We investigate the potentials of digitally sampling scintillation pulses techniques for positron emission tomography (PET) in this paper, focusing on the determination of the event time. We have built, and continue building, a digital library of PET event waveforms generated with various combinations of photo-detectors and scintillator materials, with various crystal sizes. Events in this digital library are obtained at a high sampling of 20 GSps (Giga-samples per second) so that their waveforms are recorded with high accuracy. To explore the potential advantages of digitally sampling scintillation pulses, we employ a dataset in the above-mentioned library to evaluate two methods for digitizing the event pulses and linear interpolation techniques to analyze the resulting digital samples. Our results show that the two digitization methods that we studied can yield a coincidence timing resolution of about 300 ps FWHM when applied to events generated by a pair of LSO + PMT detector units. This timing resolution is comparable with that is achieved by the same detector pair with a constant fraction discriminator (CFD). As a benchmark, regular-time sampling (RTS) method, usually implemented with very fast traditional analog-to-digital converters (ADCs) for digitizing scintillation pulses, is not feasible for a multi-channel system like a PET system. Digitizing scintillation pulses with multi-voltage threshold (MVT) method could be implemented at a reasonable cost for a PET system. With digitized PET event samples, various digital signal processing (DSP) techniques can be implemented to determine event arrival time. Our results have therefore demonstrated the promising potentials of digitally sampling scintillation pulses techniques in PET imaging.
|Number of pages||7|
|Journal||IEEE Transactions on Nuclear Science|
|State||Published - Oct 2009|
Bibliographical noteFunding Information:
Manuscript received August 01, 2008; revised December 15, 2008. Current version published October 07, 2009. This work was supported in part by a UChicago Argonne internal Grant LDRD #2006-075-NO, in part by the ACS-IRG Grant 6-9512, in part by the NIH Grants R01 EB000225, R33 EB001928, and R01 EB006085, in part by the NSF Grant PHY04–5668, in part by the DOE Grant DE FG02-06 ER 41426, in part by the NSF (China) Grant 60602028, in part by the Ministry of Science and Technology (China) Grant 2009 DFR30580, and in part by the Ministry of Education (China) Grant 107073. The Argonne and Lawrence Berkeley National Laboratories were supported by the Office of Science of the Department of Energy under Contract DE-AC02-06CH11357 and DE-AC02-05CH11231.
- Digital signal processing (DSP)
- Positron emission tomography (PET)
- Scintillation pulse
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering