期刊
IEEE TRANSACTIONS ON NUCLEAR SCIENCE
卷 62, 期 1, 页码 36-41出版社
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/TNS.2015.2388757
关键词
Avalanche photodiodes; energy resolution; LabPET; LGSO; positron emission tomography; scintillators; small-animal PET scanner; timing resolution
资金
- Natural Science and Engineering Research Council of Canada (NSERC)
- Canadian Institutes of Health Research (CIHR)
- Fonds de recherche du Quebec - Nature et technologies (FRQNT)
- FRSQ
The scintillator is one of the key building blocks that critically determine the physical performance of PET detectors. The quest for scintillation crystals with improved characteristics has been crucial in designing scanners with superior imaging performance. Recently, it was shown that the decay time constant of high lutetium content (LGSO) scintillators can be adjusted by varying the cerium concentration from 0.025 mol% to 0.75 mol%, thus providing interesting characteristics for phoswich detectors. The high light output (90%-120% NaI) and the improved spectral match of these scintillators with avalanche photodiode (APD) readout promise superior energy and timing resolutions. Moreover, their improved mechanical properties, as compared to conventional LGSO (Lu1.8Gd0.2SiO5:Ce), make block array manufacturing readily feasible. To verify these assumptions, new phoswich block arrays made of LGSO-90% Lu with low and high mol% Ce concentrations were fabricated and assembled into modules dedicated to the LabPET scanner. Typical crystal decay time constants were 31 ns and 47 ns, respectively. Phoswich crystal identification performed using a digital pulse shape discrimination algorithm yielded an average 8% error. At 511 keV, an energy resolution of 17-21% was obtained, while coincidence timing resolution between 4.6 ns and 5.2 ns was achieved. The characteristics of this new LGSO-based phoswich detector module are expected to improve the LabPET scanner performance. The higher stopping power would increase the detection efficiency. The better timing resolution would also allow the use of a narrower coincidence window, thus minimizing the random event rate. Altogether, these two improvements will significantly enhance the noise equivalent count rate performance of an all LGSO-based LabPET scanner.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据