Study on intelligent optimum tube voltage scanning technique in abdomen CT 28-slices MSCT

Objective To investigate the effect of intelligent optimum tube voltage scanning(CARE kV) technique on the image quality and radiation dose of abdomen CT scan. Methods A total of 90 patients performed routine abdomen CT were enrolled,which included 50 males and 40 females, aged 46- 75 years with mean age of 61.6. The patients were randomly divided into 3 groups(30 of each): group A(tube voltage of 120 kV and 360 mA), group B( tube voltage of 120 kV and CARE Dose 4D technique), group C(tube voltage of CARE kV and CARE Dose 4D technique). The other scanning and image reconstruction parameters were identical,and the image quality was evaluated by 2 high qualification radiologists. The portal hepatic parenchyma CT value and image noise were measured, and the signal-to-noise ratio(SNR), contrast-noise ratio(CNR), average volume CT dose index(CTDIvol), product of dose length(DLP) and effective dose(ED) of the 3 groups were compared. Results The subjective scores of image quality of group A,B and C was 3.77, 3.50 and 3.60, respectively, and the difference was not statistically significant among 3 groups(P 0.05). The CNR of group A, B and C was 0.49, 0.38 and 0.50, respectively, and the SNR of group A, B and C was 3.53, 2.81 and 3.31,respectively. There was no statistically significant difference between group A and C(P 0.05), but there were statistically significant differences when compared group B with group A and C(P 0.05). The differences in CTDIvol and DLP among 3 groups were statistically significant(P 0.05). ED of group A, B and C was(13.25 ± 1.30) mSv,(7.57 ± 1.90) mSv and(6.36 ± 1.60) mSv,respectively, and the difference between any two groups was statistically significant(P 0.05). Conclusion It is demonstrated that in adult abdomen CT,CARE kV technique could select optimum scanning kV and mA automatically according to patients,which could reduce the overall radiation dose while maintaining image quality.