@inproceedings{BitzKraffOrzadaetal.2010,
  author    = {Bitz, Andreas and Kraff, O. and Orzada, S. and Maderwald, S. and Brote, I. and Ladd, M.},
  title     = {Experimental and Numerical Assessment of RF Safety of Transmit Coils at 7 Tesla},
  series = {ISMRM workshop on MR safety 2010 : RF heating of the human in MRI : workshop series. The Washington County Historic Courthouse, Stillwater, Minnesota, USA, 15 - 17 October 2010},
  booktitle = {ISMRM workshop on MR safety 2010 : RF heating of the human in MRI : workshop series. The Washington County Historic Courthouse, Stillwater, Minnesota, USA, 15 - 17 October 2010},
  isbn      = {978-1-62276-088-6},
  pages     = {195},
  year      = {2010},
  language  = {en}
}
@article{NoureddineBitzLaddetal.2015,
  author    = {Noureddine, Yacine and Bitz, Andreas and Ladd, Mark E. and Th{\"u}rling, Markus and Ladd, Susanne C. and Schaefers, Gregor and Kraff, Oliver},
  title     = {Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study},
  series = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  volume    = {28},
  journal   = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  number    = {6},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1352-8661},
  doi       = {10.1007/s10334-015-0499-y},
  pages     = {577 -- 590},
  year      = {2015},
  language  = {en}
}
@article{SchmidtForkmannSchultzetal.2019,
  author    = {Schmidt, Katharina and Forkmann, Katarina and Schultz, Heidrun and Gratz, Marcel and Bitz, Andreas and Wiech, Katja and Bingel, Ulrike},
  title     = {Enhanced Neural Reinstatement for Evoked Facial Pain Compared With Evoked Hand Pain},
  series = {The Journal of Pain},
  journal   = {The Journal of Pain},
  number    = {In Press, Corrected Proof},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1526-5900},
  doi       = {10.1016/j.jpain.2019.03.003},
  year      = {2019},
  language  = {en}
}
@article{ProchnowGebingLadageetal.2011,
  author    = {Prochnow, Nora and Gebing, Tina and Ladage, Kerstin and Krause-Finkeldey, Dorothee and Ourdi, Abessamad El and Bitz, Andreas and Streckert, Joachim and Hansen, Volkert and Dermietzel, Rolf},
  title     = {Electromagnetic field effect or simply stress? Effects of UMTS exposure on hippocampal longterm plasticity in the context of procedure related hormone release},
  series = {PLoS one},
  volume    = {6},
  journal   = {PLoS one},
  number    = {5},
  publisher = {PLOS},
  address   = {San Francisco},
  doi       = {10.1371/journal.pone.0019437},
  pages     = {e19437},
  year      = {2011},
  abstract  = {Harmful effects of electromagnetic fields (EMF) on cognitive and behavioural features of humans and rodents have been controversially discussed and raised persistent concern about adverse effects of EMF on general brain functions. In the present study we applied radio-frequency (RF) signals of the Universal Mobile Telecommunications System (UMTS) to full brain exposed male Wistar rats in order to elaborate putative influences on stress hormone release (corticosteron; CORT and adrenocorticotropic hormone; ACTH) and on hippocampal derived synaptic long-term plasticity (LTP) and depression (LTD) as electrophysiological hallmarks for memory storage and memory consolidation. Exposure was computer controlled providing blind conditions. Nominal brain-averaged specific absorption rates (SAR) as a measure of applied mass-related dissipated RF power were 0, 2, and 10 W/kg over a period of 120 min. Comparison of cage exposed animals revealed, regardless of EMF exposure, significantly increased CORT and ACTH levels which corresponded with generally decreased field potential slopes and amplitudes in hippocampal LTP and LTD. Animals following SAR exposure of 2 W/kg (averaged over the whole brain