儿童CT扫描辐射剂量现状调查和诊断参考水平的初步探讨

Investigation of radiation dose and diagnostic reference levels in CT scanning for children

目的通过对全国范围内儿童CT辐射剂量的调查,了解儿童CT辐射剂量的现状,探讨儿童CT辐射剂量的诊断参考水平(DRL)。方法以2021年11月30日为起点,按时间倒叙回顾性收集全国儿科CT检查的辐射剂量报告。将所有CT扫描分为0~1个月、>1个月~4岁、>4~10岁、>10~14岁、>14~18岁5个年龄段;头颅平扫、鼻窦平扫、颞部平扫、颈部平扫、胸部平扫、腹部平扫、头颅增强、胸部增强、腹部增强9个检查项目。记录每次CT扫描的容积CT剂量指数(CTDI_(vol))和剂量长度乘积(DLP),其75%位数为DRL。将本次调查中头部平扫、胸部平扫、腹部平扫的DRL与我国专家共识和欧洲DRL指南进行比较。结果共收集到2019年3月至2021年11月间全国23个省、自治区、直辖市的33家医院,包括20家儿童专科医院、11家妇女儿童医院、2家综合医院的儿童CT检查19135次,获得了5个年龄段、9个检查项目的45个亚组的CT辐射剂量DRL。本调查DRL结果显示,5个年龄组头颅平扫的CTDI_(vol)为26.9~42.8 mGy,DLP为347~694 mGy·cm;胸部平扫的CTDI_(vol)为3.5~8.0 mGy,DLP为54~293 mGy·cm;腹部平扫的CTDI_(vol)为6.3~13.2 mGy,DLP为155~564 mGy·cm。我国专家共识的DRL基本相当于此次调查>4~10岁年龄组的DRL。与欧洲指南相比,头颅平扫辐射剂量差异不大,胸部平扫及腹部平扫低年龄组本次调查结果辐射剂量增高明显。结论本次调查显示了我国儿童CT常用检查项目的辐射剂量分布情况。部分项目辐射剂量水平与我国既往及国际相关组织发布的DRL不符,需要根据我国的实际建立自己的DRL,以指导儿童低剂量CT工作。

Objective To understand the current situation of CT radiation dose in children all over our country,and to explore the diagnostic reference level(DRL)of CT in children.Methods The radiation dose reports of pediatric CT examination were collected end to November 30,2021 and divided into five age groups:0-1 month,>1 month-4 years,>4-10 years,>10-14 years and>14-18 years.There were 9 scanning item such as head,nasal sinus,temporal bone,neck,chest,abdomen,head enhanced CT,chest enhanced CT and abdomen enhanced CT.In each item,volume CT dose index(CTDI_(vol))and dose length product(DLP)were selected as radiation dose parameters,the 75%percentile were selected for DRL.The DRL results of head,chest and abdomen were compared with the DRL published by Chinese Society of Radiology and European Commission.Results From March 2019 to November 2021,a total of 33 hospitals in 23 provinces were collected,including 20 children′s specialized hospitals,11 women′s and children′s hospitals and 2 general hospitals,including 19135 children′s CT scans.The DRL of 45 subgroups according to 5 age groups and 9 scanning items were obtained.The DRL results showed that the CTDI_(vol)in five age groups was 26.9-42.8 mGy,and the DLP was 347-694 mGy·cm for head;3.5-8.0 mGy,54-293 mGy·cm for chest;and 6.3-13.2 mGy,155-564 mGy·cm for abdomen.The DRL of the age group>4-10 years group in this investigation was agreed to the DRL of Chinese Society of Radiology.Compared with the European guidelines,there was little difference in the radiation dose of head scan,while the radiation dose of chest and abdomen in the young age group increased significantly.Conclusion This survey reveals the radiation dose level distribution of children CT in our country.The radiation dose level of some items was inconsistent with the DRL of relevant international organizations.So our own DRL is needed to be set up according to the actual clinical reality of our country as a guideline.