An applied study of a personalized adult chest low-dose CT scanning protocol based on body mass index-adjusted tube current

HUANG Yuanbin; WEI Bo; ZHAO Zhenxiang; LONG Xizhen; LIANG Jing

Abstract：Objective:To explore the application effect of personalized low-dose CT scanning scheme for adult chest based on body mass index(BMI)regulation tube current.Methods:A total of 160 adult patients who underwent chest CT examination in hospital from January 2023 to December 2023 were selected as the study subjects.They were ran-domly divided into a conventional dose group and a low-dose group using a random number table method,with 80 cases in each group.Record the gender and age of two groups of patients,measure their height and weight,and calculate their BMI.The conventional dose group is set with a tube voltage of 110 kV and a fixed tube current of 150 mA.The low-dose group was set with a tube voltage of 110 kV,and the tube current was set based on the patient's BMI(high body mass index group:BMI＞24 kg/m2,tube current 50 mA;medium body mass index group:19 kg/m2≤BMI≤24 kg/m2,tube current 40 mA;low body mass index group:BMI＜19 kg/m2,tube current 30 mA).Two radiologists with interme-diate professional titles or above were responsible for evaluating the quality of chest CT images.The patients'general data,image quality evaluation results and radiation dose data were analyzed statistically.Results:There was no statisti-cally significant difference(P＞0.05)in the clinical data of gender,age,weight,height,and BMI between the two groups of patients.The subjective evaluation of images in the low-dose group had a 5-point lower proportion than that in the conventional dose group,and a 3-point higher proportion than that in the conventional dose group,with a statisti-cally significant difference(P＜0.05).The proportion of subjective evaluation scores for low-dose group images was similar to that of conventional dose,and the difference was not statistically significant(P＞0.05).The Signal-to-noise ratio(SNR)and contrast to noise ratio(CNR)values of the low-dose group were higher than those of the conventional dose group,and the difference was statistically significant(P＜0.05).Although the low-dose group significantly re-duces tube current and increases image SNR and CNR,the subjective image quality score of patients in the low-dose group is above 3 points,and the image quality can meet the requirements of disease diagnosis.The CTdoseindex(CTDI-vo),dose-length product(DLP),and effective dose(ED)values of patients in the low-dose group were lower than those in the conventional dose group,and the differences were statistically significant(P＜0.05).Conclusion:The personal-ized low-dose CT scan plan for adult chest based on patient BMI regulation tube current can meet clinical diagnostic re-quirements in terms of image quality,effectively reduce radiation dose and potential radiation risk.