title: Monolithic LaBr₃:Ce crystals on silicon photomultiplier arrays for time-of-flight positron emission tomography.
abstract: Positron emission tomography detectors based on monolithic scintillation crystals exhibit good spatial and energy resolution, intrinsically provide depth-of-interaction information, have high γ-photon capture efficiency, and may reduce the manufacturing costs compared to pixelated crystal arrays. Here, we present the characterization of a detector consisting of a 18.0 mm×16.2 mm×10.0 mm monolithic LaBr₃:5%Ce scintillator directly coupled to a 4×4 array of silicon photomultipliers. An energy resolution of 6.4% full-width-at-half-maximum (FWHM) was obtained. The point-spread-function (PSF) was determined for different regions of the detector. The full-width-at-half-maximum (FWHM) of the PSF was measured to be <1.5 mm at the center of the detector and <1.7 mm averaged over the entire crystal. Both values are not corrected for the ~0.6 mm FWHM test beam diameter. Furthermore, the influence of edge effects was investigated. We found that near the edges of the detector the spatial resolution degrades to 2.2 mm (FWHM), and a bias in the position estimates, up to 1.5 mm, was observed. Moreover, the coincidence resolving time for two identical detectors in coincidence was measured to be as small as ~198 ps FWHM.
authors.affiliation: Delft University of Technology, Radiation Detection & Medical Imaging, Mekelweg 15, 2629 JB Delft, The Netherlands. s.seifert@tudelft.nl
authors.forename: Stefan
authors.initials: S
authors.lastname: Seifert
authors.forename: Herman T
authors.initials: HT
authors.lastname: van Dam
authors.forename: Jan
authors.initials: J
authors.lastname: Huizenga
authors.forename: Ruud
authors.initials: R
authors.lastname: Vinke
authors.forename: Peter
authors.initials: P
authors.lastname: Dendooven
authors.forename: Herbert
authors.initials: H
authors.lastname: Löhner
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Schaart
mesh_terms: D001965:Bromides / Q000737:chemistry*; D002563:Cerium / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D012588:Scintillation Counting / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry*
chemical_list: D001965:Bromides; C547466:lanthanum bromide; D002563:Cerium; D007811:Lanthanum; D012825:Silicon