Comparative study of luminescence properties of LuYAP:Ce and LYSO:Ce single-crystal scintillators for use in medical imaging

The luminescence properties of Lu0.7Y0.3AlO3:Ce (LuYAP:Ce) and (Lu0.9,Y0.1)2SiO5:Ce (LYSO:Ce) crystals were studied for use in medical X-ray imaging. LuYAP:Ce and LYSO:Ce are single-crystal scintillators of high density, non-hygroscopic, high light yield and short decay time. The two cerium doped crystals have dimensions of 2×2×8 mm3 with all surfaces polished. Evaluation was performed by determining the absolute luminescence efficiency (emitted light flux over incident X-ray exposure) in X-ray energies employed in general medical X-ray imaging (40–140 kVp) and in mammographic X-ray imaging (22–49 kV). Additionally, the light emission spectrum at various X-ray energies was measured in order to determine the spectral compatibility to optical photon detectors, incorporated in medical imaging systems. The optical characteristics, such as emission spectra, were investigated and important correlations with the scintillation properties were pointed out. The light emission performance of the two scintillation materials studied was found adequately high for medical X-ray imaging.