Investigation on a small FoV gamma camera based on LaBr3:Ce continuous crystal

Recently scintillating crystals with high light yield coupled to photodetectors with high quantum efficiency have been opening a new way to make gamma cameras with superior performances based on continuous crystals. In this work we propose the analysis of a gamma camera based on a continuous LaBr(3):Ce crystal coupled to a multi-anodes photomultiplier tube (MA-PMT.). In particular we take into account four detector configurations, different in crystal thicknesses and assembling. We utilize a new position algorithm to reduce the position non linearity affecting intrinsic spatial resolution of small FoV gamma cameras when standard Anger algorithm is applied. The experimental data are obtained scanning the detectors with 0.4 mm collimated (99m)Tc source, at 1.5 mm step. An improvement in position linearity and spatial resolution of about a factor two is obtained with the new algorithm. The best values in terms of spatial resolution were 0.90 mm, 0.95 mm and 1.80 mm for integral assembled, 4.0 mm thick and 10 mm thick LaBr(3):Ce crystal respectively

LaBr3:Ce Scintillation Imagers Optimization by GEANT4

The increasing demand of sophisticated devices for Medical Imaging, with submillimeter spatial resolution and high detection efficiency, motivates an in-depth study of detectors able to fulfill these requirements. In particular for Single Photon Emission Tomography applications, the on-going development of large LaBr3:Ce crystals makes very attractive their use as a system of gamma imaging. Single crystals can overcome the limitation in term of spatial resolution related to pixel size in scintillation arrays, once the problems of limited position linearity and image size are solved. In this work we use GEANT4 simulations in order to model different configurations based on LaBr3:Ce crystals coupled to a Hamamatsu H8500 Multi Anode Photomultiplier. The position linearity, the spatial and energy resolutions obtainable from optimum photodetection conditions are investigated. The values obtained by the Monte Carlo simulations are compared to the experimental results and found to be in good agreement with them upon tuning of some parameters

Ce doped lanthanum tri-bromide SPET scanner for molecular imaging RID F-8402-2011

The availability of LaBr(3):Ce crystals from St. Gobain has started various investigations in the field of medical imaging, in particular in PET, SPECT and Compton camera systems. At present LaBr(3):Ce crystals are available in a continuous shape covering up to 10 x 10 cm(2) with a thickness of 1 cm, in contrast, serious concerns are arising in pixellated manufacturing. With the aim of verifying the potentials introduced by LaBr(3):Ce for SPET imaging, two small gamma cameras based on Anger camera principle have been assembled and imaging performances were compared. Two crystals of LaBr(3):Ce and NaI(Tl) with the same detection area (5 x 5 cm(2)) and thickness of 5 and 1.5 mm, respectively were been integrally assembled with a H8500 Hamamatsu flat panel PMT. Through the thicker crystal, the LaBr(3):Ce camera showed superior imaging and detection performances at 140 keV compared with the NaI(Tl) one, with 0.9 mm FWHM intrinsic spatial resolution, 8% FWHM energy resolution and 80% intrinsic detection efficiency. (c) 2006 Elsevier B.V. All rights reserved