基于编码板和针孔的大视野放射源定位系统  

Large field-of-view radioactive source location system based on a coded aperture and pinholes

作　　者：刘玉洁 戴甜甜[3] 江年铭 侯岩松 魏清阳[1,2,4] LIU Yujie;DAI Tiantian;JIANG Nianming;HOU Yansong;WEI Qingyang(School of Automation and Electrical Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Engineering Research Center of Industrial Spectrum Imaging,University of Science and Technology Beijing,Beijing 100083,China;Department of Radiation Oncology,China-Japan Friendship Hospital,Beijing 100029,China;Beijing Novel Medical Equipment Ltd.,Beijing 102206,China)

机构地区：[1]北京科技大学自动化学院,北京100083 [2]北京科技大学北京市工业波谱成像工程技术研究中心,北京100083 [3]中日友好医院放射肿瘤科,北京100029 [4]北京永新医疗设备有限公司,北京102206

出　　处：《清华大学学报（自然科学版）》2024年第8期1516-1520,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划项目(2022YFC2402000);国家自然科学基金面上项目(11975044,12375337)。

摘　　要：近年来,基于编码孔径成像技术的γ相机被广泛用于放射源的定位和监测,但其成像视野范围有限。虽然可采用多个编码板探测器同时探测的方式扩大视野范围,但会增加成本且设备较为笨重。因此,该文提出了一种编码板和针孔混合系统,编码板全编码视场角和半伪影视场角分别为19.33°和70.80°,增加的针孔可将系统视野扩展到123.40°。进一步基于vGATE仿真平台进行了Monte Carlo仿真实验,结果显示所设计系统在编码板视野内实现了2.95°的空间角度分辨率,在扩展的针孔视野内实现了6.30°的空间角度分辨率,可对3 m处10mCi的放射源有效成像。[Objective]Gamma-ray detection using a nuclear radiation locator is critical for monitoring,locating,and processing radioactive sources.In recent years,gamma cameras based on coded aperture imaging techniques have been extensively utilized to identify and monitor radioactive sources.However,these detectors have limitations in terms of the imaging field.To accurately determine the specific location of radioactive sources,constant adjustment of the detection angle is required,which is often time-consuming.To expand the detection field,multiple coded aperture cameras can be used simultaneously,but this approach increases cost and equipment complexity.Some researchers have attempted to combine Compton and coded aperture imaging techniques.While the Compton camera can extend the field-of-view(FOV)to 4π,this method is complicated,costly,and limited to detecting high-energy rays.As a result,the combination of these two techniques proves inadequate when searching for low-energy sources.In this work,we proposed a system and method for locating radioactive sources with a large FOV based on combining a coded aperture with pinholes.This method addresses the limited FOV issue encountered in the aforementioned system.[Methods]The coded aperture component of the system uses a modified uniformly redundant array as the uniform redundant array mask.The base mode class is 11,with a unit size of 3.3 mm×3.3 mm,leading to a total size of 69.3 mm×69.3 mm.The mask thickness is 9 mm,and tungsten is used as the material.The detector section includes a 26×26 NaI(Tl)array,where each crystal pixel has dimensions of 1.45 mm×1.45 mm×6.00 mm.A crystal gap of 0.2 mm exists between each pixel,and the distance between the center of the coded aperture and the position-sensitive sensor is 77.5 mm.For the pinhole part of the system,a tapered pinhole with a center size of 4 mm is used.The pinhole is embedded in a shield with equally large pinholes on all four sides.For performance assessment of the system,Monte Carlo simulation experiments were

关 键 词：编码孔径γ相机 针孔成像 大视野 

分 类 号：O572.212[理学—粒子物理与原子核物理]