Objective        To investigate the difference of image quality between sinogram affirmed iterative reconstruction (SAFIRE) and filtered back projection (FBP) in coronary computed tomography angiography (CCTA)

and to evaluate the radiation dose in dual-source computed tomography (DSCT) using different tube voltages.       Materials        A Chinese

anthropomorphic chest phantom with simulated coronary arteries and thermoluminescent dosimeters (TLD) was given CCTA using different tube voltages (100 and 120 kV). The CCTA data sets of the two groups were reconstructed with SAFIRE and FBP. The CT value was measured

and the carrier noise ratio (CNR)

signal noise ratio (SNR) and standard deviation (SD) of CT value were calculated. The organic radiation doses were recorded and were converted into effective doses. The image quality of each group was compared by Dunnett t-test. The paired t-test was conducted to analyze the image quality at 120 kV/340 mA and 100 kV/340 mA.       Results      (1) The image quality of SAFIRE reconstruction was better than that of FBP reconstruction in different tube voltages. (2) The image quality tended to be improved along with the increase of tube current from 200 to 360 mA

and became stable when the tube current came to 340 mA or more. (3) In SAFIRE reconstruction

the SNR

CNR

and SD of CT value were statistically significant between the two groups (100 and 120 kV) (

P

0.05). (4) Both the effective doses and organic radiation doses increased along with the increase of scan parameters of CCTA from 80 to 120 kV.       Conclusion      The new reconstruction algorithm of SAFIRE can significantly improve the image quality under the same scan parameters. The effective doses and organic radiation doses increase along with the increase of CCTA tube voltage in an appropriate range.