摘要
模拟构建了双层康普顿相机,利用康普顿散射原理,获取γ光子在两层探测器发生散射前后沉积的能量和位置信息,通过一定算法进行图像重建,获得放射源位置信息。该相机具有灵敏度高、体积小、应用范围广等优点。通过蒙特卡罗方法模拟了具有双层条状结构位置灵敏探测器(散射探测器、吸收探测器)组成的康普顿相机,其两层探测器分别由Si和Ge材料构成。利用反投影图像重建算法实现了放射源图像重建,当单点源与探测器距离为40 mm时,成像的效率为0.38%,位置分辨率达到8.0 mm,角分辨率达到3°。对于不同位置和不同个数点源的情况下,检验了反投影重建算法在康普顿相机放射源空间重建中的效果。
Background： Due to its imaging principle advantages and the development of detectors, nuclear electronics, Compton camera has once again put forward. Purpose： This study aims to build a Compton cameravia Monte Carlo simulation and test its backprojection algorithm.Methods： By using Monte Carlo simulation software GEANT4, a Compton camera with stripes structure is designed and data for reconstruction image of source is read out. Backprojection imaging reconstruction algorithm is studied for getting the reconstruction of source.Results： Using backprojection algorithm and simulated Compton camera, when the distance between source and the scattering detector is 40 mm, the spatial resolution is FWHM=8.0 mm, angular resolution is 3° andγ photon imaging efficiency is 0.38%, which are better than most of the pinhole and coded apertureγ camera imaging.Conclusion： Because of the existence of large amount of data, Compton camera needs long calculation time for measuring data. The next step is improving simulated Compton camera to study its performance parameters, while the maximum likelihood algorithm could improve the spatial resolution of Compton camera.
出处
《核技术》
CAS
CSCD
北大核心
2015年第11期57-62,共6页
Nuclear Techniques
关键词
康普顿相机
蒙特卡罗模拟
反投影图像重建算法
Compton camera
Monte Carlo simulation
Backprojection imaging reconstruction algorithm
