TY  - JOUR
A1  - Khodaverdi, M.
A1  - Chatziioannou, A. F.
A1  - Weber, S.
A1  - Ziemons, Karl
A1  - Halling, H.
A1  - Pietrzyk, U.
T1  - Investigation of different MicroCT scanner configurations by GEANT4 simulations
JF  - IEEE Transactions on Nuclear Science
N2  - 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.
Y1  - 2005
SN  - 0018-9499
VL  - 52
IS  - 1
SP  - 188
EP  - 192
ER  - 
TY  - JOUR
A1  - Khodaverdi, M.
A1  - Chaziioannou, A. F.
A1  - Weber, S.
A1  - Ziemons, Karl
A1  - Halling, H.
A1  - Pietrzyk, U.
T1  - Investigation of different microCT scanner configurations by GEANT4 simulations
JF  - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4
N2  - 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.
Y1  - 2004
SN  - 1082-3654
SP  - 2989
EP  - 2993
ER  - 
TY  - JOUR
A1  - Christ, D.
A1  - Hollendung, A.
A1  - Larue, H.
A1  - Parl, C.
A1  - Streun, M.
A1  - Weber, S.
A1  - Ziemons, Karl
A1  - Halling, H.
T1  - Homogenization of the MultiChannel PM gain by inserting light attenuating masks
JF  - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4
N2  - 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.
Y1  - 2004
SN  - 1082-3654
SP  - 2382
EP  - 2385
ER  - 
TY  - CHAP
A1  - Terstegge, Andreas
A1  - Weber, S.
A1  - Herzog, H.
A1  - Müller-Gärtner, H. W.
A1  - Halling, H.
T1  - Design and implementation aspects of a 3D reconstruction algorithm for the Jülich TierPET system
T2  - 1997 International Meeting on Fully ThreeDimensional Image Reconstruction in Radiology and Nuclear Medicine : 3D97
Y1  - 1997
SP  - 170
EP  - 173
ER  - 
TY  - CHAP
A1  - Weber, S.
A1  - Terstegge, Andreas
A1  - Engels, R.
A1  - Herzog, H.
A1  - Reinartz, R.
A1  - Reinhart, P.
A1  - Rongen, F.
A1  - Müller-Gärtner, H. W.
A1  - Halling, H.
T1  - The KFA TierPET: performance characteristics and measurements
T2  - Conference record / 1996 IEEE Nuclear Science Symposium [and Medical Imaging], November 2 - 9, 1996, Anaheim, California ; vol. 2
Y1  - 1996
SN  - 0-7803-3534-1
SN  - 1082-3654
SP  - 1117
EP  - 1119
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - CHAP
A1  - Weber, S.
A1  - Terstegge, Andreas
A1  - Halling, H.
A1  - Herzog, H.
A1  - Reinartz, R.
A1  - Reinhart, P.
A1  - Rongen, F.
A1  - Müller-Gärtner, H.-W.
T1  - The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity
T2  - Conference record / 1995 IEEE Nuclear Science Symposium and Medical Imaging, October 21 - 28, 1995, San Francisco ; vol. 2
Y1  - 1995
SN  - 078033180X ; 0780331818 ; 0780331826
SP  - 1002
EP  - 1005
PB  - IEEE
CY  - Piscataway, NJ
ER  -