Abstract
For animal PET systems to achieve high sensitivity without adversely affecting spatial resolution, they must have the ability to measure depth-of-interaction (DOI). In this paper, we propose a novel four-layer PET system, and present the performances of modules built to verify the concept of the system. Each layer in the four-layer PET system has a relative offset of half a crystal pitch from other layers. Performances of the four-layer detector were estimated using a GATE Monte Carlo simulation code. The proposed system consists of six H9500 PMTs, each of which contains 3193 crystals. A sensitivity of 11.8% was obtained at the FOV center position of the proposed system. To verify the concept, we tested a PET module constructed using a H9500 flat panel PMT and LYSO crystals of cross-sectional area 1.5 × 1.5 mm2. The PET module was irradiated with a 1.8 MBq 22Na radiation source from the front or side of the crystals to obtain flood images of each crystal. Collimation for side irradiation was achieved using a pair of lead blocks of dimension 50 × 100 × 200 mm3. All crystals in the four layers were clearly identified in flood images, thus verifying the DOI capability of the proposed four-layer PET system. We also investigated the optimal combination of crystal lengths in the four-layer PET system using the GATE Monte Carlo simulation code to generate events from simulated radiation sources, and using the ML-EM algorithm to reconstruct simulated radiation sources. The combination of short crystal lengths near radiation sources and long crystal lengths near the PMT provides better spatial resolution than combinations of same crystal lengths in the four-layer PET system.
Original language | English |
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Article number | 5485133 |
Pages (from-to) | 976-981 |
Number of pages | 6 |
Journal | IEEE Transactions on Nuclear Science |
Volume | 57 |
Issue number | 3 PART 1 |
DOIs | |
Publication status | Published - 2010 Jun |
Bibliographical note
Funding Information:Manuscript received September 25, 2009; revised December 11, 2009; accepted February 22, 2010. Date of current version June 16, 2010. This work was supported by the Korea Science and Engineering Foundation, Republic of Korea, under Grants M20709005465-07B0900-46510, M20709005465-08B0900-46510, and R01-2006-000-10296-0. M. Ito is with the Department of Physics, Korea University, Seoul 126-701, Korea. J. S. Lee is with the Departments of Nuclear Medicine, Biomedical Sciences and WCU Brain and Cognitive Sciences, Institute of Radiation Medicine, Medical Research Center, and Interdisciplinary Programs in Radiation Applied Life Science Major, Seoul National University, Seoul 110-744, Korea. S. I. Kwon is with the Interdisciplinary Programs in Radiation Applied Life Science Major, Seoul National University College of Medicine, Seoul 110-744, Korea. G. S. Lee is with the Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 110-744, Korea. B. Hong, K. S. Lee, and K. S. Sim are with the Department of Physics, Korea University, Seoul 126-701, Korea. S. J. Lee is with the Department of Biomedical Engineering, Seonam University, Namwon 590-911, Korea. J. T. Rhee is with the Department of Physics, Konkuk University, Seoul 143-701, Korea. S. J. Hong is with the Department of Radiological Science, Eulji University, Seongnam 461-731, Korea (e-mail: [email protected]). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TNS.2010.2044892 Fig. 1. A proposed four-layer PET module which shows the relative offset of each layer relative to the bottom layer.
Keywords
- Depth of interaction (DOI))
- Four-layer animal PET
- GATE monte carlo simulation
- H9500 photomultiplier tube (PMT)
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering