Modeling, simulation, and evaluation of a compton camera based on a pixelated solid-state detector

A novel Compton camera design based on pixelated solid-state detectors is proposed and evaluated via Monte Carlo simulation, using the Geant4-based Architecture for Medicine-Oriented Simulations GAMOS. For the image reconstruction, the Stochastic Origin Ensemble (SOE) method has been used. The efficiency of the reconstruction of Compton prompt events is constant up to activities of 10⁷ Bq. The signal-to-noise ratio (SNR), i.e., the ratio between real coincidences and mis-reconstructed ones, was above 85% for photon energies ranging from 141 to 511 keV. For a ¹⁸F isotope source, a sensitivity of 12 cps/kBq has been obtained. For a ^99mTc isotope source, a sensitivity of 15 cps/kBq has been obtained. Using the NEMA NU-4 2008 standard for the PSF estimation, values for the FWHM of 1.80 mm for the spatial resolution with a ¹⁸F radioactive source and 3.82 mm with a ^99mTc source were obtained.