The value of SAFIRE in coronary computed tomography angiography with low iodine intake and low radiation dose

Abstract：Objective To investigate the image quality and radiation dose of CT coronary angiography (CCTA) using snogram affirmed iterative reconstruction ( SAFIRE) with lower kVp and 25%iodine intake reduction compared with standard dose CTA u-sing filtered back-projection (FBP).Methods 58 patients were randomly divided into two groups (29 for each):Group A, 100 kVp, 210 mgI/kg, and reconstructed with SAFIRE;group B,120 kVp, 280 mgI/kg and reconstructed with FBP .The CT attenua-tion values of aortic root (AR), left main coronary artery (LMA), right main coronary artery (RMA) , left circumflex artery (LCX) and background noise were measured.The CT dose index-volume (CTDI), Signal-to-noise ratio (SNR), and contrast-to-noise ratio ( CNR) were measured and statistically analysed .Image quality was evaluated by two senior radiologists using a quali-tative five-point scale.Results Compared with group B, group A significantly reduced the iodine intake (A:15.0 ±1.54g, B:19.7 ±3.0g, P <0.01) and radiation dose of group A was reduced by about 48.5% ( A:6.45 ±1.07mSv, B:12.53 ±2.27 mSv, P <0.01).CT attenuation value ,SNR and CNR of all segments had no significant differences ( P >0.05).Subjective image quality of two groups had no significant differences ( P >0.05).Conclusion Using SAFIRE under the condition of lower kvp and 25%iodine reduction could obtain satisfactory images meeting the diagnostic requirements .