The Monte Carlo method is an effective tool to simulate and verify PET systems. Furthermore, it can help in the design and optimization of new medical imaging devices and algorithms. In this framework, the goal of this work is to verify the GATE toolkit performance when applied to simulate two Siemens Healthineers PET scanners: a standard axial field-of-view Biograph Vision scanner and the new long axial field-of-view Biograph Vision Quadra scanner. The simulation toolkit GATE is based on GEANT4, comprising its main functionalities and a set of domain-specific features in the field of medical physics. To accomplish our purpose, the guidelines described in the NEMA NU 2-2018 protocol are reproduced. Then the simulated results are compared to experimental data available in the literature for both PET scanners. The assessment of the models includes different studies of sensitivity, count rate performances, spatial resolution and image quality. These tests are intended to evaluate the image quality of PET devices. In the spatial resolution test, relative errors lower than 8% are obtained between the experiments and GATE models. The sensitivity is 17.2 cps/kBq (Vision) and 175.9 cps/kBq (Quadra), representing relative differences with the experiment of 6% and 0.3%, respectively. Deviations from peak NECR are less than 9%. In the Image Quality test, the contrast recovery coefficient for hot spheres, with 8 iterations and 5 subsets, ranges between 57–83% for Vision and 54–86% for Quadra. These values represent a maximum deviation between the simulations and the experiments of 10% for the Quadra scanner. In the case of the Vision scanner, the highest difference is observed for the 10 mm sphere (∼38%) due to the higher contrast recovery of the experiment caused by the Gibbs artifact from the use of PSF reconstruction. The results of the simulations have provided evidence of a good agreement between the experimental data and the results obtained with GATE. Thus, this work supports the capability of this MC toolkit to accurately simulate the models of the Vision and Quadra scanners. This study has laid the basis for further research in this field and has identified several areas that could be explored.

中文翻译：

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应用 NEMA 协议验证基于 Digital Biograph Vision 和 Biograph Vision Quadra 扫描仪的 GATE 模型

蒙特卡罗方法是模拟和验证 PET 系统的有效工具。此外，它可以帮助设计和优化新的医学成像设备和算法。在此框架中，这项工作的目标是验证 GATE 工具包在模拟两台西门子 Healthineers PET 扫描仪时的性能：标准轴向视场 Biograph Vision 扫描仪和新型长轴向视场 Biograph Vision Quadra扫描器。模拟工具包 GATE 基于 GEANT4，包含其主要功能和一组医学物理领域的特定功能。为了实现我们的目的，复制了 NEMA NU 2-2018 协议中描述的指南。然后将模拟结果与文献中提供的两种 PET 扫描仪的实验数据进行比较。模型的评估包括对灵敏度、计数率性能、空间分辨率和图像质量的不同研究。这些测试旨在评估 PET 设备的图像质量。在空间分辨率测试中，实验与GATE模型的相对误差低于8%。灵敏度为 17.2 cps/kBq (Vision) 和 175.9 cps/kBq (Quadra)，与实验的相对差异分别为 6% 和 0.3%。与峰值 NECR 的偏差小于 9%。在图像质量测试中，经过 8 次迭代和 5 个子集的热球的对比度恢复系数，Vision 的范围为 57-83%，Quadra 的范围为 54-86%。这些值表示 Quadra 扫描仪的模拟与实验之间的最大偏差为 10%。在视觉扫描仪的情况下，由于使用 PSF 重建产生的吉布斯伪影导致实验的对比度恢复较高，因此在 10 mm 球体上观察到最高差异（∼38%）。模拟结果证明实验数据与 GATE 获得的结果之间具有良好的一致性。因此，这项工作支持该 MC 工具包准确模拟 Vision 和 Quadra 扫描仪模型的能力。这项研究为该领域的进一步研究奠定了基础，并确定了几个可以探索的领域。