Performance of automatic tube voltage selection and sinogram-affirmed iterative reconstruction on the image quality and radiation dose in the enhanced dual-source abdominal CT

Abstract

Objective To investigate the impact of automatic tube voltage selection ( ATVS) and sinogram-affirmed iterative reconstruction ( SAFIRE) on image quality and radiation dose in the arterial phase (AP) and portal venous phase (PVP) abdominal dual-source CT imaging.Methods Abdomen contrast-enhanced computed tomography ( CECTs ) in 70 patients were scanned with dual-source CT.Patients were divided into study group and control group based on the scanning date.In the first 35 patients ( study group) , ATVS mode was applied; in the second 35 patients ( control group ) , the conventional fixed at 120 kVp mode was used.The imaging of the study group was reconstructed with FBP ( protocol A ) or SAFIRE ( protocol B ) respectively; the imaging of the control group was reconstructed with FBP ( protocol C).Image quality scores of the 3 protocols were assessed and compared with Rank-sum test.Analysis of variance was used to compare mean signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and image noise among the 3 protocols.Two sample t tests were used to compare the radiation dose difference.Results The effective radiation dose in the study group ( 3.9 ±0.4 ) mSv was much lower than that in the control group (4.9 ±0.4) mSv, dropped by 20.41% (t =2.315, P=0.021).The subjective rating scores in protocol A, B, C in arterial were (3.65 ±0.08), (4.41 ±0.10) and (3.79 ±0.10) point, while the subjective rating scores in venous phase were (3.57 ±0.08), (4.41 ±0.10) and (3.95 ±0.11) point.The differences were statistically significant (Z value were 27.587 and 27.436, P 0.05).Conclusion Use of ATVS and SAFIRE could reduce the radiation dose and provide better quality images compared with conventional abdominal CECT and FBP . Key words: Tomography,X-ray computed ; Radiation dosage ; Comparative study ; Image quality ;