Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland.
Phys Med Biol. 2018 Aug 10;63(16):165008. doi: 10.1088/1361-6560/aad29b.
A novel whole-body positron emission tomography (PET) system based on plastic scintillators is developed by the J-PET Collaboration. It consists of plastic scintillator strips arranged axially in the form of a cylinder, allowing the cost-effective construction of the total-body PET system. In order to determine the properties of the scanner prototype and optimize its geometry, advanced computer simulations were performed using the GATE (Geant4 application for tomographic emission) software. The spatial resolution, sensitivity, scatter fraction and noise equivalent count rate were estimated according to the National Electrical Manufacturers Association norm, as a function of the length of the tomograph, the number of detection layers, the diameter of the tomographic chamber and for various types of applied readout. For the single-layer geometry with a diameter of 85 cm, a strip length of 100 cm, a cross-section of 4 mm × 20 mm and silicon photomultipliers with an additional layer of wavelength shifter as the readout, the spatial resolution (full width at half maximum) in the centre of the scanner is equal to 3 mm (radial, tangential) and 6 mm (axial). For the analogous double-layer geometry with the same readout, diameter and scintillator length, with a strip cross-section of 7 mm × 20 mm, a noise equivalent count rate peak of 300 kcps was reached at 40 kBq cc activity concentration, the scatter fraction is estimated to be about 35% and the sensitivity at the centre amounts to 14.9 cps kBq. Sensitivity profiles were also determined.
由 J-PET 合作组织开发了一种基于塑料闪烁体的新型全身正电子发射断层扫描（PET）系统。它由轴向排列的塑料闪烁体条组成，形成一个圆柱体，允许以具有成本效益的方式构建全身 PET 系统。为了确定扫描仪原型的特性并优化其几何形状，使用 GATE（用于发射断层扫描的 Geant4 应用程序）软件进行了先进的计算机模拟。根据美国国家电气制造商协会的规范，根据断层的长度、检测层的数量、断层室的直径以及各种类型的应用读出方式，估计了空间分辨率、灵敏度、散射分数和噪声等效计数率。对于直径为 85 cm、条长为 100 cm、横截面为 4 mm × 20 mm 且硅光电倍增管带有附加的波长移位器作为读出的单层几何形状，在扫描仪中心的空间分辨率（半最大值全宽）等于 3 mm（径向、切向）和 6 mm（轴向）。对于具有相同读出、直径和闪烁体长度的类似双层几何形状，条横截面为 7 mm × 20 mm，在 40 kBq cc 活性浓度下达到 300 kcps 的噪声等效计数率峰值，估计散射分数约为 35%，中心灵敏度达到 14.9 cps kBq。还确定了灵敏度分布。
