title: The Safety of MR Conditional Cochlear Implant at 1.5 Tesla Magnetic Resonance Imaging System.
abstract: In magnetic resonance imaging (MRI) examination of the patients with the cochlear implant, only limited data have a mention for safety information in the instruction manual supplied by the manufacturers. Therefore, imaging operators require more detailed safety information for implant device. We conducted detailed examination about displacement force, torque, and demagnetizing of the cochlear implant magnet based on American Society for Testing and Materials (ASTM) standard using the PULSAR and CONCERTO (MED-EL) with 1.5 tesla MRI system. As a result, the displacement force and the torque of the implant magnet were less than the numerical values descried in the manual. Therefore, these have almost no effect on the body under the condition described in a manual. In addition, the demagnetizing factor of the cochlear implant magnet occurred by a change magnetic field. The demagnetization depended on the direction of a line of magnetic force of the static magnetic field and the implant magnet. In conclusion, the operator must warn the position of the patients on inducing in the magnet room.
authors.affiliation: Department of Radiological Technology, Northern Fukushima Medical Center, Jinsenkai.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takahashi
authors.forename: Akio
authors.initials: A
authors.lastname: Ogura
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Shinya
authors.initials: S
authors.lastname: Seino
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kawai
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuda
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Doi
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsuchihashi
mesh_terms: D003054:Cochlear Implants / Q000592:standards; D004869:Equipment Safety; D006801:Humans; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D059346:Magnets; D019415:Torque