of 2.3 g tissue mass) did not differ from the sham-exposed group in LTP and LTD experiments. In contrast, a significant reduction in LTP and LTD was observed at the high power rate of SAR (10 W/kg). The results demonstrate that a rate of 2 W/kg displays no adverse impact on LTP and LTD, while 10 W/kg leads to significant effects on the electrophysiological parameters, which can be clearly distinguished from the stress derived background. Our findings suggest that UMTS exposure with SAR in the range of 2 W/kg is not harmful to critical markers for memory storage and memory consolidation, however, an influence of UMTS at high energy absorption rates (10 W/kg) cannot be excluded.},
  language  = {en}
}
@inproceedings{BitzElOuardiStreckertetal.2005,
  author    = {Bitz, Andreas and El Ouardi, A. and Streckert, J. and Hansen, V.},
  title     = {Efficient calculation of human exposure in front of base station antennas by a combination of the FDTD and Hybrid(2)-method},
  series = {Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility, Topical Meeting on Biomedical EMC, Zurich, Switzerland, February 2005},
  booktitle = {Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility, Topical Meeting on Biomedical EMC, Zurich, Switzerland, February 2005},
  publisher = {ETH Zentrum},
  address   = {Z{\"u}rich},
  isbn      = {3-9521199-9-7},
  pages     = {115 -- 118},
  year      = {2005},
  language  = {en}
}
@article{FrankeStreckertBitzetal.2005,
  author    = {Franke, Helmut and Streckert, Joachim and Bitz, Andreas and Goeke, Johannes and Hansen, Volkert and Ringelstein, E. Bernd and Nattk{\"a}mper, Heiner and Galle, Hans-Joachim and St{\"o}gbauer, Florian},
  title     = {Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro},
  series = {Radiation Research},
  volume    = {164},
  journal   = {Radiation Research},
  number    = {3},
  issn      = {1938-5404},
  doi       = {10.1667/RR3424.1},
  pages     = {258 -- 269},
  year      = {2005},
  language  = {en}
}
@article{LerchlKruegerNiehausetal.2008,
  author    = {Lerchl, Alexander and Kr{\"u}ger, Heike and Niehaus, Michael and Streckert, Joachim R. and Bitz, Andreas and Hansen, Volkert},
  title     = {Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus)},
  series = {Journal of Pineal Research},
  volume    = {44},
  journal   = {Journal of Pineal Research},
  number    = {3},
  issn      = {1600-079X},
  doi       = {10.1111/j.1600-079X.2007.00522.x},
  pages     = {267 -- 272},
  year      = {2008},
  language  = {en}
}
@article{RietschBrunheimOrzadaetal.2019,
  author    = {Rietsch, Stefan H. G. and Brunheim, Sascha and Orzada, Stephan and Voelker, Maximilian N. and Maderwald, Stefan and Bitz, Andreas and Gratz, Marcel and Ladd, Mark E. and Quick, Harald H.},
  title     = {Development and evaluation of a 16-channel receive-only RF coil to improve 7T ultra-high field body MRI with focus on the spine},
  series = {Magnetic Resonance in Medicine},
  journal   = {Magnetic Resonance in Medicine},
  number    = {Early view},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.27731},
  year      = {2019},
  language  = {en}
}
@article{BitzFelderWittig2013,
  author    = {Bitz, Andreas and Felder, Jorg and Wittig, Tilmann},
  title     = {Designing MRI Coils with Aid of Simulation},
  series = {Microwaves \& RF},
  volume    = {52},
  journal   = {Microwaves \& RF},
  number    = {7},
  publisher = {Penton},
  address   = {Cleveland, Ohio},
  issn      = {0745-2993},
  pages     = {56},
  year      = {2013},
  language  = {en}
}
@article{ChenSchoembergKraffetal.2016,
  author    = {Chen, Bixia and Schoemberg, Tobias and Kraff, Oliver and Dammann, Philipp and Bitz, Andreas and Schlamann, Marc and Quick, Harald H. and Ladd, Mark E. and Sure, Ulrich and Wrede, Karsten H.},
