New optical Monte Carlo simulation tools for nuclear medicine

项目摘要/摘要 时间分辨率是当前和未来辐射探测器最重要的特征之一 诊断和治疗成像。在正电子发射断层扫描(PET)中，它的图像质量有了很大的提高 通过飞行时间(TOF)实现质量，分辨率为350-500 ps，允许正电子本地化 湮灭-患者体内活动分布的直接测量，不确定度为5-7.5厘米。 可以进一步提高图像对比度，最终目标是直接重建图像的 正电子湮没通过一个雄心勃勃的目标，10ps的时间分辨率。改进探测器时序 需要对光传输进行彻底的优化，这只能通过精确的蒙特卡罗来实现 模拟。这项提议将为核医学探测器开发精确的光学模拟工具 并将其应用于TOF-PET快速探测器的设计。 开源软件GATE和Geant4构成了核成像的主要仿真平台 和心理治疗。它包括闪烁体中的光学传输，但用于描述光反射的模型 对闪烁体表面的影响是非常不准确的。我们已经开发并集成了一种新的光学系统 模型，即解决这一限制的“LUT Davis模型”。这项工作得到了NIH R03拨款的支持， 论证了精确闪烁体光学建模的可行性，并开启了使用 探测器时序研究的模拟。特别感兴趣的是正在研究的切伦科夫光子 要将时序分辨率提高到10ps，这将需要更先进的仿真工具。 我们将首先开发和免费分发计算工具，以生成定制的光学表面LUT 这一目标预计将对新探测器所在的核成像社区产生重大影响 是为未来几代扫描仪设计的。第二，我们将专门开发光学模型用于 光子计时研究，目标是建立探测器计时的全面模拟框架 优化。第三，我们将应用我们先进的蒙特卡罗模拟工具来优化切伦科夫的使用 用于高性价比BGO TOF PET探测器的光子和开发第一个半导体TOF PET 探测器。通过这些时间研究，我们将解决PET中最重要的挑战之一 研究，这有可能改变PET仪器。

Project Summary/ Abstract Timing resolution is one of the most important features of current and future radiation detectors for diagnostic and therapeutic imaging. In positron emission tomography (PET), it has drastically improved image quality through time-of-flight (TOF) with a resolution of 350-500 ps that allows for the localization of positron annihilations– a direct measure of the activity distribution in the patient, with an uncertainty of 5-7.5 cm. Further improvement in image contrast could be obtained, with the ultimate goal of directly reconstructing the positron annihilation through an ambitious target of 10 ps timing resolution. Improving the detector timing requires the light transport to be thoroughly optimized, which can only be done through accurate Monte Carlo simulation. This proposal will develop accurate optical simulation tools for nuclear medicine detectors and will apply them to the design of fast detectors for TOF PET. The opensource software GATE and Geant4 constitute the main simulation platform in nuclear imaging and therapy. It includes optical transport in scintillators, but the models used to describe the light reflecting on the scintillator surfaces are highly inaccurate. We have developed and integrated into GATE a new optical model, the “LUT Davis model” that addresses this limitation. This work, supported by an NIH R03 grant, demonstrated the feasibility of accurate scintillator optical modeling and opened the possibilities of using simulations for detector timing studies. Of particular interest are Cerenkov photons that are being investigated to improve timing resolution as low as 10 ps, which will require more advanced simulation tools. We will first develop and freely distribute computational tools to generate custom optical surface LUTs This aim is expected to have a strong impact on the nuclear imaging community where new detectors are being designed for future generations of scanners. Second, we will specifically develop optical models for photon timing studies, with the goal of establishing a comprehensive simulation framework for detector timing optimization. Third, we will apply our advanced Monte Carlo simulation tools to optimize the use of Cerenkov photons for a cost-effective BGO TOF PET detector and to develop the first semiconductor TOF PET detector. With these timing studies, we will tackle one of the most important challenges in PET research, which has the potential to transform PET instrumentation.