@article{KleinesErkiZiemonsetal.1997, author = {Kleines, H. and Erki, I. and Ziemons, Karl and Zwoll, K.}, title = {ATM- und Multimedia Pilotsystem im Rahmen des Projektes M-FIBRe Aufbau und Erfahrungen}, series = {Bildverarbeitung f{\"u}r die Medizin : Algorithmen - Systeme - Anwendungen}, journal = {Bildverarbeitung f{\"u}r die Medizin : Algorithmen - Systeme - Anwendungen}, editor = {Lehmann, Thomas}, publisher = {Verl. der. Augustinus-Buchh.}, address = {Aachen}, isbn = {3-86073-519-5}, pages = {241 -- 248}, year = {1997}, language = {de} } @article{ErkiKleinesZiemonsetal.1997, author = {Erki, I. and Kleines, H. and Ziemons, Karl and Zwoll, K.}, title = {Interaktives System zur Darstellung funktionaler Bilddaten}, series = {Bildverarbeitung f{\"u}r die Medizin : Algorithmen - Systeme - Anwendungen}, journal = {Bildverarbeitung f{\"u}r die Medizin : Algorithmen - Systeme - Anwendungen}, editor = {Lehmann, Thomas}, publisher = {Verl. der. Augustinus-Buchh.}, address = {Aachen}, isbn = {3-86073-519-5}, pages = {249 -- 254}, year = {1997}, language = {de} } @article{GriessmeierSonnenbergWeckesseretal.1996, author = {Grießmeier, M. and Sonnenberg, F. and Weckesser, M. and Ziemons, Karl and Langen, K.-J. and M{\"u}ller-G{\"a}rtner, H. W.}, title = {Improvement of SPECT quantification in small brain structures by using experiment based recovery-coefficient corrections}, series = {European Journal of Nuclear Medicine}, volume = {23}, journal = {European Journal of Nuclear Medicine}, number = {9}, issn = {1619-7089}, pages = {1238 -- 1238}, year = {1996}, language = {en} } @article{KleinesZiemonsZwoll1998, author = {Kleines, H. and Ziemons, Karl and Zwoll, K.}, title = {Experiences with ATM in a multivendor pilot system at Forschungszentrum J{\"u}lich}, series = {IEEE Transactions on Nuclear Science}, volume = {45}, journal = {IEEE Transactions on Nuclear Science}, number = {4}, issn = {0018-9499}, pages = {1867 -- 1871}, year = {1998}, abstract = {The ATM technology for high speed serial transmission provides a new quality of communication by introducing novel features in a LAN environment, especially support of real time communication, of both LAN and WAN communication and of multimedia streams. In order to evaluate ATM for future DAQ systems and remote control systems as well as for a high speed picture archiving and communications system for medical images, Forschungszentrum Julich has build up a pilot system for the evaluation of ATM and standard low cost multimedia systems. It is a heterogeneous multivendor system containing a variety of switches and desktop solutions, employing different protocol options of ATM. The tests conducted in the pilot system revealed major difficulties regarding stability, interoperability and performance. The paper presents motivations, layout and results of the pilot system. Discussion of results concentrates on performance issues relevant for realistic applications, e.g., connection to a RAID system via NFS over ATM}, language = {en} } @article{TaylorSchmitzZiemonsetal.2000, author = {Taylor, J. G. and Schmitz, N. and Ziemons, Karl and Grosse-Ruyken, M.-L. and Gruber, O. and M{\"u}ller-G{\"a}rtner, H.-W. and Shah, N. J.}, title = {The network of brain areas involved in the motion aftereffect}, series = {Neuroimage}, volume = {11}, journal = {Neuroimage}, number = {4}, isbn = {1053-8119}, pages = {257 -- 270}, year = {2000}, abstract = {A network of brain areas is expected to be involved in supporting the motion aftereffect. The most active components of this network were determined by means of an fMRI study of nine subjects exposed to a visual stimulus of moving bars producing the effect. Across the subjects, common areas were identified during various stages of the effect, as well as networks of areas specific to a single stage. In addition to the well-known motion-sensitive area MT the prefrontal brain areas BA44 and 47 and the cingulate gyrus, as well as posterior sites such as BA37 and BA40, were important components during the period of the motion aftereffect experience. They appear to be involved in control circuitry for selecting which of a number of processing styles is appropriate. The experimental fMRI results of the activation levels and their time courses for the various areas are explored. Correlation analysis shows that there are effectively two separate and weakly coupled networks involved in the total process. Implications of the results for awareness of the effect itself are briefly considered in the final discussion.}, language = {en} } @article{FinkMarshallShahetal.2000, author = {Fink, G. R. and Marshall, J. C. and Shah, N. J. and Weiss, P.H. and Halligan, P. W. and Grosse-Ruyken, M. and Ziemons, Karl and Zilles, K. and Freund, H. J.}, title = {Line bisection judgments implicate right parietal cortex and cerebellum as assessed by fMRI}, series = {Neurology}, volume = {54}, journal = {Neurology}, number = {6}, isbn = {1526-632X}, pages = {1324 -- 1331}, year = {2000}, language = {en} } @article{BussmannEngelsFussetal.2000, author = {Bussmann, N. and Engels, R. and Fuss, L. and Kemmerling, G. and Reinartz, R. and Langen, K.-J. and Schelten, J. and Ziemons, Karl}, title = {Performance measurement of a new high resolution detector system for I-131 thyroid studies}, series = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, issn = {1082-3654}, pages = {22/35 -- 22/37}, year = {2000}, abstract = {A 2-dimensional detector system for high resolution thyroid I-131 scintigraphy was developed. It has a sensitive area of 4 cm×4 cm and consists of a lead-collimator and an array of 10×10 EGO crystals combined with a position sensitive photomultiplier. The spatial resolution and the sensitivity of the detector has been measured and compared to two commercially available gamma-cameras. Furthermore first patient measurements have been carried out}, language = {de} } @article{StreunBrandenburgLarueetal.2000, author = {Streun, M. and Brandenburg, G. and Larue, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.