MV级EPID成像系统中滤过板的应用  

Application of Filtration Plate in Megavoltage EPID

作　　者：石强[1] 罗文芸[1] 周诗情[1] 张靖[1] 王传珊[1] 吴国华[2] 查元梓[2] 蒋马伟[2] 

机构地区：[1]上海大学射线应用研究所,上海200444 [2]上海交通大学医学院附属新华医院放疗科,上海200092

出　　处：《原子能科学技术》2012年第7期885-889,共5页Atomic Energy Science and Technology

基　　金：上海市科委重点项目资助(08JC1410200)

摘　　要：与kV级X射线成像相比,MV级电子射野影像系统(EPID)成像质量较差,图像模糊,影响患者图像定位和摆位验证的精确性。本文结合Monte Carlo模拟计算的方法,在不改变治疗靶的现有MV级EPID系统中,提出增加滤过板进行康普顿散射线的滤过,通过Monte Carlo模拟、Matlab作图、临床实验,得出在6MV级EPID系统中,增加1层2mm厚铜材料的滤过板,有助于成像质量的改善。EPID with megavoltage X-rays suffers from poor quality compared to kilovolt X-rays,so the accuracy of the patient positioning and position verification is affected.By using Monte Carlo method,a new way was explored to raise the resolution in current EPID system without altering its target.According to Monte Carlo simulation,it was found that the primary cause leading to a low resolution was the Compton scattering rays with low energy.The key technique raising the resolution and definition is to avoid the interference of low energy X-ray.From the simulation results and the experimental results by clinical megavoltage EPID,it can be found that the 2 mm Cu filtration plate is more helpful in improving the image quality.

关 键 词：EPID 滤过板 MONTE CARLO模拟 

分 类 号：TL503.4[核科学技术—核技术及应用] R331[医药卫生—人体生理学]