  title     = {Cranial fixation plates in cerebral magnetic resonance imaging: a 3 and 7 Tesla in vivo image quality study},
  series = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  volume    = {29},
  journal   = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  number    = {3},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1352-8661},
  doi       = {10.1007/s10334-016-0548-1},
  pages     = {389 -- 398},
  year      = {2016},
  abstract  = {Objective This study assesses and quantifies impairment of postoperative magnetic resonance imaging (MRI) at 7 Tesla (T) after implantation of titanium cranial fixation plates (CFPs) for neurosurgical bone flap fixation. Materials and methods The study group comprised five patients who were intra-individually examined with 3 and 7 T MRI preoperatively and postoperatively (within 72 h/3 months) after implantation of CFPs. Acquired sequences included T₁-weighted magnetization-prepared rapid-acquisition gradient-echo (MPRAGE), T₂-weighted turbo-spin-echo (TSE) imaging, and susceptibility-weighted imaging (SWI). Two experienced neurosurgeons and a neuroradiologist rated image quality and the presence of artifacts in consensus reading. Results Minor artifacts occurred around the CFPs in MPRAGE and T2 TSE at both field strengths, with no significant differences between 3 and 7 T. In SWI, artifacts were accentuated in the early postoperative scans at both field strengths due to intracranial air and hemorrhagic remnants. After resorption, the brain tissue directly adjacent to skull bone could still be assessed. Image quality after 3 months was equal to the preoperative examinations at 3 and 7 T. Conclusion Image quality after CFP implantation was not significantly impaired in 7 T MRI, and artifacts were comparable to those in 3 T MRI.},
  language  = {en}
}
@article{UmutluBitzMaderwaldetal.2013,
  author    = {Umutlu, Lale and Bitz, Andreas and Maderwald, Stefan and Orzada, Stephan and Kinner, Sonja and Kraff, Oliver and Brote, Irina and Ladd, Susanne C. and Schroeder, Tobias and Forsting, Michael},
  title     = {Contrast-enhanced ultra-high-field liver MRI: a feasibility trial},
  series = {European Journal of Radiology},
  volume    = {82},
  journal   = {European Journal of Radiology},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0720-048X},
  doi       = {10.1016/j.ejrad.2011.07.004},
  pages     = {760 -- 767},
  year      = {2013},
  language  = {en}
}
@inproceedings{BitzAlaydrusStreckertetal.2002,
  author    = {Bitz, Andreas and Alaydrus, M. and Streckert, J. and Hansen, V.},
  title     = {Combination of the hybrid/sup [2]/-method and the FDTD-method for solution of boundary value problems with electrically large and high-resolution bodies},
  series = {IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313) 2002 : San Antonio, TX, USA, 16-21 June},
  booktitle = {IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313) 2002 : San Antonio, TX, USA, 16-21 June},
  publisher = {IEEE},
  address   = {Piscataway, NJ},
  isbn      = {0-7803-7330-8},
  doi       = {10.1109/APS.2002.1018209},
  pages     = {278 -- 281},
  year      = {2002},
  language  = {en}
}
@inproceedings{BitzAlaydrusStreckertetal.2001,
  author    = {Bitz, Andreas and Alaydrus, M. and Streckert, J. and Hansen, V.W.},
  title     = {Base station antennas embedded in complex environments: rf exposure in controlled areas},
  series = {23rd BEMS Annual Meeting, St. Paul, Minnesota, USA, 49-50, June 2001},
  booktitle = {23rd BEMS Annual Meeting, St. Paul, Minnesota, USA, 49-50, June 2001},
  publisher = {Bioelectromagnetics Society},
  address   = {Frederick, MD},
  pages     = {49 -- 50},
  year      = {2001},
  language  = {en}
}
