新生儿床旁胸部DR摄影照射野外出现肢体影像原因分析

A cause analysis of showing limb imaging outside radiation field of bedside chest DR of newborn

目的:探讨新生儿床旁胸部数字X射线摄影(DR)时在照射野的周围出现淡淡肢体影像的原因。方法:从曝光剂量、透射线及漏射线3方面入手进行曝光实验,参考DR成像原理,逐一排查寻找出现淡淡肢体影像的原因。结果:通过实验数据分析,排除了曝光剂量过高、遮线器遮线板铅当量不足等因素,最终确定照射野外有散射线的存在,是形成照射野外肢体影像的辐射源。结论:焦点外射线和探测器的高灵敏度综合因素是造成照射野周围出现淡淡肢体影像的重要原因。

Objective:To investigate the causes of showing slight limb shadow at the periphery of radiation field post bedside chest digital radiography(DR)of newborns.Methods:The exposure experiments were carried out from the following three aspects:exposure dose,transmission ray and leaked ray,and the DR image-forming principle was referred to check and look for the cause of showing slight limb imaging one by one.Results:Through analyzing the experimental data,series of causes included exceed high exposure dose,insufficient lead equivalent of shutter diaphragm(shading ray device and shading ray plate)and so on were eliminated.Finally,existed scattered rays outside radiation field were confirmed to be radiation resource that formed limbs imaging outside radiation field.Conclusion:The comprehensive factors of higher sensitivity of ray detector and outside focal point is the important cause that produce slight limb imaging at the periphery of radiation field.