Luminescence Properties of (Lu,Y) sub(2)SiO sub(5):Ce and Gd sub(2)SiO sub(5):Ce Single Crystal Scintillators Under X-Ray Excitation for Use in Medical Imaging Systems

• Published in: IEEE transactions on nuclear science 2007-01, Vol.54 (1)
• Main Authors: Ioannis G. Valais, Ioannis GValais, Ioannis S. Kandarakis, Ioannis SKandarakis, Dimitris N. Nikolopoulos, Dimitris NNikolopoulos, Christos M. Michail, Christos MMichail, Stratos L. David, Stratos LDavid, George K. Loudos, George KLoudos, Dionisis A. Cavouras, Dionisis ACavouras, George S. Panayiotakis, George SPanayiotakis
• Format: Article
• Language: English
• Subjects: Compatibility; Detectors; Flux; Imaging; Luminescence; Medical imaging; Photocathodes; X-rays
• ISSN: 0018-9499
• DOI: 10.1109/TNS.2006.888813

The luminescence of (Lu,Y) sub(2)SiO sub(5) : Ce (LYSO:Ce) and Gd sub(2)SiO sub(5):Ce (GSO:Ce) crystals was studied for use in tomographic medical x-ray imaging. LYSO:Ce and GSO:Ce are high density (7.1 g/cm super(3) and 6.71 g/cm super(3) respectively), high atomic number (71 for Lu and 64 for Gd), non-hydroscopic, and short decay time (40 ns and 60 ns respectively) scintillators. Evaluation was performed by determining: 1) the luminescence efficiency (LE) (emitted light energy flux over incident x-ray energy flux) in x-ray energies employed in general x-ray imaging (40-140 kVp) and in mammographic x-ray imaging (22-49 kVp), 2) the light emission spectrum, determined at various x-ray energies (22-140 kVp), and 3) the spectral compatibility to optical photon detectors, incorporated in medical imaging systems. Both scintillation materials exhibited adequately high LE in the x-ray diagnostic energy range, with LYSO:Ce's LE being distinctively higher. LYSO:Ce and GSO:Ce were found most compatible with the S-20 photocathode (0.9 for both materials) and adequately compatible to the amorphous silicon photodiode (0.74 for both materials), incorporated in many digital x-ray detectors