Image reconstruction using multi-energy system matrices with a scintillator-based gamma camera for nuclear security applications
Image reconstruction using multi-energy system matrices with a scintillator-based gamma camera for nuclear security applications
复制标题
使用多能量系统矩阵和基于闪烁体的伽马相机进行图像重建，用于核安全应用
DOI：
10.1016/j.apradiso.2020.109217
复制
发表时间：
2020-09-01
影响因子：
1.6
通讯作者：
Zhu, Tao
中科院分区：
文献类型：
--
作者：
Liu, Qi;Cheng, Yi;Zhu, Tao
伽马相机的系统响应取决于光子能量，因此需要考虑与能量相关的响应函数，以提高重建图像的质量和保真度，以识别安全应用中的放射性核素。在本研究中，提出了两种使用最大似然期望最大化（MLEM）算法和蒙特卡罗模拟计算的多能量系统矩阵的重建策略。两者的区别在于数据采集；一种将所有事件的总和放入单个投影图像中，而另一种将它们分类到单独的能量窗口中。使用蒙特卡罗代码模拟伽马射线源的各种辐射图像，并使用伽马相机获取实际图像。仿真和实验结果都证明了所提出的多能量重建策略在孤立源检测中的可行性。
The system response of a gamma camera is dependent on the photon energy, thus the energy-dependent response function needs to be considered to improve the quality and fidelity of reconstructed images for identifying radionuclides in security applications. In this study, two reconstruction strategies using the maximum-likelihood expectation maximization (MLEM) algorithm with the multi-energy system matrices calculated by Monte Carlo simulations are proposed. The difference between the two is in data acquisition; one uses the sum of all events into a single projection image while the other sorts them into separate energy windows. Various radiation images of gamma-ray sources were simulated with a Monte Carlo code, and an actual image was acquired with a gamma camera. Both simulation and experiment results demonstrated the feasibility of the presented multi energy reconstruction strategies in the detection of orphan sources.