Freek J. Beekman
Delft University of Technology
183 Papers
1.9K Citations
Freek J. Beekman is an academic researcher from Delft University of Technology. The author has contributed to research in topics: Iterative reconstruction & Imaging phantom. The author has an hindex of 49, co-authored 179 publications. Previous affiliations of Freek J. Beekman include University of California, Los Angeles & University Medical Center Utrecht.
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Papers
Depth-of-interaction detection and correction with a multi-scale algorithm in CCD based gamma cameras
Marc A N Korevaar,Jan W. T. Heemskerk,Marlies C. Goorden,Freek J. Beekman +3 more
- 01 Oct 2008
TL;DR: A fast analytic scintillation detection algorithm that makes use of a depth-dependent light spread model and as a result is able to determine the DOI in the scintillator is developed, which significantly improves CCD based gamma cameras as can be applied in future SPECT systems.
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Effects of reconstruction voxelization in iterative X-ray CT reconstruction
Wojciech Zbijewski,Freek J. Beekman +1 more
- 01 Dec 2003
TL;DR: In this paper, the edge artifacts are identified as interference patterns and as severe overshoots in the areas of sharp intensity transitions in X-ray CT data and a fundamental solution to the problem is to perform the reconstructions on an image grid that is finer than typically employed for FBP reconstruction.
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SiPM side detectors for performance enhancements of an EMCCD-based gamma camera
S. Salvador,Marc A N Korevaar,Jan W T Heemskerk,R. Kreuger,J. Huizenga,Stefan Seifert,Dennis R. Schaart,Freek J. Beekman +7 more
- 01 Oct 2011
TL;DR: In this paper, the results obtained using 12 SiPMs optically coupled to a 3 mm thick CsI:Tl crystal where the prelocated events are reconstructed using a maximum likelihood algorithm using Look-Up Tables (LUTs) evaluated by Monte-Carlo simulations to retrieve the interaction positions via the individual SiPM signals.
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•Journal Article
Ultra-high resolution cardiac SPECT of frozen animals as an alternative to autoradiography
TL;DR: In this paper, an anesthetized mouse was intravenously injected with 500MBq of Tc-99m-tetrafosmin and placed in a polymethylmethacrylate cylinder and was euthanized by placing it in liquid nitrogen.
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