Optimizing light transport in scintillation crystals for time-of-flight PET: an experimental and optical Monte Carlo simulation study
Optimizing light transport in scintillation crystals for time-of-flight PET: an experimental and optical Monte Carlo simulation study
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DOI：
10.1364/boe.6.002220
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发表时间：
2015-06-01
影响因子：
3.4
通讯作者：
Cherry, Simon R.
中科院分区：
文献类型：
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作者：
Berg, Eric;Roncali, Emilie;Cherry, Simon R.
在伽马射线探测器中获得良好的时间分辨率在几个应用中是至关重要的，例如使用飞行时间正电子发射断层扫描(TOF-PET)的医学成像。虽然有许多因素影响整个系统的定时分辨率，但闪烁光的统计性质，包括晶体中的光子产生和传输到光电探测器，通常是现代闪烁探测器的限制因素。在这项研究中，我们研究了表面处理，特别是对原本抛光的晶体的选定区域进行粗化对光传输和时间分辨率的影响。一种定制的蒙特卡罗光子跟踪工具被用来洞察实验中观察到的光收集和定时分辨率的变化：与所有抛光表面的晶体相比，精选的粗化配置使光收集增加了25%，定时分辨率提高了15%。模拟表明，部分表面粗化导致更多的光子被反射到光电探测器上，并增加了光电子产生的初始速率。这项研究提供了一种简单的方法来提高基于闪烁体的伽马射线探测器的时间分辨率和光收集能力，这是TOFPET领域的一个非常重要的课题。此外，我们演示了我们的蒙特卡罗模拟工具的实用性，以准确地预测改变晶体表面对光收集和时间分辨率的影响。(C)2015年美国光学学会
Achieving excellent timing resolution in gamma ray detectors is crucial in several applications such as medical imaging with time-of-flight positron emission tomography (TOF-PET). Although many factors impact the overall system timing resolution, the statistical nature of scintillation light, including photon production and transport in the crystal to the photodetector, is typically the limiting factor for modern scintillation detectors. In this study, we investigated the impact of surface treatment, in particular, roughening select areas of otherwise polished crystals, on light transport and timing resolution. A custom Monte Carlo photon tracking tool was used to gain insight into changes in light collection and timing resolution that were observed experimentally: select roughening configurations increased the light collection up to 25% and improved timing resolution by 15% compared to crystals with all polished surfaces. Simulations showed that partial surface roughening caused a greater number of photons to be reflected towards the photodetector and increased the initial rate of photoelectron production. This study provides a simple method to improve timing resolution and light collection in scintillatorbased gamma ray detectors, a topic of high importance in the field of TOFPET. Additionally, we demonstrated utility of our Monte Carlo simulation tool to accurately predict the effect of altering crystal surfaces on light collection and timing resolution. (C) 2015 Optical Society of America