Application of automatic tube voltage selection for abdominal CT in various patient sizes / 实用放射学杂志

ABSTRACT

Objective The purpose of this study was to evaluate the effect of patient’s body mass index on applications of auto-matic tube voltage selection (ATVS)for contrast-enhanced abdominal CT.Methods 1 60 patients underwent contrast-enhanced ab-dominal CT scan were assigned into the study group (ATVS technique)and the control group (120 kVp)with equal size (both n =80)according to the scanning mode.The two groups were both divided into four subgroups according to BMI (ABMI <18.5 kg/m2 ;BBMI 18.5~23.9 kg/m2 ;CBMI 24~28.9 kg/m2 ;DBMI ≥29 kg/m2 ).Image quality were assessed and compared with Rank-sum test.Analysis of variance was used to compare differences in mean contrast-to-noise ratio (CNR)and image noise a-mong the two groups.Two sample t tests were used to compare the radiation dose.Results In the study group,tube voltage of 100 kVp were selected highest(78.75%)and distributed from subgroups A to D,accounting for 60%,80%,90% and 60% respectively, with average BMI of (23.71±3.1 9)kg/m2 .Compared to control group,the effective dose of study group from subgroups A to C re-duced by 35.09%,27.61% and 1 9.08% respectively(t=3.829,4.389,2.238,P =0.005,<0.001,0.025).Despite the higher image noise in study group,the overall image quality was acceptable.Conclusion The contrast-enhanced abdominal CT with AVTS technique can reduce radiation dose in patients with BMI smaller than 28.9 kg/m2 .