作者：陈平, 郭蓉, 潘晋孝, 冯艳如, 于乐

作者单位：中北大学信息探测与处理山西省重点实验室, 山西 太原 030051

关键词：X射线光学;能谱滤波分离;Geant4模拟;多谱CT成像

摘要：

为更加真实地刻画现代工业中各种复杂物质的结构特性,运用蒙特卡罗虚拟仿真技术,基于光子计数探测器的能谱分离成像思想,提出一种基于Geant4的能谱滤波分离虚拟平台构建方案,即运用Geant4模拟X射线CT成像系统,并通过在射线发射端添加滤波片实现能谱分离,获得具有窄谱特性的不同能段的能谱,从而得到近似单能的递变能量投影序列,完成虚拟平台的搭建。此外,为进一步说明该虚拟平台的可行性,该文还仿真模拟传统多能CT的投影过程,并将二者的结果进行比较分析。研究结果表明:该虚拟平台能较为准确地构建能谱滤波分离的多谱CT过程,从而更为快速、准确地实现成分复杂的物质识别及区分。

Study on virtual platform based on Geant4 energy spectrum filtering separation

CHEN Ping, GUO Rong, PAN Jinxiao, FENG Yanru, YU Le

Key Laboratory of Information Detection and Processing in Shanxi, The North University of China, Taiyuan 030051, China

Abstract: To characterize the structural characteristics of modern industrial complex substances more realistically, the paper applies Monte Carlo virtual simulation technology to present a construction scheme of a virtual platform based on Geant4 energy spectrum filtering separation according to the energy spectrum filtering separation and imaging ideology of photonic digital detector. Namely, Geant4 is used to simulate CT imaging system of a X ray and a filtering piece is added at the transmitting terminal of the ray to realize energy spectrum filtering separation, so that a spectrum of different energy bands with narrow spectral characteristics and a graded energy projection sequence approximate to single energy can be obtained and the construction of the virtual platform will be completed. In addition, to further illustrate the feasibility of the virtual platform, the paper also simulates the projection process of traditional multi-energy CT and conducts comparative analysis on their results. The results show that the virtual platform can accurately construct the multi-spectral CT process based on spectrum filtering separation and recognize and distinguish the substances with complex components quickly and accurately.

Keywords: X-ray optics;spectrum filter separation;Geant4 simulation;multi-spectral CT image

2016, 42(6): 65-69  收稿日期: 2015-12-10;收到修改稿日期: 2016-02-21

基金项目: 国家自然科学基金(61171179,61227003);山西省自然科学基金(2012021011-2)

作者简介: 陈平(1983-),男,安徽池州市人,副教授,主要从事CT理论与应用研究。

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