Energy and Timing Response of Six Prototype Scintillators for TOF-PET

• Published in: IEEE transactions on nuclear science Vol. 55; no. 3; pp. 1404 - 1408
• Main Authors: Kyba, C.C.M., Glodo, J., van Loef, E.V.D., Karp, J.S., Shah, K.S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Crystals; Energy (nuclear); Energy resolution; Halides; Image reconstruction; Light scattering; LuI _3; Particle scattering; Photonic crystals; Photons; Positron emission tomography; Positrons; Prototypes; Scanners; scintillation; Spatial resolution; Time measurements; time-of-flight; Timing; Whole-body PET
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2008.921939

The recent development of fast scintillating crystals with high light output (such as LaBr 3 , LYSO, and LSO) has made it possible to incorporate time-of-flight information into whole-body positron emission tomography scanners (TOF-PET). The development of fast scintillators has continued, and scintillators such as CeBr 3 and the six crystals we report on here are candidates for future TOF-PET scanners. We have performed preliminary tests on six prototype scintillating crystals composed of YI 3 (2% Ce), (Lu,Gd)I 3 (2% Ce), Lul 3 (10% Ce), Lul 3 (5% Ce), Lul 3 (2% Ce), and Ce(Br,Cl) 3 . The crystals were coupled to a PMT to observe 511 keV photons produced by positron captures in a 22 Na point source. A LaBr 3 coincidence detector was used in order to make timing resolution measurements. The prototype samples had a range of timing resolutions from 160 ps to 250 ps (FWHM). Ce(Br,Cl) 3 was found to have the best timing resolution, with 160 ps, followed by Lul 3 (2% Ce) with 180 ps. These results are competitive with the 160 ps we observed for a pair of LaBr 3 crystals in coincidence with each other. The 2% Ce doped Lul 3 sample was found to have the best overall energy response, with an energy resolution (FWHM) of 6% at 511 keV. Energy resolution and light yield measurements are presented for each of the crystals.