Freek J Beekman

Summary

Affiliation: University Medical Center Utrecht
Country: The Netherlands

Publications

  1. ncbi Efficient fully 3-D iterative SPECT reconstruction with Monte Carlo-based scatter compensation
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room E02 222, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
    IEEE Trans Med Imaging 21:867-77. 2002
  2. ncbi Ordered subset reconstruction for x-ray CT
    F J Beekma
    Image Sciences Institute, University Hospital Utrecht, The Netherlands
    Phys Med Biol 46:1835-44. 2001
  3. ncbi Towards in vivo nuclear microscopy: iodine-125 imaging in mice using micro-pinholes
    Freek J Beekman
    Image Sciences Institute, University Hospital Utrecht, Heidelberglaan, The Netherlands
    Eur J Nucl Med Mol Imaging 29:933-8. 2002
  4. ncbi U-SPECT-I: a novel system for submillimeter-resolution tomography with radiolabeled molecules in mice
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
    J Nucl Med 46:1194-200. 2005
  5. ncbi Design and simulation of a high-resolution stationary SPECT system for small animals
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room STR 5 203, Universiteitsweg 100, 3584 CG, The Netherlands
    Phys Med Biol 49:4579-92. 2004
  6. ncbi Evaluation of 3D Monte Carlo-based scatter correction for 201Tl cardiac perfusion SPECT
    Jianbin Xiao
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Centre Utrecht, Utrecht, The Netherlands
    J Nucl Med 48:637-44. 2007
  7. ncbi Statistical reconstruction for x-ray CT systems with non-continuous detectors
    Wojciech Zbijewski
    Image Sciences Institute, Department of Nuclear Medicine and Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Stratenum, Universiteitsweg 100, STR5 203 3584 CG Utrecht, The Netherlands, and University Hospital, Brussels, Belgium
    Phys Med Biol 52:403-18. 2007
  8. ncbi Evaluation of 3D Monte Carlo-based scatter correction for 99mTc cardiac perfusion SPECT
    Jianbin Xiao
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Universiteitsweg 100, Utrecht, The Netherlands
    J Nucl Med 47:1662-9. 2006
  9. ncbi Monte Carlo-based down-scatter correction of SPECT attenuation maps
    Tomislav Bokulić
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Centre Utrecht, Universiteitsweg 100, STR 5 203, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 31:1173-81. 2004
  10. doi Multi-scale algorithm for improved scintillation detection in a CCD-based gamma camera
    Marc A N Korevaar
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CG, Utrecht, The Netherlands
    Phys Med Biol 54:831-42. 2009

