High spatial and energy resolution gamma imaging based on LaBr3(Ce) continuous crystals

R. Pani, F. Vittorini, R. Pellegrini, P. Bennati, M.N. Cinti, M. Mattioli, R. Scafè, S. Lo Meo, F. Navarria, G. Moschini, P. Boccaccio, V. Orsolini Cencelli, F. De Notaristefani

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25 Citations (Scopus)

Abstract

Recently scintillators with very high light yield and photodetectors with high quantum efficiency have been opening a new way to realize gamma cameras with superior performances based on continuous crystals. Pixilated imagers have a spatial resolution limited by pixel size, in contrast with continuous scintillation crystals, where spatial resolution is a statistical function depending on light distribution spread and on generated photoelectrons from scintillation light flash. Continuous LaBr3:Ce crystal, with a light yield almost two times higher than NaI:Tl ones and a lower intrinsic energy resolution, could be the best candidate to carry out a gamma imaging with sub-millimeter spatial resolution and very good energy resolution. Unfortunately standard Anger algorithm produces an intrinsic position non-linearity affecting spatial resolution for small size continuous crystal. In this work we propose a new method to calculate the position mean value by squaring the 2D collected charge distribution on a multi-anodes photomultiplier tube (MA-PMT). In this study we take into account four different detector configurations: three sample of LaBr3:Ce scintillation crystals, 49mm×49mm area, a couple of 4.0 with different surface treatment and a single 10 mm thick, with 3 mm glass window. Moreover a forth one with 5.0mm thickness which was integral assembled with an Hamamatsu H8500. We applied the new position algorithm to simulated data, obtained by Geant4 code and afterwards to the experimental data obtained scanning the different detectors with 0.4 mm Ø collimated Tc 99M" point source, at 1.5 mm step. The results obtained with the new algorithm show an improvement in position linearity and in spatial resolution of about a factor two. The best values in terms of spatial resolution were 0.9 mm, 1.1 mm and 1.8 mm for integral assembled, 4.0 mm thick and 10 mm thick LaBr3:Ce crystal respectively. These results demonstrate the potential of LaBr crystal for molecular imaging application and more in general for gamma ray imaging. © 2008 IEEE.
Original languageEnglish
DOIs
Publication statusPublished - 2008
Externally publishedYes
Event2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008 - , Germany
Duration: 1 Jan 2008 → …

Conference

Conference2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008
CountryGermany
Period1/1/08 → …

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All Science Journal Classification (ASJC) codes

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging

Cite this

Pani, R., Vittorini, F., Pellegrini, R., Bennati, P., Cinti, M. N., Mattioli, M., ... De Notaristefani, F. (2008). High spatial and energy resolution gamma imaging based on LaBr3(Ce) continuous crystals. Paper presented at 2008 IEEE Nuclear Science Symposium Conference Record, NSS/MIC 2008, Germany. https://doi.org/10.1109/NSSMIC.2008.4775116