}, title = {Pulse recording by free-running sampling}, series = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2}, journal = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2}, issn = {1082-3654}, pages = {9/179 -- 9/181}, year = {2000}, abstract = {Pulses from a position-sensitive photomultiplier (PS-PMT) are recorded by free running ADCs at a sampling rate of 40 MHz. A four-channel acquisition-board has been developed which is equipped with four 12 bit-ADCs connected to one FPGA (field programmable gate array). The FPGA manages data acquisition and the transfer to the host computer. It can also work as a digital trigger, so a separate hardware-trigger can be omitted. The method of free running sampling provides a maximum of information, besides the pulse charge and amplitude also pulse shape and starting time are contained in the sampled data. These informations are crucial for many tasks such as distinguishing between different scintillator materials, determination of radiation type, pile-up recovery, coincidence detection or time-of-flight applications. The absence of an analog integrator allows coping with very high count rates. Since this method is going to be employed in positron emission tomography (PET), the position of an event is another important information. The simultaneous readout of four channels allows localization by means of center-of-gravity weighting. First results from a test setup with LSO-scintillators coupled to the PS-PMT are presented}, language = {en} } @article{HautzelTaylorKrauseetal.2001, author = {Hautzel, H. and Taylor, J. G. and Krause, B. J. and Schmitz, N. and Tellmann, L. and Ziemons, Karl and Shah, N. J. and Herzog, H. and M{\"u}ller-G{\"a}rtner, H.-W.}, title = {The motion aftereffect: more than area V5/MT? Evidence from 15O-butanol PET studies}, series = {Brain Research}, volume = {892}, journal = {Brain Research}, number = {2}, isbn = {0006-8993}, pages = {281 -- 292}, year = {2001}, abstract = {The motion aftereffect is a perceptual phenomenon which has been extensively investigated both psychologically and physiologically. Neuroimaging techniques have recently demonstrated that area V5/MT is activated during the perception of this illusion. The aim of this study was to test the hypothesis if a more broadly distributed network of brain regions subserves the motion aftereffect. To identify the neuronal structures involved in the perception of the motion aftereffect, regional cerebral blood flow (rCBF) measurements with positron emission tomography were performed in six normal volunteers. Data were analysed using SPM96. The motion-sensitive visual areas including area V5/MT were activated in both hemispheres. Additionally, the lateral parietal cortex bilaterally, the right dorsolateral prefrontal cortex, the anterior cingulate cortex and the left cerebellum showed significant increases in rCBF values during the experience of the waterfall illusion. In a further reference condition with identical attentional demand but no perception of a motion aftereffect elevated rCBF were found in these regions as well. In conclusion, our findings support the notion that the perceptual illusion of motion arises exclusively in the motion-sensitive visual area V5/MT. In addition, a more widespread network of brain regions including the prefrontal and parietal cortex is activated during the waterfall illusion which represents a non-motion aftereffect-specific subset of brain areas but is involved in more basic attentional processing and cognition.}, language = {de} } @article{StreunBrandenburgLarueetal.2001, author = {Streun, M. and Brandenburg, G. and Larue, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.}, title = {Pulse recording by free-running sampling}, series = {IEEE Transactions on Nuclear Science}, volume = {48}, journal = {IEEE Transactions on Nuclear Science}, number = {3}, isbn = {0018-9499}, pages = {524 -- 526}, year = {2001}, abstract = {Pulses from a position-sensitive photomultiplier (PS-PMT) are recorded by free-running ADCs at a sampling rate of 40 MHz. A four-channel acquisition board has been developed which is equipped with four 12-bit ADCs connected to one field programmable gate array (FPGA). The FPGA manages data acquisition and the transfer to the host computer. It can also work as a digital trigger, so a separate hardware trigger can be omitted. The method of free-running sampling provides a maximum of information, besides the pulse charge and amplitude also pulse shape and starting time are contained in the sampled data. This information is crucial for many tasks such as distinguishing between different scintillator materials, determination of radiation type, pile-up recovery, coincidence detection or time-of-flight applications. The absence of an analog integrator allows very high count rates to be dealt with. Since this method is to be employed in positron emission tomography (PET), the position of an event is also important. The simultaneous readout of four channels allows localization by means of center-of-gravity weighting. First results from a test setup with LSO scintillators coupled to the PS-PMT are presented here}, language = {en} }