医用X射线CT主要检查类型所致成年受检者剂量研究  

Research on the Radiation Doses to Adults Receiving from Main Types of Medical X-ray CT Examinations

作　　者：高林峰[1] 郑钧正[1,2] 卓维海[2] 王彬[1] 曲良勇 姚杰[1] 钱爱君[1] 

机构地区：[1]上海市疾病预防控制中心,上海200336 [2]复旦大学放射医学研究所,上海200032 [3]上海中冶职工医院,上海200941

出　　处：《辐射防护》2013年第2期74-81,共8页Radiation Protection

基　　金：上海市放射卫生重点学科建设项目(08 GWZX 0602);卫生行业科研专项(201002009);上海市公共卫生人才培养计划项目(GWDTR 201206;GWDTR 201208);上海市卫生局科研项目(2007177)

摘　　要：研究与掌握广泛普及的医用X射线CT(X-CT)所致受检者的剂量水平,是加强医疗照射防护的一个关键课题。在上海市"十一五"期间医疗照射水平调查研究中,根据全市拥有X-CT机各种品牌及其在各级医院实际应用比例情况,抽取全市约占30%的X-CT机计45台进行现场调研。累计针对8种常见主要检查类型的500例成年受检者,调查他们进行X-CT检查时所用的扫描参数及其相关剂量学信息,借助剂量转换系数等估算其所致典型有效剂量。研究结果表明,头颅、胸部和腹部的X-CT扫描中,各自加权CT剂量指数(CTDIw)的均值分别为55.4 mGy、12.5 mGy和18.4 mGy,而相应的剂量长度乘积(DLP)的均值分别为603 mGy.cm、294 mGy.cm和415 mGy.cm。由此估算出头颅、胸部和腹部X-CT扫描所致成年受检者有效剂量的典型值分别为1.4 mSv、5.3 mSv和7.5 mSv。头颅扫描检查的CTDIw值通常高于耳道、眼部或鼻窦的诊断检查。显然,必须进一步加强X-CT扫描检查的影像质量及其所致剂量的优化匹配研究,尤其必须注意恰当选取各类X-CT检查所用的扫描参数,并不断完善相应的X-CT检查医疗照射指导(参考)水平,推动X-CT检查的医疗照射防护最优化。To study and master the doses to examinees receiving from the wide spread X examinations,is a key issue for strengthening the medical radiation protection. In the studies CT the medical exposure levels during the Eleventh Five - Year Plan period in Shanghai, based on the brands of X - CT scanners and their distributions in different levels of hospitals, a total of 45 sets （ about 30% of all） of scanners were selected for the field study. Among the 8 commonly performed examinations,the scan parameters and their relevant dosimetry information for 500 adults were collected, and their typical effective doses were estimated with the dose conversion factors. The results showed that the averages of weighted CT dose index （CTDI~）were 55.4,12.5 and 18.4 mGy,and the dose length products （DLP） were averaged to be 603,294 and 415 mGy＂ cm, for the skull, chest and abdomen X- CT scans, respectively. The typical effective doses were estimated to be 1.4,5.3, and 7.5 mSv for adults in the head, chest and abdomen X - CT scans,respectively. The values of CTDIw for skull scans were generally higher than those for the ear canal, eye, or sinus examinations. It is clear that the optimization between the image quality and the radiation dose should be further strengthened. Particular attentions should be paid in selecting the scanning parameters for various types of X - CT scans, and the diagnostic reference levels for X - CT examinations should be continuously improved.

关 键 词：X—CT CT剂量指数 剂量长度乘积 有效剂量 诊断参考水平 

分 类 号：R144.1[医药卫生—公共卫生与预防医学]