电子顺磁共振在体测量指甲剂量方法的可行性研究

摘要

目的 针对核应急医学救援剂量评估的需求,为解决指甲电子顺磁共振(EPR)剂量评估方法中机械诱发信号难以分离的问题,探讨指甲EPR在体测量的可行性.方法 利用自研的指甲在体EPR测量装置,对未剪碎指甲进行整体测量,在无机械诱发信号干扰的条件下研究指甲的本底信号及辐射诱发信号特性,探索通过水处理恢复本底信号的方法;开展指甲实际在体EPR测量实验,评价在体测量条件对EPR波谱的影响.结果 未剪碎指甲的本底信号分布服从正态分布,不同性别志愿者的指甲本底信号差异无统计学意义(P＞0.05);在2～10 Gy范围内建立了剂量响应关系,指甲辐射诱发信号半衰期约为5d;建立了变温结合水处理的本底信号恢复方法,处理后指甲EPR信号与本底信号差异无统计学意义(P＞0.05);获得了实际在体测量条件下的指甲EPR波谱.结论 利用本方法可以获得不含有机械诱发信号的EPR波谱,初步验证了指甲在体EPR测量用于剂量评估的可行性.%Objective To explore the feasibility of EPR in vivo fingernail dosimetry to address the difficulty in separating mechanically induced signals from fingernail EPR dosimetry for need of nuclear medical emergency aid.Methods Using the specially designed EPR in vivo measurement system,uncut fingernails were measured to obtain the characteristics of EPR signal without mechanically induced signals.The in vivo fingernail experiment was carried out to evaluate the impact of in vivo condition on the spectra.Actual in vivo measurement experiment was conducted to evaluate the interference of the in vivo condition on EPR spectra.Results The background signal distribution of uncut fingernails was obtained and background signals had no significant difference between male and female(P＞0.05).The dose response curve in the range of 2-10 Gy was established,and the half-life of the fingernail radiation-induced signal was approximately 5 d.The water treatment combined with temperature-changing was established for restoring the background signal.EPR signal obtained after restoring treatment has no significant difference with background signal (P＞ 0.05).The EPR spectra of in vivo fingernails were obtained.Conclusions The EPR spectra without mechanically induced signals can be acquired by this method.The feasibility of the in vivo fingernail EPR dosimetry is preliminarily verified.