99m Tc诊断过程中辐射场特征及其源强测量

摘要

为了掌握99mTc诊断全过程中所产生辐射场特征和源强,利用HPGeγ谱仪及其无源效率刻度技术,分析了99Mo和99mTc发射的主要γ射线对辐射场的贡献.使用主动测量和被动测量相结合的方式,测量了99mTc诊断过程中各个操作环节中的辐射源强.实验结果表明:99Mo-99mTc发生器淋洗前、后主要的γ射线发射率之比变化较大;随着距离的增加,99Mo-99mTc发生器、注射器和病人表面的γ辐射空气吸收剂量率快速衰减;99mTc诊断一天,放射性药品操作人员手部剂量达到0.41 mSv.%In order to have a good knowledge of the radiation feature and source strength in the whole process of diagnosis with 99mTc,we have analyzed the variation which is caused by the primary γ ray of 99Mo and 99mTc using HPGe γspectrometer and the technology of efficient calibration without source.And we also have measured the radiation intensity of source combing active measurement with passive measurement.The experimental results show that the ratio of the main y ray emissivity changes greatly before and after the elution.The absorbed dose rate of 99 Mo-99mTc generator,syringe,and the surface of patient decrease rapidly with the increase of distance.The hands of operates can totally suffer 0.41mSv dose in the whole process of diagnosis with 99mTc in one day.