Department of Biomedical Engineering, University of California Davis, Davis, CA, USA.
Department of Radiology, University of California Davis, Davis, CA, USA.
Med Phys. 2021 Jun;48(6):2800-2808. doi: 10.1002/mp.14863. Epub 2021 Apr 12.
The need for high-fidelity modeling of radiation detectors to perform reliable detector performance optimization using Monte Carlo simulations requires to accurately simulate the light transport in the scintillator and the light collection by the photodetector. In this work, we implement our well-validated crystal reflectance model computed from three-dimensional (3D) crystal surface measurement in a standalone open-source application to allow researchers to generate fully customized crystal reflectance look-up-tables (LUTs) to be used in optical Monte Carlo simulation.
The LUTDavisModel application can be installed in a few minutes on Windows, macOS, and Linux, using 26 MB of space. MATLAB Runtime is required and is automatically installed with the application. The core algorithm has been previously validated experimentally and implemented in GATE v8.0. The standalone is divided into five panels, each of which performing a specific task: generate LUTs from a combination of surface type, scintillator, and coupling medium available in the database (such as LSO or BGO) or custom; compute LUTs with the reflectors available and custom coupling thickness; create a mixture of coupling media to account for possible defects in the optical coupling; plot precomputed LUTs for visual comparison. Tooltips and errors/warnings facilitate the navigation. The reported computational times were obtained with an Intel Core i7 MacBook Pro.
LUTs can be generated with computational time ranging from a few minutes to several hours depending on the selected surface, sampling, and computational power. A longer time is needed when using rough surfaces and thick coupling media (hundreds of ) due to increased photon tracking.
We developed a user-friendly standalone application to generate LUTs that can be used inside GATE Monte Carlo simulations. It can be easily downloaded, installed, and used. Future optimizations will expand the database, decrease the computational time through greater parallelization, and include the generation of LUTs to study Cerenkov photons transport.
为了使用蒙特卡罗模拟进行可靠的探测器性能优化，需要对辐射探测器进行高保真建模，这就需要准确模拟闪烁体中的光传输和光电探测器的光收集。在这项工作中，我们实现了我们经过良好验证的晶体反射率模型，该模型是从三维（3D）晶体表面测量中计算出来的，并将其集成到一个独立的开源应用程序中，以便研究人员生成完全定制的晶体反射率查找表（LUT），用于光学蒙特卡罗模拟。
LUTDavisModel 应用程序可以在 Windows、macOS 和 Linux 上几分钟内安装，占用空间 26MB。需要 MATLAB 运行时，它会随应用程序自动安装。核心算法已经过实验验证，并在 GATE v8.0 中实现。独立版分为五个面板，每个面板执行特定任务：从数据库（如 LSO 或 BGO）或自定义的表面类型、闪烁体和耦合介质组合中生成 LUT；使用可用的反射器和自定义耦合厚度计算 LUT；创建耦合介质的混合物，以说明光学耦合中的可能缺陷；绘制预计算的 LUT 进行视觉比较。工具提示和错误/警告可方便导航。报告的计算时间是在配备 Intel Core i7 MacBook Pro 的情况下获得的。
根据所选表面、采样和计算能力，生成 LUT 的计算时间从几分钟到几个小时不等。当使用粗糙表面和厚耦合介质（数百微米）时，由于光子跟踪增加，所需时间会更长。
我们开发了一个用户友好的独立应用程序来生成可在 GATE 蒙特卡罗模拟中使用的 LUT。它可以轻松下载、安装和使用。未来的优化将扩展数据库，通过更大的并行化减少计算时间，并包括生成 LUT 以研究切伦科夫光子传输。
