目的 探讨不同铅当量和镜片大小铅眼镜对介入放射工作人员眼晶状体的防护效果.方法 利用MCNPX软件和人体体素体模,模拟计算在不同投照体位条件下介入放射学工作人员佩戴不同铅眼镜时的眼晶状体剂量;通过在仿真人体模上布放眼晶状体剂量计开展实验测量,以验证理论计算结果.结果 模拟计算结果表明,当单个镜片大小为20 cm2时,佩戴0.1~1.0mmPb(铅)眼镜可降低眼晶状体受照剂量系数为3~9;剂量降低系数(DRF)不仅与眼镜的铅当量有关,而且还取决于X射线的投照体位;当镜片的铅当量超过0.35 mm Pb时,随着镜片铅当量的增加,剂量的进一步降低并不明显.在相同铅当量条件下,当镜片尺寸为6~30 cm2时,DRF与镜片的大小成线性增长关系.模拟计算数值和实验结果基本吻合.结论 为有效地保护介入放射学工作人员的眼晶状体,推荐佩戴铅当量为0.5 mm Pb且镜片尽量大的防护眼镜.
Objective To study the shielding effect of equivalent thickness and size of lead glasses on eye lens of interventional radiologists.Methods Based on the human voxel phantom and MCNPX software,doses to eye lens of radiologists were simulated under different conditions of wearing lead glasses and beam projections,and measurements were performed with anthropomorphic phantom placed with eye lens dosimeters to verify simulation results.Results The results showed that the dose to eye lens reduced by a factor from 3 to 9 when the equivalent thickness of glasses ranged from 0.1 to 1.0 mm Pb with a len size of 20 cm2.The dose reduction factors (DRF) not only depended on the lead equivalent,but also on the beam projection of X-rays.However,the increase in DRF was not significant whenever the lead equivalent of glasses was larger than 0.35 mm.Furthermore,the DRF was proportional to the size of glass lens from 6 to 30 cm2 with the same lead equivalent.The simulation results were in well agreement with the measured ones.Conclusions For more reasonable and effective protection of the eye lens of interventional radiologists,a pair of glasses with a lead equivalent of 0.5 mm and large-sized lens is recommended.