降支、回旋支、右冠的CT值、噪声、信噪比(SNR)、对比噪声比(CNR),客观评价其图像质量。结果:6组各位置测量的CT值对比,差异无统计学意义(P>0.05),噪声、SNR、CNR差异有统计学意义(P<0.05)。各组之间多重对比图像质量SAFIRE 1级<SAFIRE 2级<FBP<SAFIRE 3级<SAFIRE 4级<SAFIRE 5级。结论:在DSCT冠状动脉成像技术中,迭代重建技术参数SAFIRE 3、4、5级能在保持冠状动脉强化CT值不变的情况下,降低图像噪声,提高图像质量。

Objective：We attempted to compare image quality parameters of iterative reconstruction and conventional filtered back-projection（FBP）quantitatively in cardiac CT angiography,using dual-source CT technology.Methods：Thirty patients were scanned using dual-source CT for assessment of native coronary artery disease.Multiphase datasets were reconstructed using FBP and iterative reconstruction techniques.CT value,image noise and signal to noise ratio（SNR）were measured.Contrast-to-noise ratios（CNR）were compared at 5specific coronary artery locations.Results：In all evaluated coronary artery locations,the imgaing noise,SNR and CNR were significantly improved with iterative reconstruction when compared to conventional FBP.Iterative reconstruction demonstrated less image noise across all cardiac phases.Conclusion：Iterative reconstruction offers the potential to increase CNR in cardiac CTA.Our experience suggests that iterative reconstruction algorithms have the potential tomaitain similar objective image quality measures such as CNR and noise levels versus standard FBP reconstructions.