Predicting the timing properties of phosphor-coated scintillators using Monte Carlo light transport simulation.
Predicting the timing properties of phosphor-coated scintillators using Monte Carlo light transport simulation.
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DOI：
10.1088/0031-9155/59/8/2023
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发表时间：
2014-04-21
影响因子：
3.5
通讯作者：
Cherry SR
中科院分区：
文献类型：
--
作者：
Roncali E;Schmall JP;Viswanath V;Berg E;Cherry SR
目前正电子发射断层扫描（PET）的发展主要集中在提高具有飞行时间（TOF）能力的扫描仪的定时性能，并结合相互作用深度（DOI）信息。最近的研究表明，在TOF探测器中加入DOI校正可以提高时间分辨率，并且DOI在长轴向视场扫描仪中也变得更加重要。我们以前报道过使用磷涂层闪烁晶体开发的doi编码探测器；在这里，我们研究了这些晶体的时序特性，以评估在不显著降低时序性能的情况下提供一定程度的DOI信息的可行性。我们使用蒙特卡罗模拟提供了磷包覆晶体中光传输的详细理解，这在实验中不能完全表征。我们的模拟使用了基于三维晶体表面测量的自定义反射模型。用与闪烁体表面接触的荧光粉涂层和外部漫反射器（聚四氟乙烯）模拟了氧化硅酸镥（LSO）晶体。光输出、能量分辨率和脉冲形状与3 × 3 × 10 mm3晶体耦合到光电倍增管（PMT）上获得的实验数据非常吻合。对闪烁体的内禀时间分辨率进行了正面和侧面的模拟，证实了实验观察到的趋势。这些结果表明，该模型可用于预测磷涂层晶体的时序特性，并指导涂层在给定晶体几何形状下实现最佳DOI分辨率/时序性能权衡。模拟数据表明，由早期光电子产生的时间戳最小化了时间分辨率的退化，因此使得该方法对于TOF-DOI探测器可能比我们最初的实验表明的更有用。最后，这种方法可以很容易地扩展到其他闪烁晶体的定时特性的研究，通过一系列的处理和材料附着在表面。
Current developments in positron emission tomography (PET) focus on improving timing performance for scanners with time-of-flight (TOF) capability, and incorporating depth-of-interaction (DOI) information. Recent studies have shown that incorporating DOI correction in TOF detectors can improve timing resolution, and that DOI also becomes more important in long axial field-of-view scanners. We have previously reported the development of DOI-encoding detectors using phosphor-coated scintillation crystals; here we study the timing properties of those crystals to assess the feasibility of providing some level of DOI information without significantly degrading the timing performance. We used Monte Carlo simulations to provide a detailed understanding of light transport in phosphor-coated crystals which cannot be fully characterized experimentally. Our simulations used a custom reflectance model based on 3D crystal surface measurements. Lutetium oxyorthosilicate (LSO) crystals were simulated with a phosphor coating in contact with the scintillator surfaces and an external diffuse reflector (teflon). Light output, energy resolution, and pulse shape showed excellent agreement with experimental data obtained on 3 × 3 × 10 mm3 crystals coupled to a photomultiplier tube (PMT). Scintillator intrinsic timing resolution was simulated with head-on and side-on configurations, confirming the trends observed experimentally. These results indicate that the model may be used to predict timing properties in phosphor-coated crystals and guide the coating for optimal DOI resolution/timing performance trade-off for a given crystal geometry. Simulation data suggested that a time stamp generated from early photoelectrons minimizes degradation of the timing resolution, thus making this method potentially more useful for TOF-DOI detectors than our initial experiments suggested. Finally, this approach could easily be extended to the study of timing properties in other scintillation crystals, with a range of treatments and materials attached to the surface.
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影响因子：
3.5
作者：
Yeom JY;Vinke R;Levin CS
通讯作者：
Levin CS
DOI：
10.1016/j.nima.2010.03.165
发表时间：
2010-09-01
影响因子：
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作者：
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影响因子：
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作者：
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通讯作者：
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DOI：
10.1016/j.nima.2008.05.020
发表时间：
2008-08-11
影响因子：
1.4
作者：
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通讯作者：
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影响因子：
3.5
作者：
Roncali E;Cherry SR
通讯作者：
Cherry SR