Raylman Raymond R, Stolin Alexander V, Jaliparthi Gangadhar, Martone Peter F
Center for Advanced Imaging, Department of Radiology, One Medical Center Dr, Box 9236, West Virginia University, Morgantown, WV 26506, United States of America.
Phys Med Biol. 2025 Apr 8;70(8):085001. doi: 10.1088/1361-6560/adc537.
In the past several decades, numerous positron emission tomography (PET) scanners of various designs have been constructed for use in pre-clinical studies. Our group is investigating use of a monolithic annulus of scintillator, instead of the traditional arrays of discrete scintillator elements or individual detectors that utilize continuous blocks of scintillator, to construct a novel pre-clinical PET scanner.This scanner, called AnnPET, is based on a fourteen-faceted annulus of lutetium yttrium orthosilicate with an inner diameter of 6 cm and length of 7.2 cm. Each facet is populated with four specially constructed 4 × 4 arrays of 4 mm × 4 mm multi-pixel photon counters .To cool and temperature stabilize these devices, the scanner gantry is immersed in dielectric fluid. Positioning of events in the scintillator is accomplished with the application of deep-residual convolutional neural network. The scanner's performance was assessed using the NEMA NU4-2008 protocols.Full-width-at-half-maximum (FWHM) of the images of a point source reconstructed with the single slice rebinned filtered backprojection (SSRB-FBP) algorithm at 5 mm from the center of the scanner are: 1.40 mm (radial), 1.38 mm (tangential) and 1.40 mm (axial). At 18 mm from scanner center (edge of the scanner's inner bore) the FWHMs are: 1.62 mm (radial), 1.43 mm (tangential) and 1.48 mm (axial) FWHM. Peak detection sensitivity is 9.5% (0.086 cps Bq). Peak noise equivalent count rate is 234 kcps at 14.4 MBq.Overall, testing of the AnnPET system demonstrated very promising performance results for a pre-clinical PET scanner based on a single, cooled annulus of monolithic scintillator used with neural networks. Continued development of the system is planned.
在过去几十年里，人们制造了许多不同设计的正电子发射断层扫描（PET）扫描仪用于临床前研究。我们团队正在研究使用整块闪烁体环，而非传统的离散闪烁体元件阵列或使用连续闪烁体块的单个探测器，来构建一种新型的临床前PET扫描仪。这种扫描仪名为AnnPET，它基于一个内径6厘米、长度7.2厘米的十四面硅酸钇镥整块环。每个面都装有四个特别构建的4×4阵列的4毫米×4毫米多像素光子计数器。为了冷却并稳定这些设备的温度，扫描仪机架被浸没在介电流体中。利用深度残差卷积神经网络来确定闪烁体中事件的位置。使用NEMA NU4 - 2008协议对扫描仪的性能进行了评估。使用单切片重新分箱滤波反投影（SSRB - FBP）算法在距扫描仪中心5毫米处重建的点源图像的半高全宽（FWHM）为：1.40毫米（径向）、1.38毫米（切向）和1.40毫米（轴向）。在距扫描仪中心18毫米（扫描仪内孔边缘）处，FWHM分别为：1.62毫米（径向）、1.43毫米（切向）和1.48毫米（轴向）。峰值探测灵敏度为9.5%（0.086 cps/Bq）。在14.4 MBq时的峰值噪声等效计数率为234 kcps。总体而言，AnnPET系统的测试表明，对于基于单个冷却的整块闪烁体环并与神经网络配合使用的临床前PET扫描仪，其性能结果非常有前景。计划对该系统继续进行开发。
