@article{KhodaverdiChatziioannouWeberetal.2005,
  author    = {Khodaverdi, M. and Chatziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.},
  title     = {Investigation of different MicroCT scanner configurations by GEANT4 simulations},
  series = {IEEE Transactions on Nuclear Science},
  volume    = {52},
  journal   = {IEEE Transactions on Nuclear Science},
  number    = {1},
  isbn      = {0018-9499},
  pages     = {188 -- 192},
  year      = {2005},
  abstract  = {This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.},
  language  = {en}
}
@article{KhodaverdiChaziioannouWeberetal.2004,
  author    = {Khodaverdi, M. and Chaziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.},
  title     = {Investigation of different microCT scanner configurations by GEANT4 simulations},
  series = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  journal   = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  issn      = {1082-3654},
  pages     = {2989 -- 2993},
  year      = {2004},
  abstract  = {This study has been performed to design the combination of the new ClearPET TM (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal Positron Emission Tomography (PET) system, with a microComputed Tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.},
  language  = {en}
}
@article{ChristHollendungLarueetal.2004,
  author    = {Christ, D. and Hollendung, A. and Larue, H. and Parl, C. and Streun, M. and Weber, S. and Ziemons, Karl and Halling, H.},
  title     = {Homogenization of the MultiChannel PM gain by inserting light attenuating masks},
  series = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  journal   = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  issn      = {1082-3654},
  pages     = {2382 -- 2385},
  year      = {2004},
  abstract  = {MultiChannel Photomultipliers (PM), like the R7600-00-M64 or R5900-00-M64 from Hamamatsu, are often chosen as photodetectors in high-resolution positron emission tomography (PET). A major problem of this PM is the nonuniform channel gain. In order to solve this problem, light attenuating masks were created. The aim of the masks is a homogenization of the output of all 64 channels using different hole sizes at the channel positions. The hole area, which is individually defined for the different channels, is inversely proportional to the channel gain. The measurements by inserting light attenuating masks improved a homogenization to a ratio of 1:1.2.},
  language  = {en}
}
@inproceedings{TersteggeWeberHerzogetal.1997,
  author    = {Terstegge, Andreas and Weber, S. and Herzog, H. and M{\"u}ller-G{\"a}rtner, H. W. and Halling, H.},
  title     = {Design and implementation aspects of a 3D reconstruction algorithm for the J{\"u}lich TierPET system},
  series = {1997 International Meeting on Fully ThreeDimensional Image Reconstruction in Radiology and Nuclear Medicine : 3D97},
  booktitle = {1997 International Meeting on Fully ThreeDimensional Image Reconstruction in Radiology and Nuclear Medicine : 3D97},
  pages     = {170 -- 173},
  year      = {1997},
  language  = {en}
}
@inproceedings{WeberTersteggeEngelsetal.1996,
  author    = {Weber, S. and Terstegge, Andreas and Engels, R. and Herzog, H. and Reinartz, R. and Reinhart, P. and Rongen, F. and M{\"u}ller-G{\"a}rtner, H. W. and Halling, H.},
  title     = {The KFA TierPET: performance characteristics and measurements},
  series = {Conference record / 1996 IEEE Nuclear Science Symposium [and Medical Imaging], November 2 - 9, 1996, Anaheim, California ; vol. 2},
  booktitle = {Conference record / 1996 IEEE Nuclear Science Symposium [and Medical Imaging], November 2 - 9, 1996, Anaheim, California ; vol. 2},
  publisher = {IEEE},
  address   = {Piscataway, NJ},
  organization    = {Institute of Electrical and Electronics Engineers},
  isbn      = {0-7803-3534-1},
  issn      = {1082-3654},
  pages     = {1117 -- 1119},
  year      = {1996},
  language  = {en}
}
@inproceedings{WeberTersteggeHallingetal.1995,
  author    = {Weber, S. and Terstegge, Andreas and Halling, H. and Herzog, H. and Reinartz, R. and Reinhart, P. and Rongen, F. and M{\"u}ller-G{\"a}rtner, H.-W.},
  title     = {The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity},
  series = {Conference record / 1995 IEEE Nuclear Science Symposium and Medical Imaging, October 21 - 28, 1995, San Francisco ; vol. 2},
  booktitle = {Conference record / 1995 IEEE Nuclear Science Symposium and Medical Imaging, October 21 - 28, 1995, San Francisco ; vol. 2},
  publisher = {IEEE},
  address   = {Piscataway, NJ},
  organization    = {Institute of Electrical and Electronics Engineers},
  isbn      = {078033180X ; 0780331818 ; 0780331826},
  pages     = {1002 -- 1005},
  year      = {1995},
  language  = {en}
}