Collaborators

Detail Information

Publications33

  1. ncbi Efficient fully 3-D iterative SPECT reconstruction with Monte Carlo-based scatter compensation
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room E02 222, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
    IEEE Trans Med Imaging 21:867-77. 2002
    ....
  2. ncbi Ordered subset reconstruction for x-ray CT
    F J Beekma
    Image Sciences Institute, University Hospital Utrecht, The Netherlands
    Phys Med Biol 46:1835-44. 2001
    ..Even by applying such a relatively slow final iteration, OSC produces almost an equal resolution and lesion contrast as the standard convex algorithm, but more than two orders of magnitude faster...
  3. ncbi Towards in vivo nuclear microscopy: iodine-125 imaging in mice using micro-pinholes
    Freek J Beekman
    Image Sciences Institute, University Hospital Utrecht, Heidelberglaan, The Netherlands
    Eur J Nucl Med Mol Imaging 29:933-8. 2002
    ..Possible future applications and extension to ultra-high-resolution emission tomography are discussed...
  4. ncbi U-SPECT-I: a novel system for submillimeter-resolution tomography with radiolabeled molecules in mice
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
    J Nucl Med 46:1194-200. 2005
    ..Here, we present a SPECT system (U-SPECT-I) dedicated to radionuclide imaging of murine organs at a submillimeter resolution...
  5. ncbi Design and simulation of a high-resolution stationary SPECT system for small animals
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room STR 5 203, Universiteitsweg 100, 3584 CG, The Netherlands
    Phys Med Biol 49:4579-92. 2004
    ..Simulation results indicate that future pinhole SPECT systems are likely to bring about significant improvements in radio-molecular imaging of small animals...
  6. ncbi Evaluation of 3D Monte Carlo-based scatter correction for 201Tl cardiac perfusion SPECT
    Jianbin Xiao
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Centre Utrecht, Utrecht, The Netherlands
    J Nucl Med 48:637-44. 2007
    ..Monte Carlo simulation is a general and accurate method well suited to modeling this scatter...
  7. ncbi Statistical reconstruction for x-ray CT systems with non-continuous detectors
    Wojciech Zbijewski
    Image Sciences Institute, Department of Nuclear Medicine and Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Stratenum, Universiteitsweg 100, STR5 203 3584 CG Utrecht, The Netherlands, and University Hospital, Brussels, Belgium
    Phys Med Biol 52:403-18. 2007
    ..When applied to randomly located faulty detector elements, SR produces images free of substantial ring artefacts even for cases where defective pixels cover as much as 3% of the detector area...
  8. ncbi Evaluation of 3D Monte Carlo-based scatter correction for 99mTc cardiac perfusion SPECT
    Jianbin Xiao
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Universiteitsweg 100, Utrecht, The Netherlands
    J Nucl Med 47:1662-9. 2006
    ..Both of these scatter correction methods were used in conjunction with attenuation correction and resolution recovery...
  9. ncbi Monte Carlo-based down-scatter correction of SPECT attenuation maps
    Tomislav Bokulić
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Centre Utrecht, Universiteitsweg 100, STR 5 203, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 31:1173-81. 2004
    ..Monte Carlo down-scatter simulation in concert with statistical reconstruction provides accurate down-scatter correction of attenuation maps...
  10. doi Multi-scale algorithm for improved scintillation detection in a CCD-based gamma camera
    Marc A N Korevaar
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CG, Utrecht, The Netherlands
    Phys Med Biol 54:831-42. 2009
    ..0 10(3) to 448 microm FWHM. We conclude that the multi-scale algorithm significantly improves CCD-based gamma cameras as can be applied in future SPECT systems...
  11. doi A micro-machined retro-reflector for improving light yield in ultra-high-resolution gamma cameras
    Jan W T Heemskerk
    Image Sciences Institute, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands
    Phys Med Biol 54:3003-14. 2009
    ..The full width at tenth maximum (FWTM) improvement was 13%. Therefore, this enhancement is a next step towards realizing compact high-resolution devices for imaging gamma emitters...
  12. ncbi Efficient Monte Carlo based scatter artifact reduction in cone-beam micro-CT
    Wojciech Zbijewski
    Department of Nuclear Medicine, Image Sciences Institute, Rudolf Magnus Institute of Neuroscience, STR5 203 3584 CG Utrecht, The Netherlands
    IEEE Trans Med Imaging 25:817-27. 2006
    ..In conclusion, a general, accurate, and efficient scatter correction algorithm is developed that requires no mechanical modifications of the scanning equipment and results in only a moderate increase in the total reconstruction time...
  13. pmc Small field-of-view dedicated cardiac SPECT systems: impact of projection truncation
    Jianbin Xiao
    Image Sciences Institute, University Medical Centre Utrecht, Universiteitsweg 100, STR 5 203, 3584 CG, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 37:528-36. 2010
    ..In addition, we evaluated a simple correction method to mitigate the effects of truncation...
  14. ncbi Front-illuminated versus back-illuminated photon-counting CCD-based gamma camera: important consequences for spatial resolution and energy resolution
    Jan W T Heemskerk
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room STR 5 203, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
    Phys Med Biol 52:N149-62. 2007
    ..We conclude that the use of BI EMCCDs may significantly improve the imaging capabilities and the cost efficiency of CCD-based high-resolution gamma cameras...
  15. ncbi Photon penetration and scatter in micro-pinhole imaging: a Monte Carlo investigation
    Frans van der Have
    Image Sciences Institute, UMC Utrecht STR 5 203, Universiteitsweg 100 3584 CG Utrecht, The Netherlands
    Phys Med Biol 49:1369-86. 2004
    ..For all materials studied, the total amounts of penetrated and scattered photons changed approximately linearly with respect to the pinhole diameter...
  16. doi System calibration and statistical image reconstruction for ultra-high resolution stationary pinhole SPECT
    Frans van der Have
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
    IEEE Trans Med Imaging 27:960-71. 2008
    ..6-mm pinholes and below 0.35 mm with 0.3-mm pinholes. In addition, we show that different approximations, such as truncating the PSF kernel, with significant reduction of reconstruction time, can still lead to acceptable reconstructions...
  17. doi Degradation of myocardial perfusion SPECT images caused by contaminants in thallous (201Tl) chloride
    Steven G Staelens
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 35:922-32. 2008
    ..Therefore, we investigate the effects of the contaminants in terms of detected fractions of photons in projections and contrast degradation in reconstructed images...
  18. doi U-SPECT-II: An Ultra-High-Resolution Device for Molecular Small-Animal Imaging
    Frans van der Have
    Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
    J Nucl Med 50:599-605. 2009
    ..We present a new rodent SPECT system (U-SPECT-II) that enables molecular imaging of murine organs down to resolutions of less than half a millimeter and high-resolution total-body imaging...
  19. ncbi A pinhole gamma camera with optical depth-of-interaction elimination
    Marc A N Korevaar
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands Section of Radiation Detection and Medical Imaging, Applied Sciences, Delft University of Technology, Delft, The Netherlands
    Phys Med Biol 54:N267-72. 2009
    ..Therefore, the detector has great potential for increasing the resolution of pinhole SPECT...
  20. ncbi Hybrid scatter correction applied to quantitative holmium-166 SPECT
    Tim C de Wit
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Centre Utrecht, Universiteitsweg 100, STR 5 203, Utrecht, The Netherlands
    Phys Med Biol 51:4773-87. 2006
    ..It is expected that the method, with adapted window settings, also can be applied to other isotopes with high energy peaks that contaminate the photopeak data, such as I-131 or In-111...
  21. pmc Intratumoral administration of holmium-166 acetylacetonate microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer
    Wouter Bult
    Imaging Division, Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
    PLoS ONE 8:e52178. 2013
    ..This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI...
  22. doi Pixel-based subsets for rapid multi-pinhole SPECT reconstruction
    Woutjan Branderhorst
    Image Sciences Institute, University Medical Center Utrecht, The Netherlands
    Phys Med Biol 55:2023-34. 2010
    ..We found that POSEM can be operated at acceleration factors that are often an order of magnitude higher than in traditional OSEM...
  23. ncbi Characterization and suppression of edge and aliasing artefacts in iterative x-ray CT reconstruction
    Wojciech Zbijewski
    Image Sciences Institute, UMC Utrecht, Stratenum, Universiteitsweg 100, STR5 203 3584 CG Utrecht, The Netherlands
    Phys Med Biol 49:145-57. 2004
    ..Resulting SR images have superior noise-resolution trade-off compared to FBP, which may facilitate dose reduction during CT examinations...
  24. doi Intra-patient reproducibility of myocardial SPECT imaging with 201Tl
    Barbra E Backus
    Department of Nuclear Medicine, St Antonius Hospital, Koekoekslaan 1, Postbus 2500, 3430 EM, Nieuwegein, The Netherlands
    J Nucl Cardiol 16:97-104. 2009
    ....
  25. ncbi Factors affecting the sensitivity and detection limits of MRI, CT, and SPECT for multimodal diagnostic and therapeutic agents
    Peter R Seevinck
    Image Sciences Institute, Dept of Radiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands
    Anticancer Agents Med Chem 7:317-34. 2007
    ..In this, emphasis was put on the factors that must be taken into account when extrapolating the findings for HoMS to other diagnostic tasks, other contrast agents, other experimental conditions, and other scan protocols...
  26. ncbi Comparison of methods for suppressing edge and aliasing artefacts in iterative x-ray CT reconstruction
    Wojciech Zbijewski
    Image Sciences Institute, Department of Nuclear Medicine and Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Stratenum, Universiteitsweg 100, STR5 203 3584 CG Utrecht, The Netherlands
    Phys Med Biol 51:1877-89. 2006
    ..We show that the use of a fine grid results in a more adequate suppression of artefacts than the smoothing of projections or using the Kaiser-Bessel image representation...
  27. ncbi Suppression of intensity transition artifacts in statistical x-ray computer tomography reconstruction through radon inversion initialization
    Wojciech Zbijewski
    Rudolf Magnus Institute of Neuroscience and Image Sciences Institute, University Medical Center Utrecht, Universiteitsweg 100, STR5 203, 3584 CG Utrecht, The Netherlands
    Med Phys 31:62-9. 2004
    ....
  28. ncbi Three-dimensional histologic validation of high-resolution SPECT of antibody distributions within xenografts
    Woutjan Branderhorst
    Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
    J Nucl Med 55:830-7. 2014
    ....
  29. ncbi Efficient simulation of SPECT down-scatter including photon interactions with crystal and lead
    Hugo W A M de Jong
    Image Sciences Institute, University Medical Center, Utrecht, The Netherlands
    Med Phys 29:550-60. 2002
    ..We conclude that accurate and efficient simulation of down-scatter is now possible including the major effects of the nonuniform mass density of the patient as well as photon interactions with the crystal and collimator lead...
  30. ncbi Monte Carlo simulations of pinhole imaging accelerated by kernel-based forced detection
    Mark Gieles
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center, Utrecht, The Netherlands
    Phys Med Biol 47:1853-67. 2002
    ..A simulator accelerated by KFD could serve as a practical tool to improve iterative image reconstruction...
  31. ncbi Comparison of methods for thyroid volume estimation in patients with Graves' disease
    Johannes W van Isselt
    Department of Nuclear Medicine 02 222, Imaging Sciences Institute, University Medical Center Utrecht, P O Box 85500, 3508 GA, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 30:525-31. 2003
    ..8+/-7.5 ml) was not negligible. In conclusion, SPET is preferred over PS for accurate measurements of thyroid volume. US is the most accurate of the three modalities, if a correction is made for bias...
  32. pmc Targeted multi-pinhole SPECT
    Woutjan Branderhorst
    Image Sciences Institute, University Medical Centre Utrecht, Utrecht, The Netherlands
    Eur J Nucl Med Mol Imaging 38:552-61. 2011
    ..Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of improved targeting of the pinhole focus...
  33. ncbi Photon-counting versus an integrating CCD-based gamma camera: important consequences for spatial resolution
    Freek J Beekman
    Department of Nuclear Medicine, Image Sciences Institute, University Medical Center Utrecht, Room STR 5 203, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
    Phys Med Biol 50:N109-19. 2005
    ..Energy resolution was estimated to be approximately 35 keV FWHM for a 1:1 taper. We conclude that CCD-based gamma cameras have great potential for applications such as in vivo imaging of gamma emitters...