Double-Layered CZT Compton Imager

Young Hak Kim, Taewoong Lee, Wonho Lee

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


In this paper, we propose a double-layered cadmium zinc telluride Compton camera using the weighted list-mode maximum likelihood expectation maximization (MLEM) method. We performed a Monte Carlo simulation of the performance. The detection system comprised two detector arrays arranged in parallel. Each array consisted of 6 \times 6 crystals with a 7.5 mm pixel pitch. The dimension of a single crystal was 6 \times 6 \times 15 mm. For Compton imaging, the 137Cs activity was set to 78 kBq and the acquisition time was set to 2 hours. By applying the weighted MLEM method, the events with small angular uncertainty were more emphasized than those with large angular uncertainty. Each angular uncertainty was calculated based on the energy and geometry uncertainties of each event. We compared the traditional list-mode MLEM and the weighted list-mode MLEM for single and double detector arrays. The results showed that the combination of a double-layered imager with the weighted MLEM method represented the best image performance compared to other combinations. The sources at the offset positions were also simulated to estimate the directional dependency of the camera system.

Original languageEnglish
Article number7756299
Pages (from-to)1769-1773
Number of pages5
JournalIEEE Transactions on Nuclear Science
Issue number7
Publication statusPublished - 2017 Jul

Bibliographical note

Funding Information:
Manuscript received June 24, 2016; revised November 3, 2016; accepted November 22, 2016. Date of publication November 24, 2016; date of current version July 14, 2017. This work was supported by the Korea Foundation of Nuclear Safety (KoFONS) under Grant 1603015. Corresponding author: Wonho Lee. Y. Kim is with the Department of Bio-Convergence Engineering, Korea University, Seoul, Korea. T. Lee is with Health Science Research Center, Korea University, Seoul, Korea. W. Lee is with the School of Health and Environmental Science, Korea University, Seoul, Korea (e-mail: Color versions of one or more of the figures in this paper are available online at Digital Object Identifier 10.1109/TNS.2016.2632977

Publisher Copyright:
© 1963-2012 IEEE.


  • Cadmium zinc telluride
  • Compton camera
  • weighted list-mode maximum likelihood estimation

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


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