Structural Design And Monte Carlo Simulation Analysis Of Polyhedral Brain Dedicated PET

Positron emission tomography(PET)imaging can represent the biological tissue metabolism at the molecular level,which has important value in the early diagnosis and prognosis of tumors and some other psychiatric research like Alzheimer's.While traditional medical human PET was mainly designed for whole-body detection,thus might result in a series of problems such as low image resolution,large regional resolution difference and long detection time when applied to brain imaging.A polygonal structure brain dedicated PET was proposed based on the original concept to meet the increasing demand with its structural design and imaging simulation being studied.The compact open-close mechanical structure and polygonal detector were designed and optimized.Results demonstrated that its geometric sensitivity was much higher than that of the traditional small diameter ring structure PET.GATE is the most widely used simulation platform for Monte Carlo simulation of emission tomography.The model of the polyhedral structure system was constructed.Location information reconstruction of single photon events verified the correctness of the system structure.The coincidence events were extracted from single photon events by self-programming due to the irregular structure.The events statistics of multi-sequence points indicated that significantly higher system sensitivity was achieved by the polyhedral structure compared to traditional small ring PET.The top region of the brain could also maintain high sensitivity,meaning that whole brain imaging could be achieved during one detection without moving.Based on the SSRB data reorganization,the FBP algorithm and the MLEM algorithm were applied respectively to reconstruct the standard Micro-Derenzo phantom and the Hoffman phantom.The reconstructed images verified the polyhedral structure PET system's capability of tomography and multi-zone uniform imaging.According to the NEMA standard,some parameters such as spatial resolution,equivalent noise count rate and scattering fraction were also evaluated.The spatial resolution at the center of FOV was better than the small ring PET.Polygon structure brain dedicated PET system has a prominent advantage in the field of brain imaging,expected to make an important contribution to clinical diagnosis and research of brain diseases.