title: In vitro study to simulate the intracardiac magnetohydrodynamic effect.
abstract: OBJECTIVE
  Blood flow causes induced voltages via the magnetohydrodynamic (MHD) effect distorting electrograms (EGMs) made during magnetic resonance imaging. To investigate the MHD effect in this context MHD voltages occurring inside the human heart were simulated in an in vitro model system inside a 1.5 T MR system.
  
  
  METHODS
  The model was developed to produce MHD signals similar to those produced by intracardiac flow and to acquire them using standard clinical equipment. Additionally, a new approach to estimate MHD distortions on intracardiac electrograms is proposed based on the analytical calculation of the MHD signal from MR phase contrast data.
  
  
  RESULTS
  The recorded MHD signals were similar in magnitude to intracardiac signals that would be measured by an electrogram of the left ventricle. The dependency of MHD signals on magnetic field strength and electrode separation was well reflected by an analytical model. MHD signals reconstructed from MR flow data were in excellent agreement with the MHD signal measured by clinical equipment.
  
  
  CONCLUSIONS
  The in vitro model allows investigation of MHD effects on intracardiac electrograms. A phase contrast MR scan was successfully applied to characterize and estimate the MHD distortion on intracardiac signals allowing correction of these effects.
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors.forename: Waltraud B
authors.initials: WB
authors.lastname: Buchenberg
authors.affiliation: Department of Physics and Mathematics, Freiburg Center for Data Analysis and Modeling, University of Freiburg, Freiburg, Germany.|Department of Physics, University of Freiburg, Freiburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Mader
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Hoppe
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors.forename: Ramona
authors.initials: R
authors.lastname: Lorenz
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Menza
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Büchert
authors.affiliation: Department of Physics and Mathematics, Freiburg Center for Data Analysis and Modeling, University of Freiburg, Freiburg, Germany.|Department of Physics, University of Freiburg, Freiburg, Germany.|BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Timmer
authors.affiliation: Department of Radiology, University Medical Center Freiburg, Medical Physics, Freiburg, Germany.|Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Bern, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Jung
mesh_terms: D054849:Cardiac Electrophysiology; D004562:Electrocardiography / Q000379:methods*; D004867:Equipment Design; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted
keywords: electrophysiology; hemodynamics; in vitro model system; intracardiac electrograms; magnetohydrodynamic effect; phase contrast MRI