  Organ-specific, targeted Field-of-View (FoV) Positron Emission Tomography
(PET)/Magnetic Resonance Imaging (MRI) inserts are viable solutions for a
number of imaging tasks where whole-body PET/MRI systems lack the necessary
sensitivity and resolution. To meet the required PET detector performance of
these systems, high count-rates and effective spatial resolutions on the order
of a few mm, a novel two-axis patterned reflector foil pixelated scintillator
crystal array design is developed and its proof-of-concept illustrated
in-silico with the Monte Carlo radiation transport modelling toolkit Geant4. It
is shown that the crystal surface roughness and phased open reflector
cross-section patterns could be optimised to maximise either the PET radiation
detector's effective spatial resolution, or count rate before event pile up. In
addition, it was illustrated that these two parameters had minimal impact on
the energy and time resolution of the proposed PET radiation detector design.
Finally, it is shown that a PET radiation detector with balance performance
could be constructed using ground crystals and phased open reflector
cross-section pattern corresponding to the middle of the tested range.
