儿童CT检查中不同体型特异性辐射剂量估计的初步对比分析  

Preliminary comparative analysis of the different size-specific dose estimates in CT examination for children

作　　者：郑丽丽[1] 廖甜 彭伟[1] 陈迢 张照喜[1] 陈浩[1] 贺瑶瑶 袁子龙[1] ZHENG Li-li;LIAO Tian;PENG Wei(Department of Radiology,Hubei Cancer Hospital,Wuhan 430079,China)

机构地区：[1]湖北省肿瘤医院放射科

出　　处：《放射学实践》2019年第8期916-919,共4页Radiologic Practice

基　　金：科技部国家重点专项计划项目(2016YFC0103400)

摘　　要：目的:比较基于有效直径(ED)和水等效直径(WED)的体型特异性剂量估计(SSDE)算法在评估儿童CT检查的辐射剂量中的差异。方法:回顾性分析在本院使用Siemens Somatom Definition AS+64排128层CT机进行CT检查的43例儿童患者的病例资料,其中行头部检查者13例、胸部15例、腹盆部15例。记录每例患儿CT检查中的CT容积指数(CTDIvol),计算有效直径(ED)和水等效直径(WED),并计算两者对应的辐射剂量(SSDEED、SSDEWED)。采用Bland-Altman分析来比较两组算法间的差异。结果:在儿童胸部腹盆部和头部CT检查中,基于ED计算的辐射剂量(SSDEED)较WED计算的辐射剂量(SSDEWED)分别低8.75%、低0.77%和高4.35%;各部位ED与WED的平均百分差异依次为10.49%、0.72%和-7.25%,95%一致性界限(LOA)分别为0.29%~20.70%、-21.87%~23.30%和-10.65%^-3.86%;各部位SSDEED与SSDEWED的平均百分差异依次为-8.75%、4.35%和-0.77%,LOA分别为和-15.69%^-1.8%、2.44%~6.26%和-17.3%~15.75%。结论:与基于有效直径的SSDE估计相比,基于水等效直径的SSDE能够更好地反映儿童体型和组织衰减特性,因而可以更加准确地估算儿童患者的CT辐射剂量。Objective:To investigate the difference between size-specific dose estimates(SSDE)based on effective diameter(ED)and water equivalent diameter(WED)in evaluating the radiation dose of CT scans in children.Methods:A total of 43 children who underwent CT scan at Siemens Somatom Definition AS+64-row 128-slice CT scanner were retrospectively enrolled in this study.Of the 43 cases,the examination position were the CT data of head in 13 cases,chest in 15 cases and abdomen-pelvis in 15 children were analyzed.The volume CT dose index(CTDIvol)in each CT scan was firstly recorded.Then,the ED,WED,and corresponding SSD EED and SSDE WED were calculated.And WED and SSD EWED were taken as references to compare the difference with ED and SSD EED.Results:In the chest,abdomen-pelvis and head examinations of children,due to the difference between ED and WED,SSD EED was lower than SSD EWED with a ratio of 8.75%,0.77%and-4.35%,respectively;the average percentage of difference and 95%limit of agreement(LOA)between ED and WED were 10.49%,0.72%,-7.25%,and 0.29%~20.7%,-10.65%^-3.86%,-21.87%~23.30%;the average percentage difference and 95%LOA between SSD EED and SSD EWED were-8.75%,4.35%,-0.77%,and 15.69%^-1.8%,2.44%~6.26%,-17.3%~15.75%,respectively.Conclusion:Compared with SSD EED,SSD EWED can better reflect the size and tissue attenuation characteristics of children,so it can more accurately estimate the CT radiation dose of children patients.

关 键 词：儿童 有效直径 水等效直径 体型特异性剂量估计 辐射剂量 

分 类 号：R814.42[医药卫生—影像医学与核医学] R814.2[医药卫生—放射医学]