宁夏儿童头颅、胸部CT辐射剂量状况分析

Analysis of radiation doses from head and chest CT scanning for children in Ningxia

目的评估宁夏地区儿童头颅、胸部CT检查的辐射剂量水平,为不同年龄段儿童的CT辐射剂量优化提供基础。方法采用分层整群抽样的方法,实地采集宁夏地区不同市、县、区不同规模医院1-2周内儿童(≤15岁)头颅、胸部CT的扫描参数、容积CT剂量指数(CTDIvol)及剂量长度乘积(DLP),计算患者有效剂量(E)值;并将CTDIvol、DLP的第75百分位数(P75)与其他国家推荐的DRL值进行比较;所有儿童分4个年龄组:<1岁、1-5岁、6-10岁、11-15岁。结果走访调查39家医院,调查CT设备47台,采集头颅断层扫描1134例,胸部平扫636例。头颅CTDIvol、DLP的P75分别为:<1岁:44.2 mGy、456.2 mGy·cm;1-5岁:57.2 mGy、659.6 mGy·cm;6-10岁:61.1 mGy、668.7 mGy·cm;11-15岁:63.6 mGy、849.3 mGy·cm。胸部CTDIvol、DLP的P75分别为:<1岁:5.0 mGy、89.2 mGy·cm;1-5岁:5.9 mGy、124.8 mGy·cm;6-10岁:6.0 mGy、167.9 mGy·cm;11-15岁:7.1 mGy、235.0 mGy·cm。结论宁夏地区儿童胸部CT的辐射剂量与其他报道相近,但头颅CT的辐射剂量相对偏高,且各年龄段均存在偏高现象,尤以婴儿患者较著;应加强宁夏地区儿童头颅CT的辐射剂量优化与监管,增强儿科医生、放射科医生的剂量控制意识,提高对辐射相关风险的认识。

Objective To evaluate the radiation doses from head and chest CT examinations of children in Ningxia,and provide basic data for the optimization of CT radiation doses to children of different ages.Methods By using stratified cluster sampling method,the dose parameters on head and chest CT scanning,CTDIvol and DLP for the children under 15 years old were sampled within 1-2 weeks from hospitals at different levels in different regions of Ningxia for the calculation of effective doses.The 75th percentile(P75)of CTDIvol and DLP was compared with those recommended by other countries.All children included four age groups:up to 1 year old,1 to 5 years,6 to 10 years,11 to 15 years.Results There were 39 hospitals and 47 CT scanners in this survey,and 1134 head scanning and 636 chest scanning were investigating.The 75th percentile(P75)of CTDIvol and DLP for head scanning were 44.2 mGy and 456.2 mGy·cm for those up to 1 year old;57.2 mGy and 659.6 mGy·cm for 1 to 5 years old,61.1 mGy and 668.7 mGy·cm for 6-10 years old,and 63.6 mGy and 849.3 mGy·cm for 11-15 years old,respectively.The 75th percentile(P75)of CTDIvol and DLP for chest scanning were 5.0 mGy and 89.2 mGy·cm for those up to 1 year old,5.9 mGy and 124.8 mGy·cm for 1 to 5 years old,6.0 mGy and 167.9 mGy·cm for 6 to 10 years,and 7.1 mGy and 235.0 mGy·cm for 11 to 15 years old,respectively.Conclusions The chest CT radiation dose to children in Ningxia is close to the reported values,but the head CT radiation dose is relatively high in all age groups,especially in infants.The optimization and regulation of head CT radiation doses to children in Ningxia should be strengthened.It is high time to increase dose awareness for pediatricians and radiologists and raise awareness of radiation-related risks.