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 / 中华放射学杂志

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, P0.05).Conclusion Use of ATVS and SAFIRE could reduce the radiation dose and provide better quality images compared with conventional abdominal CECT and FBP .