儿童CT检查不同辐射剂量指标差异性及相关性分析  

Analysis of the differences and correlations of different radiation dose indicators in CT examination for children

作　　者：张见 边传振 张晓军 ZHANG Jian;BIAN Chuan-zhen;ZHANG Xiao-jun(Department of Radiology,Children's Hospital of Nanjing Medical University,Nanjing 210000,China;不详)

机构地区：[1]南京医科大学附属儿童医院放射科,江苏南京210000

出　　处：《中国医学装备》2023年第7期10-14,共5页China Medical Equipment

基　　金：江苏省政府留学基金(JS-2018-137)“儿童神经母细胞瘤的多模态分期及预后”;江苏省妇幼保健课题(FYX201816)“3DMRCP及DTI在新生儿胆汁淤积性黄疸早期诊断中的应用价值”;南京市医学科技发展基金(QRX17169)“儿童1型糖尿病功能成像”。

摘　　要：目的:比较儿童CT检查中容积CT剂量指数(CTDI_(vol))与基于水当量直径(dw)的体型特异性剂量估算(SSDE_(dw))两种辐射剂量估算方法在评估儿童CT辐射中的差异,探讨两种剂量估算方法的相关性及快速计算SSDE_(dw)的方法。方法:收集在医院行CT检查的1210例头颅、1122例胸部及844例腹盆部患儿影像学资料,根据年龄将所有患儿分为0~≤1岁组、1~≤5岁组、5~≤10岁组和10~≤15岁组,测量最中间轴位图像的兴趣区面积(Aroi)及面积内平均CT值(CTroi)计算SSDE_(dw),检验4组不同年龄段患儿CTDI_(vol)与SSDE_(dw)间的差异及相关性,并根据其相关性基于CTDI_(vol)快速计算SSDE_(dw)。结果:4组不同年龄段患儿头颅、胸部及腹盆部CTDI_(vol)与SSDE_(dw)间差异均有统计学意义(t=53.96,t=-220.99,t=-116.62;P<0.001);头颅除0~≤1岁组CTDI_(vol)低估其辐射剂量外,其余3组CTDI_(vol)均高估辐射剂量;胸部、腹盆部各组CTDI_(vol)均低估其辐射剂量。头颅、胸部及腹盆部CTDI_(vol)与SSDE_(dw)均有强正向相关性(r_(头颅)=0.98,r_(胸部)=0.97,r_(腹盆部)=0.98;P<0.05);其回归方程分别为:头颅[SSDE_(dw)=2.45 x^(0.54)(x为CTDI_(vol),R2=0.95)];胸部[SSDE_(dw)=2.05+3.36 log(x)(x为CTDI_(vol),R^(2)=0.96)];腹盆部[SSDE_(dw)=2.65 x^(0.72)(x为CTDI_(vol),R^(2)=0.96)]。结论:相较于CTDI_(vol),SSDE_(dw)更能准确反映儿童头颅、胸部及腹盆部辐射剂量。通过CTDI_(vol)与SSDE_(dw)间回归模型,可以简单快速的预估其SSDE_(dw),对于辐射剂量精确控制具有重要意义。Objective:To compare the differences between volumetric computed tomography dose index(CTDI_(vol))and size-specific dose estimation(SSDE_(dw))on the basis of water equivalent diameter in evaluating the CT radiation on children,and to explore the correlations between the two kinds of dose estimation methods and the methods of quickly calculating SSDE_(dw).Methods:The imaging data of 1217 patients,1122 patients and 884 patients who respectively underwent CT examination on head,chest and abdomen-pelvis were analyzed,and they were divided into 0-≤1year old group,1-≤5years old group,5-≤10years old group and 10-≤15years old group according to their ages.The area region of interest(Aroi)and average CT value of region of interest(CTroi)within the area of the image at the middle axis were measured for calculating the SSDE_(dw).The differences and correlations between CTDI_(vol) and SSDE_(dw) in 4 different age groups were tested.According to the correlation,the SSDE_(dw) was quickly calculated based on the CTDI_(vol).Results:There were significant differences between CTDI_(vol) and SSDE_(dw) in head,chest and abdomen-pelvis in 4 different age groups(t=53.96,t=-220.99,t=-116.62,P<0.001).For head,the CTDI_(vol) of other groups overestimated the radiation dose except that of 0-≤1year old group underestimated the radiation dose,and the CTDI_(vol) of each group in chest and abdomen-pelvis underestimated the radiation dose.There were strongly positive correlations between CTDI_(vol) and SSDE_(dw) in head,chest and abdomen-pelvis(r_(head)=0.98,r_(chest)=0.97,rabdomen-pelvis=0.98,P<0.05),and the regression equations of them respectively were:head[SSDE_(dw)=2.45x^(0.54)(x=CTDI_(vol),R^(2)=0.95)],chest[SSDE_(dw)=2.05+3.36log(x)(x=CTDI_(vol),R^(2)=0.96)],abdomen-pelvis[SSDE_(dw)=2.65x^(0.72)(x=CTDI_(vol),R^(2)=0.96).Conclusion:Compared with CTDI_(vol),SSDE_(dw) can more accurately reflect the radiation dose of children's head,chest and abdomen-pelvis.The SSDE_(dw) can be simply and quickly estimated through regression mode

关 键 词：儿童 X射线计算机断层扫描(CT) CT剂量指数(CTDI_(vol)) 体型特异性剂量估算 回归模型 

分 类 号：R814.2[医药卫生—影像医学与核医学]