Performance Simulation of an Ultrahigh Resolution Brain PET Scanner Using 1.2-mm Pixel Detectors

The concept of a new ultrahigh resolution (UHR) positron emission tomography (PET) brain scanner featuring truly pixelated detectors based on the LabPET II technology is presented. The aim of this paper is to predict the performance of the scanner using geant4 application for tomographic emission simulations. The NEMA procedures for human and small animal PET scanners were used, whenever appropriate, to simulate spatial resolution, scatter fraction, count rate performance, and the sensitivity of the proposed system compared to state-of-the-art PET scanners that would currently be the preferred choices for brain imaging, namely the high-resolution research tomograph dedicated brain PET scanner and the Biograph Vision whole-body clinical PET scanner. The imaging performance was also assessed using the NEMA-NU4 image quality phantom, a mini Hot Spot phantom, and a 3-D voxelized brain phantom. A reconstructed nearly isotropic spatial resolution of 1.3 mm full width at half-maximum is obtained at 10 mm from the center of the field of view. With an energy window of 250-650 keV, the system absolute sensitivity is estimated at 3.4% and its maximum noise equivalent count rate reaches 16.4 kcps at 12 kBq/cc. The simulation results provide evidence of the promising capabilities of the proposed scanner for UHR brain imaging.