层面组织结构含量与SSDE在腹盆部CT扫描中的相关性研究  

Study on correlation between tissue structure contents and size specific dose estimate in abdomen-pelvis CT scan

作　　者：郑小丽 徐健[2] 王振[2] 舒震宇[2] 毛德旺[2] ZHENG Xiaoli;XU Jian;WANG Zhen;SHU Zhenyu;MAO Dewang(Graduate school of Zhejiang Chinese Medical University,Hangzhou 310053,P.R.China;Department of Radiology,Zhejiang Provincial People’s Hospital,People’s Hospital of Hangzhou Medical College,Hangzhou 310014,P.R.China)

机构地区：[1]浙江中医药大学研究生院,浙江杭州310053 [2]浙江省人民医院杭州医学院附属人民医院放射科,浙江杭州310014

出　　处：《医学影像学杂志》2020年第2期284-287,共4页Journal of Medical Imaging

基　　金：浙江省卫生计生委医药卫生科技计划面上项目(编号:2017KY205;2018KY227)。

摘　　要：目的探讨腹盆部CT扫描中层面内组织结构含量与体型特异性剂量估算值(size specific dose estimate,SSDE)的相关性。方法连续收集我院106例腹盆部平扫的患者,记录每例患者的容积CT剂量指数(volume CT dose index,CTDI vol)及体质量指数(body mass index,BMI)。测量每例患者中心层面面积(A ROI)及平均CT值(CT ROI),计算每例患者的水等效直径(water equivalent diameter,d w)、体型转换系数(size dependent specific conversion factor,f)及体型特异性剂量估算值(size specific dose estimate,SSDE)。利用QCT测量分析软件测量中心层面组织结构的含量,比较层面内各组织结构与SSDE相关性及相关程度。结果层面内脂肪与SSDE强相关(r=0.632,P<0.05),而肌肉和骨组织与SSDE的相关性无统计学意义(r=0.038,P>0.05;r=0.023,P>0.05)。层面内脂肪含量和BMI与f存在很好的线性负相关(R 2=0.812,P<0.05;R 2=0.663,P<0.05)。结论层面内脂肪含量与SSDE相关性很好,可潜在估算成人腹盆部CT扫描时所受的辐射剂量。Objective To compare the correlation between individual tissue structure content at the central slice of the scan and size specific dose estimate(SSDE)in abdominal and pelvic CT scans.Methods A total of 106 consecutive adult patients were performed CT scan for abdomen-pelvis using 128 slices CT.All of CTDI vol values in the dose report and BMI were documented.The mean CT number(CT ROI)and area of ROI(A ROI)at the central slice of the scan range were measured.The water-equivalent diameter(d w),individual size dependent conversion factor(f)and size specific dose estimate(SSDE)were calculated.QCT analysis software was used to quantify individual tissue structure content at the central slice.The bi-variables correlation analysis was executed for the correlation between the individual tissue structures and SSDE at the central slice of the scan range.Results A strongly positive correlation was shown in fat content and SSDE(r=0.632,P<0.05),however it was weakly associated with muscle and bone(r=0.038,P>0.05;r=0.023,P>0.05).There was a good negative linear correlation between fat content and BMI with f(R 2=0.812,P<0.05;R 2=0.663,P<0.05).Conclusion Fat content is strongly correlated with SSDE and may be potentially practical to estimate the radiation dose to adult patients underwent abdomen-pelvis CT scan.

关 键 词：容积CT剂量指数 水等效直径 体型特异性剂量估算值 体层摄影术 X线计算机 

分 类 号：R816.5[医药卫生—放射医学] R814.42[医药卫生—临床医学]