头颈部、胸部CT扫描频次分布及其剂量水平研究

Research on frequency distribution and dose levels of head,neck,chest CT scans

目的通过调查研究,掌握上海市头颈部、胸部CT扫描频次分布及其剂量水平。方法采用分层典型抽样的方法,以上海市的25家医院为调查对象,通过上海市放射卫生综合监测管理信息系统、各医院的医学影像信息系统(PACS)和医学信息系统(HIS),收集受检者基本信息、检查部位、扫描参数、受检者剂量报告等信息,输入计算机进行处理和分析。结果所调查的1732286人次的CT检查中,头颈部、胸部检查在儿童受检者占75%以上,在成年人受检者则占60%以上。对于成年人受检者,颅脑CT、眼部CT和胸部CT的CTDIw的平均值分别为55.4 mGy、43.1 mGy和12.4 mGy,CTDIvol的平均值分别为56.1 mGy、47.0 mGy和10.6 mGy。颅脑CT、耳道CT和胸部CT的剂量长度乘积(DLP)的平均值分别为603.4 mGy·cm、241.8 mGy·cm和293.6 mGy·cm。结论CT检查中,头颈部、胸部所占比例很高,不同类型CT检查导致的剂量水平存在明显区别。

Objective To master the frequency distribution and dose levels of head,neck,chest CT scans in Shanghai.Methods Stratified typical sampling method was used and 25 hospitals were chosen for investigation.The patient’s basic information,examination types,scan parameters and patient’s dose reports were gathered from the Shanghai Comprehensive Information System of Radiation Protection,the hospital’s medical imaging information system(PACS)and medical information system(HIS),.Data was input the computer for processing and analyzing.Results Among the 1732286 CT examinations,head,neck and chest examinations accounted for more than 75 percent in children,more than 60 percent in adults.For adult,the mean values of weighted CT dosimetry index(CTDIw)of head,eye and chest CT scans were 55.4 mGy,43.1 mGy and 12.4 mGy,respectively.The mean values of volume CT dosimetry index(CTDIvol)of head,eye and chest CT scans were56.1 mGy,47.0 mGy and 10.6 mGy,respectively.The average dose-length product(DLP)of head,ear canal and chest CT scans were 603.4 mGy·cm,241.8 mGy·cm and 293.6 mGy·cm,respectively.Conclusion Head,neck and chest CT scans make up a great proportion of CT examinations,and obvious difference was found among various types of CT examinations.