基于辐射剂量结构化报告的未成年人胸部CT检查体型特异性剂量分析

Size-specific dose estimates of chest CT in children based on radiation dose structured reports

目的通过辐射剂量结构化报告(RDSR)及关键影像的自动收集,比较不同年龄段未成年人在胸部CT检查中的体型特异性剂量估计(SSDE)的差别。方法应用Teamplay软件通过影像归档和通信系统(PACS)自动抓取了404例年龄在0~18岁的胸部CT检查的辐射剂量结构化报告,并通过CT断面影像计算出水等效直径(WED)及SSDE。应用方差分析比较SSDE等剂量参数在不同年龄段的差异,应用Pearson相关分析探讨SSDE与容积CT剂量指数(CTDIvol)的关系。结果所有研究对象的SSDE平均值为(4.70±3.29)mGy,且随着年龄增长而增加,在各年龄段之间差异有统计学意义(F=46.11,P<0.01)。SSDE与CTDIvol在1岁至18岁年龄段呈高度线性相关(|r|≥0.92,P<0.01)。结论在日常工作中应用SSDE进行扫描质量控制,部分年龄段的SSDE水平可以用CTDIvol线性转换而成,转换因子随年龄段不同而变化。随着年龄的增加,SSDE与CTDIvol差别逐渐减小,因此SSDE比较适合评估未成年人CT检查辐射剂量。

Objective To compare the size-specific dose estimates(SSDE)among children groups with different age ranges by radiation dose structured reports(RDSR)and automatic collection of key images.Methods Four hundred and four patients(age range 0 to 18 years)were enrolled through automatically capturing the radiation dose structured reports with Teamplay software on the PACS,and the water equivalent diameter(WED)and SSDE were calculated by measurement on the CT axial images.The differences of SSDE and other radiation parameters in different groups were analyzed by using ANOVA method,and the relationship between SSDE and CTDIvol was analyzed by Pearson correlation coefficient.Results The mean value of SSDE for all subjects was(4.70±3.29)mGy,and increased with the increase of age,showing significant differences among different age groups(F=46.11,P<0.01).There was a highly linear correlation between SSDE and CTDIvol from 1 year to 18 years old(|r|≥0.92,P<0.01).Conclusions This study provides a method to apply SSDE to scan quality control in daily work.The result shows that the SSDE level in some age groups can be converted linearly by CTDIvol,and the conversion factor varies with different age groups.The difference between SSDE and CTDIvol gradually decreases with age,so SSDE is more suitable for evaluating the radiation dose of CT examination for children.