Author:
Zarei H.,Razaghi S.,Nagao Y.,Itoh M.,Yamaguchi M.,Kawachi N.,Ay M.R.,Watabe H.
Abstract
Abstract
In nuclear medicine, the development of portable imaging
devices that provide high imaging resolution and sensitivity,
capable of imaging gamma rays with a wide energy range and multiple
radioisotopes tracing capabilities, is so important. These goals
have been possible thanks to developing a compact Compton camera, a
collimatorless detector coupled to compact silicon
photomultiplier(SiPM) array, using scintillator crystal. In this
study, the portable segmented GAGG:Ce scintillator-based Compton
camera (CC) is optimized with the GATE, a Monte Carlo simulation
toolkit based on Geant4, to maximize its performance for a wide
range of gamma-ray energy (364–1000 keV). The geometrical
parameters are selected as optimization parameters to investigate
their effects on CC's performance, including imaging resolution and
absolute detection efficiency (DE
a
). The geometry parameters of
CC include the planner area of scatterer and absorber detectors,
their thicknesses, and the distance between them. The results for
the energy range of 364–1000 keV show that the most important
contributions to the spatial resolution and DE
a
of the camera
are SAD (scatterer to absorber distance) and the scatterer area
while changing absorber area (AA
) showed the most negligible
impact. In the short SADs, imaging resolution and DE
a
are
significantly affected by the detector's size and thickness. On the
other hand, in the long SADs (> 4 cm), both spatial resolution and
DE
a
are significantly affected by the detector's area but less
affected by the detector's thickness. Decreasing the scatterer's
thickness and the absorber's size or thickness improves imaging
resolution without significantly reducing DE
a
. The simulation
study's findings presented here will provide valuable guidelines for
researchers choosing a desired CC's design according to particular
objectives, manufacturing limitations in scintillator growth, cost,
etc.
Subject
Mathematical Physics,Instrumentation