title: Demagnetization of cochlear implants and temperature changes in 3.0T MRI environment.
abstract: OBJECTIVE
  To investigate the level of demagnetization of the magnets and temperature changes in cochlear implants (Cis) in a 3.0 tesla (3.0T) MRI.
  
  
  METHODS
  Experimental.
  
  
  METHODS
  Demagnetization and remagnetization measurements were done on magnets for different types of CIs. Temperature of different body and electrode sides was measured in the MRI environment.
  
  
  RESULTS
  Demagnetization of the magnets of the CI is dependent on the angle between the magnetic field of the CI magnet and the MRI. When this angle was greater than 80 degrees, relevant demagnetization occurred and sufficient remagnetization was not possible with the 3.0T MRI magnet. Maximum temperature rise was 0.5 degrees C.
  
  
  CONCLUSIONS
  Patients carrying CIs with non-removable magnets should not enter a 3.0T MRI device in a routine clinical setup. Under special conditions (angle between the two magnets less than 80 degrees) imaging in a 3.0T MRI may be possible without harming the patient or the implant.
authors.affiliation: Medical University of Hannover, Clinic for Otolaryngology, Hannover, Germany.
authors.forename: Omid
authors.initials: O
authors.lastname: Majdani
authors.forename: Martin
authors.initials: M
authors.lastname: Leinung
authors.forename: Thomas
authors.initials: T
authors.lastname: Rau
authors.forename: Arash
authors.initials: A
authors.lastname: Akbarian
authors.forename: Martin
authors.initials: M
authors.lastname: Zimmerling
authors.forename: Minoo
authors.initials: M
authors.lastname: Lenarz
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.forename: Robert
authors.initials: R
authors.lastname: Labadie
mesh_terms: D003054:Cochlear Implants; D000075202:Contraindications; D004567:Electrodes, Implanted; D055590:Electromagnetic Phenomena; D004869:Equipment Safety; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D013696:Temperature