GATE Monte Carlo simulation of a high-sensitivity and high-resolution LSO-based small animal PET camera
GATE Monte Carlo simulation of a high-sensitivity and high-resolution LSO-based small animal PET camera
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DOI：
10.1109/tns.2007.905165
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发表时间：
2007-10-01
影响因子：
1.8
通讯作者：
Wong, Wai-Hoi
中科院分区：
文献类型：
--
作者：
Baghaei, Flossain;Zhang, Yuxuan;Wong, Wai-Hoi
在本文中，我们描述了具有大轴向视场（AFOV）的高灵敏度、高分辨率小动物正电子发射断层扫描（PET）扫描仪性能的蒙特卡罗模拟。模拟相机基于光电倍增象限共享 (PQS) 概念，由 180 块 14 x 14 氧原硅酸镥 (LSO) 晶体组成，每个晶体的横轴尺寸为 1.16 mm，横轴尺寸为 1.27 nun，径向尺寸为 9.4 nun。该相机有 84 个探测器环，AFOV 为 11.6 cm，环直径为 16.6 cm。对于模拟，我们使用 Geant4 应用层析发射 (GATE) 模拟包。我们通过比较 GATE 对空间分辨率、绝对灵敏度和计数率的预测与使用现有的基于锗酸铋 (BGO) 的专用动物 PET 扫描仪获得的测量数据来验证 GATE，该扫描仪具有相似的 AFOV 和环直径，并且基于 PQS 技术。还对 Data Spectrum Micro Deluxe 体模的模拟图像和实验图像进行了比较。模拟数据表明，基于 LSO 的新型扫描仪可以重建中心处的径向（切向）空间分辨率分别为 1.14 毫米（1.14 毫米）、1.31 毫米（1.32 毫米）、1.54 毫米（1.52 毫米）、2.01 毫米（1.8 毫米）和 2.4 毫米（2.1 毫米），偏离中心的位置分别为 1 厘米、2 厘米、3 厘米和 4 厘米。模拟数据还表明，Micro Deluxe 模型中的 1.2 毫米热棒将是可区分的。假设能量窗口为 300 keV 至 750 keV、重合时间窗口为 8 ns、系统死区时间为 60 us，仿真预测相机中心点源的绝对灵敏度约为 7.3%。
In this paper, we describe a Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal positron emission tomography (PET) scanner with a large axial field-of-view (AFOV). The simulated camera is based on the photomultiplier-quadrant-sharing (PQS) concept and composed of 180 blocks of 14 x 14 lutetium oxyorthosilicate (LSO) crystals each measuring 1.16 mm transaxially, 1.27 nun transaxially, and 9.4 nun radially. The camera has 84 detector rings with an 11.6 cm AFOV and a ring diameter of 16.6 cm. For the simulation, we used the Geant4 Application for Tomographic Emission (GATE) simulation package. We validated GATE by comparing its predictions for spatial resolution, absolute sensitivity, and count rate with measured data obtained using an existing bismuth germanate (BGO) based dedicated animal PET scanner that had a similar AFOV and ring diameter and was based on the PQS technique. Simulated and experimental images of the Data Spectrum Micro Deluxe phantom were also compared. The simulation data suggested that new LSO-based scanner could have reconstructed radial (tangential) spatial resolutions of 1.14 mm (1.14 mm), 1.31 nun (1.32 mm), 1.54 mm (1.52 mm), 2.01 mm (1.8 mm), and 2.4 mm (2.1 mm) at the center and 1 cm, 2 cm, 3 cm, and 4 cm off center, respectively. The simulation data also suggested that 1.2-mm hot rods in the Micro Deluxe phantom will be distinguishable. Simulation predicted an absolute sensitivity of about 7.3 % for a point source at the center of the camera assuming an energy window of 300 keV to 750 keV, a coincidence time window of 8 ns, and a system dead time of 60 us.