2018—2019年湖北省医疗照射频度及所致集体剂量研究

Frequency and collective dose of medical radiation exposure in Hubei Province in 2018-2019

目的了解湖北省医疗照射频度及X射线诊断所致集体剂量影响因素,为医疗照射防护决策提供依据。方法普查全省2018—2019年度3178家放射诊疗机构基本情况、放射诊疗类型、放射诊疗设备配置、医疗照射频次等信息,采用分层随机抽样原则抽取36家医院,调查26项X射线检查项目的应用频次,结合调查数据及既往文献,估算湖北省X射线诊断所致年集体剂量。结果全省配置放射诊疗设备共6843台,放射诊疗总频次为33771855人次,其中X射线诊断占98.41%。全省X射线诊断所致年集体剂量估算结果为65399.55人·Sv,人均年集体剂量为1.10mSv,其中CT检查所致年集体剂量占比86.90%。结论医疗照射应用频度呈持续增长态势,且城乡、地区和各级机构之间发展不平衡。在各项X射线检查中,CT检查应用的增长速度最快,所致年集体剂量份额最高。应避免非正当性CT检查,并合理控制单次CT扫描的辐射剂量才能有效减少放射检查所带来的长期健康风险。

Objective To assess the medical radiation exposure frequency and find out the main factors related to the collective dose derived from X-ray diagnosis procedures.Methods A survey of 3178 hospitals was conducted to collect the basic information such as types of medical radiation,allocation of radiological diagnosis and treatment devices,the frequency of radiologic examinations,etc.By using a stratified sampling method,36 hospital were selected and more specific details,including 26 types of diagnostic radiologic examinations,were collected to estimate the collective dose to the population in Hubei,combining with the previous literature.Results A total number of 6843 radiological diagnosis and treatment devices were covered and 33771855 medical radiologic procedures were counted in this survey.The result showed a annual frequency of 569.79 examinations per 1000 population for all types of procedures.A large variation was revealed among different areas and the highest area was with a 4-fold frequency of the lowest area.Although tertiary hospitals accounted for 4.40%of the total hospitals,48.42%procedures were carried out in them.The collective effective dose from X-ray diagnosis in Hubei was 65399.55man·Sv,and the average annual effective dose was 1.10mSv,while contribution from CT scans accounted for 86.90%of the dose.Conclusion The frequency of medical radiologic procedures presented a consistent increase in Hubei province,with a uneven development among hospitals from urban and rural areas,or from different regions,or from different levels.Among all types of X-ray examinations,CT scan frequency had the fastest growth rate and accounted for the major annual collective effective dose.In order to reduce the health risk from medical radiologic exposure,CT scan need to be applied more properly and the radiation dose per single CT scan need to be limited to a reasonable level.