基于体重指数的个性化肺部低剂量CT扫描在体检筛查中的应用

Application of personalized low-dose CT scanning of the lung based on body mass index in physical screening

目的 探讨不同体重指数(BMI)下肺部个性化低剂量CT扫描方案在体检筛查及降低辐射剂量中的作用。方法 随机将2018年4~6月健康体检者分成两组,A组CT检查管电压固定100kV,管电流视体检者BMI(单位:kg/m2)不同,给予相应的扫描方案(低BMI组:BMI<20,20mA;中BMI组:20≤BMI≤25,30mA;高BMI组:BMI>25,40mA);B组行常规低剂量肺部CT检查,管电压固定100kV,管电流固定40mA;对比两组体检者的有效辐射剂量、图像质量及结节检出率。结果 所有体检图像主观评分均>3分,满足诊断要求;A组图像主观评分为(4.6±0.7)分,B组图像主观评分为(4.5±0.5)分,两组差异无统计学意义(P>0.05);A组有效辐射剂量为(0.47±0.07)msv,B组有效辐射剂量为(0.52±0.09)msv,A组明显低于B组(P<0.05)。A组有34例发现阳性结节(34/157,21.2%),其中老年人20例,吸烟者22例;B组有37例存在阳性结节(37/162,22.8%),其中老年人23例,吸烟者27例;两组在结节检出率及结节检出分布情况无统计学意义(P>0.05)。结论 基于BMI的个性化肺部低剂量CT扫描在肺部结节筛查中能降低辐射剂量,且不影响图像质量。

Objective To explore the effect of individualized low-dose CT scanning based on different body mass index(BMI) in physical screening and radiation dose reduction. Methods Healthy controls involved in this study from April to June2018 were divided into two groups randomly.In group A,the voltage of CT tube was fixed at100 kV,and according to different BMI (unit:kg/m2) of the patients,corresponding scanning schemes of tube current were carried out(low BMI group:BMI<20,20 mA;middle BMI group:20≤BMI≤25,30 mA;high BMI group:BMI>25,40 mA).In group B,routine low-dose lung CT examination was performed,tube voltage was fixed at100 kV,and the tube current was fixed at 40 mA.And then,effective radiation dose,image quality and nodule detection rate were compared between the two groups. Results The subjective scores of all physical examination images were>3 points,which met the diagnostic requirements.The subjective scores of the group A and the group B were(4.6±0.7) and (4.5±0.5) respectively,difference was not statistically significant( P > 0.05 ).The effective radiation dose of the group A was(0.47±0.07)msv,and that of the group B was(0.52±0.09) msv,and the effective radiation dose of the group A was significantly lower than that of the group B( P <0.05).Positive nodules were found in 34 cases(34/157,21.2%) in the group A,including20 elderly people and22 smokers,and positive nodules were found in 37 cases(37/162,22.8%) in the group B,including23 elderly people and27 smokers.There was no statistically significant difference in the detection rate and distribution of nodules between the two groups( P >0.05). Conclusion Individualized low-dose CT scanning based on BMI can reduce radiation dose in the screening of lung nodules without affecting the image quality.