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Title: Factors influencing timing resolution in a commercial LSO PETcamera

Abstract

The CPS Accel is a commercial PET camera based on a block detector with 64 LSO scintillator crystals (each 6.75 x 6.75 x 25 mm)read out with 4 photomultiplier tubes. The excellent timing resolution of LSO suggests that this camera might be used for time-of-flight (TOF) PET, thereby reducing the statistical noise significantly. Although the Accel achieves 3 ns coincidence resolution (a factor of two better than BGO-based PET cameras), its timing resolution is nearly an order of magnitude worse than that demonstrated with individual LSO crystals. This paper quantifies the effect on the timing of each component in the Accel timing chain to identify which components most limit the camera's timing resolution. The components in the timing chain are: the scintillator crystal, the photomultiplier tube (PMT), the constant fraction discriminator (CFD), and the time to digital converter (TDC). To measure the contribution of each component, we construct a single crystal test system with high-performance versions of these components. This system achieves 221 ps fwhm coincidence timing resolution, which is used as a baseline measurement. One of the high-performance components is replaced by a production component, the coincidence timing resolution is re-measured, and the difference between measurements is the contributionmore » of that (production) component. We find that the contributions of the TDC, CFD, PMT, and scintillator are 2000 ps, 1354 ps, 422 ps, and 326 psfwhm respectively, and that the overall timing resolution scales like the square root of the amount of scintillation light detected by the PMT. Based on these measurements we predict that the limit for the coincidence timing resolution in a practical, commercial, LSO-based PET camera is 528ps fwhm.« less

Authors:
;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Office of Biological andEnvironmental Research, Medical Sciences Division; National Institutes ofHealth Grant R33-EB001928
OSTI Identifier:
881727
Report Number(s):
LBNL-58238
Journal ID: ISSN 0018-9499; IETNAE; R&D Project: L0252; BnR: 400412000; TRN: US0602983
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science; Journal Volume: 53; Journal Issue: 1pt1; Related Information: Journal Publication Date: 02/2006
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 62 RADIOLOGY AND NUCLEAR MEDICINE; CAMERAS; DISCRIMINATORS; MONOCRYSTALS; PHOSPHORS; PHOTOMULTIPLIERS; PRODUCTION; RESOLUTION; SCINTILLATIONS; PET time-of-flight

Citation Formats

Moses, William W., and Ullisch, Marcus. Factors influencing timing resolution in a commercial LSO PETcamera. United States: N. p., 2004. Web.
Moses, William W., & Ullisch, Marcus. Factors influencing timing resolution in a commercial LSO PETcamera. United States.
Moses, William W., and Ullisch, Marcus. Sat . "Factors influencing timing resolution in a commercial LSO PETcamera". United States. doi:. https://www.osti.gov/servlets/purl/881727.
@article{osti_881727,
title = {Factors influencing timing resolution in a commercial LSO PETcamera},
author = {Moses, William W. and Ullisch, Marcus},
abstractNote = {The CPS Accel is a commercial PET camera based on a block detector with 64 LSO scintillator crystals (each 6.75 x 6.75 x 25 mm)read out with 4 photomultiplier tubes. The excellent timing resolution of LSO suggests that this camera might be used for time-of-flight (TOF) PET, thereby reducing the statistical noise significantly. Although the Accel achieves 3 ns coincidence resolution (a factor of two better than BGO-based PET cameras), its timing resolution is nearly an order of magnitude worse than that demonstrated with individual LSO crystals. This paper quantifies the effect on the timing of each component in the Accel timing chain to identify which components most limit the camera's timing resolution. The components in the timing chain are: the scintillator crystal, the photomultiplier tube (PMT), the constant fraction discriminator (CFD), and the time to digital converter (TDC). To measure the contribution of each component, we construct a single crystal test system with high-performance versions of these components. This system achieves 221 ps fwhm coincidence timing resolution, which is used as a baseline measurement. One of the high-performance components is replaced by a production component, the coincidence timing resolution is re-measured, and the difference between measurements is the contribution of that (production) component. We find that the contributions of the TDC, CFD, PMT, and scintillator are 2000 ps, 1354 ps, 422 ps, and 326 psfwhm respectively, and that the overall timing resolution scales like the square root of the amount of scintillation light detected by the PMT. Based on these measurements we predict that the limit for the coincidence timing resolution in a practical, commercial, LSO-based PET camera is 528ps fwhm.},
doi = {},
journal = {IEEE Transactions on Nuclear Science},
number = 1pt1,
volume = 53,
place = {United States},
year = {Sat Oct 23 00:00:00 EDT 2004},
month = {Sat Oct 23 00:00:00 EDT 2004}
}