Resolution and sensitivity improvement in positron emission tomography by the first interaction point determination

Abstract

Resolution loss of positron emission tomography (PET) caused by photon scattering and penetration is analyzed, and a novel 2-D detector scheme and associated detection algorithm are proposed to correct the effect of scattering and penetration, thereby improving resolution as well as sensitivity. The errors in coincidence line assignment due to photon scattering and penetration are computed using Monte Carlo simulation, and the resulting image blur is examined. The error in the coincidence line assignment and resulting image blur can be corrected by forming the coincidence line between the first interaction points (FIPs). The optimum algorithm for the determination of the FIP is derived using mathematical models of photon interactions in scintillation detectors. Simulation studies show the feasibility of developing entirely new lines of ultrahigh-resolution brain PET which also possess high sensitivity.