@article{SchlamannYoonMaderwaldetal.2009,
  author    = {Schlamann, M. and Yoon, M.-S. and Maderwald, S. and Pietrzyk, T. and Bitz, Andreas and Gerwig, M. and Forsting, M. and Ladd, S. C. and Ladd, M. E. and Kastrup, O.},
  title     = {Auswirkungen der Magnetresonanztomografie auf die Elektrophysiologie des motorischen Kortex: eine Studie mit transkranieller Magnetstimulation},
  series = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren},
  volume    = {181},
  journal   = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren},
  number    = {3},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {1438-9029},
  doi       = {10.1055/s-0028-1109038},
  pages     = {215 -- 219},
  year      = {2009},
  language  = {de}
}
@inproceedings{BitzKraffOrzadaetal.2012,
  author    = {Bitz, Andreas and Kraff, O. and Orzada, S. and Maderwald, S. and Brote, I. and Johst, S. and Ladd, E.},
  title     = {Assessment of RF Safety of Transmit Coils at 7 Tesla by Experimental and Numerical Procedures (490.)},
  series = {19th annual ISMRM scientific meeting and exhibition 2011 : Montreal, Quebec, Canada, 7 - 13 May 2011},
  booktitle = {19th annual ISMRM scientific meeting and exhibition 2011 : Montreal, Quebec, Canada, 7 - 13 May 2011},
  number    = {Volume 1},
  publisher = {Curran},
  address   = {Red Hook, NY},
  isbn      = {978-1-61839-284-8},
  pages     = {475},
  year      = {2012},
  language  = {en}
}
@article{OrzadaBitzJohstetal.2017,
  author    = {Orzada, Stephan and Bitz, Andreas and Johst, S{\"o}ren and Gratz, Marcel and V{\"o}lker, Maximilian N. and Kraff, Oliver and Abuelhaija, Ashraf and Fiedler, Thomas M. and Solbach, Klaus and Quick, Harald H. and Ladd, Mark E.},
  title     = {Analysis of an integrated 8-Channel Tx/Rx body array for use as a body coil in 7-Tesla MRI},
  series = {Frontiers in Physics},
  volume    = {5},
  journal   = {Frontiers in Physics},
  number    = {Jun},
  issn      = {2296-424X},
  doi       = {10.3389/fphy.2017.00017},
  year      = {2017},
  language  = {en}
}
@article{KraffBitzDammannetal.2010,
  author    = {Kraff, Oliver and Bitz, Andreas and Dammann, Philipp and Ladd, Susanne C. and Ladd, Mark E. and Quick, Harald H.},
  title     = {An eight-channel transmit/receive multipurpose coil for musculoskeletal MR imaging at 7 T},
  series = {Medical Physics},
  volume    = {37},
  journal   = {Medical Physics},
  number    = {12},
  publisher = {Wiley},
  address   = {Hoboken, NJ},
  issn      = {2473-4209},
  doi       = {10.1118/1.3517176},
  pages     = {6368 -- 6376},
  year      = {2010},
  abstract  = {Purpose: MRI plays a leading diagnostic role in assessing the musculoskeletal (MSK) system and is well established for most questions at clinically used field strengths (up to 3 T). However, there are still limitations in imaging early stages of cartilage degeneration, very fine tendons and ligaments, or in locating nerve lesions, for example. 7 T MRI of the knee has already received increasing attention in the current published literature, but there is a strong need to develop new radiofrequency (RF) coils to assess more regions of the MSK system. In this work, an eight-channel transmit/receive RF array was built as a multipurpose coil for imaging some of the thus far neglected regions. An extensive coil characterization protocol and first in vivo results of the human wrist, shoulder, elbow, knee, and ankle imaged at 7 T will be presented. Methods: Eight surface loop coils with a dimension ofurn:x-wiley:00942405:media:mp7176:mp7176-math-0001 were machined from FR4 circuit board material. To facilitate easy positioning, two coil clusters, each with four loop elements, were combined to one RF transmit/receive array. An overlapped and shifted arrangement of the coil elements was