Application values of fixed tube current based on head circumference in children's head CT examinations / 实用放射学杂志

ABSTRACT

Objective To explore the application values of fixed tube current based on head circumference(HC)in children's head CT examinations.Methods A total of 573 children's head CT imaging data were collected retrospectively,the tube current and HC were recorded.Pearson's correlation analysis was used to determine the relationship of tube current with HC,counted the median tube current values of each group based on HC and used them as the prefixed tube current.Seventy-two children were prospectively collected.According to the random number table method,the children were divided into the control group and the experimental group,with 35 cases in the control group and 37 cases in the experimental group.The control group used automatic exposure control(AEC)technology for tube current,while the experimental group used the median value of tube current corresponding to HC group-ing.The difference in radiation doses and image qualities between the two groups was compared.Results Pearson analysis of 573 retrospec-tive cases showed that the correlation between HC and tube current was considerably strong(r=0.95,P＜0.001).The median tube current values of each group based on HC were 70-130 mAs.There were statistically significant differences in CTDIvol.16 and SSDEDW based on water equivalent diameter(DW)between the two groups(t=-11.27,2.81,P＜0.05).Compared with the control group,CTDIvol.16 and SSDEDW in the experimental group decreased by 10.83％and 12.59％respectively.There were no statistically signifi-cant differences in signal-to-noise ratio(SNR)between the two groups(t=-1.26,P＞0.05)and there were also no statistically significant differences in the subjective evaluation of images(Z=-0.45,P＞0.05).Conclusion Measuring children's HC before examination and setting the fixed tube current corresponding to HC grouping can reduce radiation doses while maintaining image qualities.