Title :
Imaging performances of LaCl3:Ce scintillation crystals in SPECT
Author :
Pani, R. ; Cinti, M.N. ; De Notaristefani, F. ; Pellegrini, R. ; Bennati, P. ; Betti, M. ; Trotta, G. ; Karimian, A. ; Mattioli, Mauro ; Garibaldi, F. ; Cusanno, F. ; Cencelli, Orsolini
Author_Institution :
Dept. of Exp. Med. & Pathology, INFN, Rome, Italy
Abstract :
Over the last three years, there is a growing interest in the development of a new class of fast scintillators like LaCl3:Ce and LaBr3:Ce. The new scintillation crystals for the first time, have the main characteristic in producing a light photon number higher than NaI(Tl) at a wavelength suited for the photocathode. The most important characteristic of these crystals is represented from the scintillation light to be yield proportionality as a function of incident gamma ray energy. With the aim to investigate on their potential in single photon imaging three one inch square LaCl3:Ce continuous scintillation crystals with 3 and 6 mm thickness were specifically designed for position measurements. They have been coupled to a flat panel PMT through a 3 mm thickness glass window. In order to highlight all the characteristics of the detection system the third one, 3 mm thick, was integral assembled with a one inch PSPMT Hamamatsu R5900-C8. Free and collimated point radioactive sources were used for energy resolution measurements as well for scanning crystals to investigate spatial resolution and position response. Energy resolution values were compared with ones obtained from a sample of LaBr3:Ce with one inch diameter and one thickness designed for spectrometric measurements. LaCl3:Ce with 3 mm thickness shown energy resolution values worse than expected (13% at 140 KeV) due to the sub-optimal size and configuration for light collection. On the contrary LaBr3:Ce carried out 6% relative energy resolution at 140 keV. Intrinsic spatial resolution values of 1 mm and 1.3 mm were obtained from 3 mm thickness LaCl3:Ce crystals in the two configurations investigated.
Keywords :
nuclear electronics; photocathodes; single photon emission computed tomography; solid scintillation detectors; LaBr3:Ce; LaCl3:Ce scintillation crystals; NaI(Tl); SPECT; energy resolution measurements; gamma ray energy; imaging performances; light photon number; photocathode; radioactive sources; scanning crystals; scintillators; spatial resolution; Cathodes; Energy measurement; Energy resolution; Glass; Optical imaging; Photonic crystals; Position measurement; Solid scintillation detectors; Spatial resolution; Windows;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2004 IEEE
Print_ISBN :
0-7803-8700-7
DOI :
10.1109/NSSMIC.2004.1462715