chosen to reduce the mutual inductance between neighboring coils. A phantom made of body-simulating liquid was used for tuning and matching on the bench. Afterward, the S-parameters were verified on a human wrist, elbow, and shoulder. For safety validation, a detailed compliance test was performed including full wave simulations of the RF field distribution and the corresponding specific absorption rate (SAR) for all joints. In vivo images of four volunteers were assessed with gradient echo and spin echo sequences modified to obtain optimal image contrast, full anatomic coverage, and the highest spatial resolution within a reasonable acquisition time. The performance of the RF coil was additionally evaluated by in vivo B1 mapping. Results: A comparison of B1 per unit power, flip angle distribution, and anatomic images showed a fairly homogeneous excitation for the smaller joints (elbow, wrist, and ankle), while for the larger joints, the shoulder and especially the knee, B1 inhomogeneities and limited penetration depth were more pronounced. However, the greater part of the shoulder joint could be imaged.In vivo images rendered very fine anatomic details such as fascicles of the median nerve and the branching of the nerve bundles. High-resolution images of cartilage, labrum, and tendons could be acquired. Additionally, turbo spin echo (TSE) and inversion recovery sequences performed very well. Conclusions: This study demonstrates that the concept of two four-channel transmit/receive RF arrays can be used as a multipurpose coil for high-resolutionin vivo MR imaging of the musculoskeletal system at 7 T. Not only gradient echo but also typical clinical and SAR-intensive sequences such as STIR and TSE performed well. Imaging of small structures and peripheral nerves could in particular benefit from this technique.},
  language  = {en}
}
@article{KraffBitzKruszonaetal.2009,
  author    = {Kraff, Oliver and Bitz, Andreas and Kruszona, Stefan and Orzada, Stephan and Schaefer, Lena C. and Theysohn, Jens M. and Maderwald, Stefan and Ladd, Mark E. and Quick, Harald H.},
  title     = {An eight-channel phased array RF coil for spine MR imaging at 7 T},
  series = {Investigative Radiology},
  volume    = {44},
  journal   = {Investigative Radiology},
  number    = {11},
  publisher = {Lippincott Williams \& Wilkins},
  issn      = {1536-0210},
  doi       = {10.1097/RLI.0b013e3181b24ab7},
  pages     = {734 -- 740},
  year      = {2009},
  language  = {en}
}
@article{RietschPfaffenrotBitzetal.2017,
  author    = {Rietsch, Stefan H. G. and Pfaffenrot, Viktor and Bitz, Andreas and Orzada, Stephan and Brunheim, Sascha and Lazik-Palm, Andrea and Theysohn, Jens M. and Ladd, Mark E. and Quick, Harald H. and Kraff, Oliver},
  title     = {An 8-channel transceiver 7-channel receive RF coil setup for high SNR ultrahigh-field MRI of the shoulder at 7T},
  series = {Medical Physics},
  journal   = {Medical Physics},
  number    = {Article in press},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0094-2405},
  doi       = {10.1002/mp.12612},
  year      = {2017},
  language  = {en}
}
@inproceedings{BitzAlaydrusStreckertetal.2002,
  author    = {Bitz, Andreas and Alaydrus, M. and Streckert, J. and Hansen, V.W.},
  title     = {Absorption rates inside human body due to radiated electro-magnetic fields of multi-band base station antennas. Boundary value problems with electrically large and high-resolution bodies},
  series = {24th BEMS Annual Meeting, Quebec City, Quebec, Canada, 23 - 27 June 2002},
  booktitle = {24th BEMS Annual Meeting, Quebec City, Quebec, Canada, 23 - 27 June 2002},
  publisher = {Bioelectromagnetics Society},
  address   = {Frederick, MD},
  pages     = {40 -- 41},
  year      = {2002},
  language  = {en}
}