基于Geant4/GATE平台模拟移动式锥形束CT成像  

Simulation of mobile cone-beam CT imaging based on the Geant4/GATE platform

作　　者：明鑫 王涌鉴 翟贺争 杨成文[4] 孟慧鹏[5] 杨舰 薄文柱 MING Xin;WANG Yongjian;ZHAI Hezheng;YANG Chengwen;MENG Huipeng;YANG Jian;BO Wenzhu(Tianjin Medical University,Tianjin 300203 China;Tianjin University,Tianjin 300072 China;Institute of Radiation Medicine,Chinese Academy of Medical Sciences,Tianjin 300192 China;Tianjin Medical University Cancer Hospital,Tianjin 300060 China;Characteristic Medical Center of PAP,Tianjin 300162 China;Tianjin Jinxi Medical Equipment Co.,Ltd.,Tianjin 300385 China)

机构地区：[1]天津医科大学,天津300203 [2]天津大学,天津300072 [3]中国医学科学院放射医学研究所,天津300192 [4]天津医科大学肿瘤医院,天津300060 [5]武警特色医学中心,天津300162 [6]天津金曦医疗设备有限公司,天津300385

出　　处：《中国辐射卫生》2021年第6期706-709,719,共5页Chinese Journal of Radiological Health

基　　金：国家自然科学基金(11805144)。

摘　　要：目的利用Geant4/GATE平台建立移动式锥形束CT扫描成像模型,探究图像优化方法,提高锥形束CT图像质量。方法基于蒙特卡罗模拟算法中的Geant4/GATE平台对移动式锥形束CT进行成像模拟,构建放射源、平板探测器及测试模体的模型,获得锥形束CT的投影数据;比较3种图像重建算法(FDK,SART和EM)对设计的数字化模体进行图像重建,并模拟出2档X射线的成像。结果3种重建算法中FDK算法最快;SART算法重建图像质量对比度较高、伪影较低,图像质量较优;EM算法噪声最小但不同密度插件图像边界模糊。SART算法重建70 kV X射线图像散射程度较大,而140 kV X射线重建图像质量较好。结论基于Geant4/GATE建立的移动式锥形束CT仿真平台,可以获取数字化模体的三维重建图像,为后续移动式锥形束CT图像质量优化、质量控制等方面的研究提供理论依据。Objective To simulate mobile cone-beam computed tomography(CBCT)imaging based on the Geant4/GATE platform and to explore the optimization method to improve image quality.Methods Mobile CBCT imaging was simulated based on the Geant4/GATE platform of Monte Carlo algorithm to establish the models of X-ray source,flat panel detector,and phantom,and projection data of CBCT were obtained.Three image reconstruction algorithms(FDK,SART,and EM)were used for image reconstruction of the designed digital phantom with the projection data at two X-ray energy levels.Results FDK was the fastest algorithm,SART had high contrast quality,low artifacts,and high image quality;EM had minimum noise but fuzzy boundaries of inserts of different density.With the SART algorithm,the images reconstructed at 70 kV X-ray were scatters,while the images reconstructed at 140 kV X-ray had high quality.Conclusion Simulation of mobile CBCT based on the Geant4/GATE platform can reconstruct 3D images of the digital phantom,which provides a theoretical basis for further research on image quality optimization and quality control of mobile CBCT.

关 键 词：CBCT 图像重建 散射校正 

分 类 号：R816[医药卫生—放射医学]