@misc{GraesslRenzHezeletal.2012,
  author    = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Frauenrath, Tobias and Pfeiffer, Harald and Hoffmann, Werner and Kellmann, Peter and Martin, Conrad and Niendorf, Thoralf},
  title     = {Design, evaluation and application of a modular 32 channel transmit/receive surface coil array for cardiac MRI at 7T},
  series = {2012 ISMRM Annual Meeting Proceedings},
  journal   = {2012 ISMRM Annual Meeting Proceedings},
  issn      = {1545-4428},
  year      = {2012},
  abstract  = {Cardiac MR (CMR) at ultrahigh (≥7.0 T) fields is regarded as one of the most challenging MRI applications. At 7.0 T image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Detrimental effects bear the potential to spoil the signal-to-noise (SNR) and contrast-to-noise (CNR) benefits of cardiac MR (CMR) at 7.0 T. B₁⁺-inhomogeneities and signal voids represent the main challenges. Various pioneering coil concepts have been proposed to tackle these issues, enabling cardiac MRI at 7.0 T. This includes a trend towards an ever larger number of transmit and receive channels. This approach affords multi-dimensional B₁⁺ modulations to improve B₁⁺ shimming performance and to enhance RF efficiency. Also, parallel imaging benefits from a high number of receive channels enabling two-dimensional acceleration. Realizing the limitations of existing coil designs tailored for UHF CMR and recognizing the opportunities of a many element TX/RX channel architecture this work proposes a modular, two dimensional 32-channel transmit and receive array using loop elements and examines its efficacy for enhanced B¹+ homogeneity and improved parallel imaging performance.},
  language  = {en}
}
@article{MartinFrauenrathOezerdemetal.2011,
  author    = {Martin, Conrad and Frauenrath, Tobias and {\"O}zerdem, Celal and Renz, Wolfgang and Niendorf, Thoralf},
  title     = {Development and evaluation of a small and mobile Magneto Alert Sensor (MALSE) to support safety requirements for magnetic resonance imaging},
  series = {European Radiology},
  volume    = {21},
  journal   = {European Radiology},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  issn      = {1432-1084},
  doi       = {10.1007/s00330-011-2153-z},
  pages     = {2187 -- 2192},
  year      = {2011},
  abstract  = {Objective The purpose of this study is to (i) design a small and mobile Magnetic field ALert SEnsor (MALSE), (ii) to carefully evaluate its sensors to their consistency of activation/deactivation and sensitivity to magnetic fields, and (iii) to demonstrate the applicability of MALSE in 1.5 T, 3.0 T and 7.0 T MR fringe field environments. Methods MALSE comprises a set of reed sensors, which activate in response to their exposure to a magnetic field. The activation/deactivation of reed sensors was examined by moving them in/out of the fringe field generated by 7TMR. Results The consistency with which individual reed sensors would activate at the same field strength was found to be 100\% for the setup used. All of the reed switches investigated required a substantial drop in ambient magnetic field strength before they deactivated. Conclusions MALSE is a simple concept for alerting MRI staff to a ferromagnetic object being brought into fringe magnetic fields which exceeds MALSEs activation magnetic field. MALSE can easily be attached to ferromagnetic objects within the vicinity of a scanner, thus creating a barrier for hazardous situations induced by ferromagnetic parts which should not enter the vicinity of an MR-system to occur.},
  language  = {en}
}
@misc{MartinFrauenrathZerdemetal.2011,
  author    = {Martin, Conrad Steven and Frauenrath, Tobias and Zerdem, Celal and Renz, Wolfgang and Niendorf, Thoralf},
  title     = {Evaluation of Magneto Alert Sensor (MALSE) to Improve MR Safety by Decreasing the Incidence of Ferromagnetic Projectile Accidents},
  series = {2011 ISMRM Annual Meeting Proceedings},
  journal   = {2011 ISMRM Annual Meeting Proceedings},
  issn      = {1545-4428},
  year      = {2011},
  abstract  = {The magnetic forces of fringe magnetic fields of MR systems on ferromagnetic components can impose a severe patient, occupational health and safety hazard. MRI accidents are listed as number 9 of the top 10 risks in modern medicine. With the advent of ultrahigh field MR systems including passively shielded magnet versions, this risk, commonly known as the missile or projectile effect is even more pronounced. A strategy employing magnetic field sensors which can be attached to ferromagnetic objects that are commonly used in a clinical environment is conceptually appealing for the pursuit of reducing the risk of ferromagnetic projectile accidents.},
  language  = {en}
}