TY - CHAP A1 - Müller-Veggian, Mattea A1 - Kops, Elena Rota A1 - Quin, Peng A1 - Herzog, Hans T1 - MRI Based Attenuation Correction for Brain PET Images T2 - Advances in medical engineering / [3rd RPT - Remagener Physiktage together with the Second Scientific Workshop of Medical Robotics, Navigation and Visualization ... Remagen ... 7.-9. März 2007]. Thorsten M. Buzug (ed.) Part 1. N2 - This work describes a procedure to yield attenuation maps from MR images which are used for the absorption correction (AC) of brain PET data. Such an approach could be mandatory for future combined PET and MRI scanners, which probably do not include a transmission facility. T1-weighted MR images were segmented into brain tissue, bone, soft tissue, and sinus; attenuation coefficients corresponding to elemental composition and density as well as to 511 keV photon energy were respectively assigned. Attenuation maps containing up to four compartments were created and forward projected into sinograms with attenuation factors which then were used for AC during reconstruction of FDG-PET data. The commonly used AC based on a radioactive (68Ge) transmission scan served as reference. The reconstructed radioactivity values obtained with the MRI-based AC were about 20% lower than those obtained with PET-based AC if the skull was not taken into account. Considering the skull the difference was still about 10%. Our investigations demonstrate the feasibility of a MRI-based AC, but revealed also the necessity of a satisfying delineation of bone thickness which tends to be underestimated in our first approach of T1-weighted MR image segmentation. Y1 - 2007 SN - 978-3-540-68763-4 U6 - http://dx.doi.org/10.1007/978-3-540-68764-1_15 N1 - Springer proceedings in physics ; 114 SP - 93 EP - 97 PB - Springer CY - Berlin ER - TY - JOUR A1 - Müller-Veggian, Mattea A1 - Rusowicz, Andreas A1 - Nguyen, Christoph A1 - Nour, Youness T1 - Biologische Auswertung von verschiedenen Bestrahlungsplanvarianten für Zielvolumina im Abdomenbereich mit einem hauseigenen Computerprogramm Y1 - 2007 N1 - TH.SS.A3.04 ; Dreiländertagung Medizinphysik 2007. Vom 25.-28. September 2007. Universität Bern, Schweiz. Abteilung für Medizinische Strahlenphysik SP - 6 EP - 7 ER - TY - JOUR A1 - Müller-Veggian, Mattea A1 - Protic, D. A1 - Krings, T. A1 - Niessen, S. T1 - Position-Sensitive Si(Li) Transmission Detectors for the EXL-Experiments at GSI-Darmstadt. JF - Scientific Report / GSi Gesellschaft für Schwerionenforschung, Darmstadt. 2007 (2007), H. 1 Y1 - 2007 SN - 0174-0814 N1 - Fair-Experiments-31; GSI Report 2007-1, June 2007 ; GSI Scientific Report 2006 SP - 33 ER -