Multi-Parameter Optimization and Imaging Performance Evaluation of a 16 × 1 Ce:GAGG Linear Scintillator Detector: A Monte Carlo Simulation Study

Ce:GAGG linear scintillator detectors are promising for high-resolution radiation imaging, but signal sharing near pixel boundaries can affect position resolution. A Geant4 model of a 16 × 1 array was used to assess the lateral pixel dimension (PT), reflector thickness (REF), reflector material, metal interlayer and anti-scatter grid (ASG). The Gaussian-equivalent full width at half maximum (FWHM) of the reconstructed-position distribution and the spatial frequency at 50% modulation transfer (MTF50) were evaluated at central and boundary irradiation positions. PT = 1.0 mm, REF = 0.3 mm and MgO gave a favorable balance between central and boundary responses; the metal interlayer had little influence. A W ASG with 0.60 mm bars and a height of 5.0 mm was selected by comparing total and neighboring-channel energy-deposition tallies in a scattering-phantom geometry. Relative to the reference configuration, the phase-integrated adjacent-channel optical-response fraction decreased from 13.66% to 1.53%, the slanted-edge 10–90% width decreased from 2.951 to 1.876 mm, and the imaging MTF50 point estimate increased from 0.163 to 0.256 cycles mm−1. The integrated recorded optical-photon count decreased by 47.2%. In an ASG-free optical comparison, bar-pattern modulation increased from 0.361 to 0.668. The numerical results apply to the specified simulation and scoring conditions.