Investigation of LaBr3:Ce and LaCl3:Ce scintillators for spect imaging

This study aims to investigate the potential use of LaBr₃:Ce and LaCl₃:Ce materials in SPECT imaging. GATE Monte Carlo simulations of single-head gamma camera and a ⁹⁹Tc^m point source were performed to evaluate the energy spectra, modulation transfer function (MTF) and detection efficiency. A range of Ce concentrations (0.5, 5, 10 and 15)% of LaBr₃:Ce and LaCl₃:Ce crystals was simulated in conjunction with efficiency calculation to find optimal concentration for SPECT imaging. The MTF curves showed the excellent MTF performance of LaCl₃ and LaBr₃ particularly at low frequencies. The intrinsic efficiency results demonstrated the superiority of LaBr₃:Ce crystals with respect to LaCl₃:Ce and Nal(Tl). Results also suggest that higher Ce concentrations for both LaBr₃:Ce and LaCl₃:Ce crystals only slightly improve intrinsic efficiency. In conclusion, because LaCl₃:Ce and LaBr₃:Ce combine excellent MTF performance with increased intrinsic efficiency, they have the potential to replace Nal(Tl) as the scintillators of choice for SPECT.