title: Cardiac pacemakers, ICDs, and loop recorder: evaluation of translational attraction using conventional ("long-bore") and "short-bore" 1.5- and 3.0-Tesla MR systems.
abstract: OBJECTIVE
  To evaluate magnet-related translational attraction for cardiac pacemakers, ICDs, and an insertable loop recorder in association with exposure to "long-bore" and "short-bore" 1.5- and 3.0-Tesla MR systems.
  
  
  METHODS
  Fourteen cardiac pacemakers, four ICDs, and one insertable loop recorder were evaluated for translational attraction using deflection angle tests performed at the points of the highest spatial gradients for long-bore and short-bore 1.5- and 3.0-Tesla MR systems according to ASTM guidelines.
  
  
  RESULTS
  Deflection angles ranged from 9-90 degrees for the long-bore and from 11-90 degrees for the short-bore 1.5-T MR system. Deflection angles ranged from 23-90 degrees for the long-bore and from 34-90 degrees for the short-bore 3.0-T MR system. Three of the cardiovascular implants exhibited deflection angles > or = 45 degrees (i.e., indicating that they are potentially unsafe for patients) on the long-bore and short-bore 1.5-T MR systems. Eight implants exhibited deflection angles > or = 45 degrees on the long-bore 3.0-T MR system, while 14 exhibited deflection angles > or = 45 degrees on the short-bore 3.0-T MR system. In general, deflection angles for these cardiovascular implants were significantly (p < 0.01) higher on 1.5- and 3.0-Tesla short-bore compared to the long-bore MR systems.
  
  
  CONCLUSIONS
  Several of the cardiovascular implants that underwent evaluation may be problematic for patients undergoing MR procedures using 1.5- and 3.0-T MR systems because of risks associated with magnet-related movements. Obviously, additional MR safety issues must also be considered for these implants.
authors.affiliation: University of Southern California, Keck School of Medicine, and Institute for Magnetic Resonance, Safety, Education, and Research, Los Angeles, California, USA.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Shellock
authors.forename: Jean A
authors.initials: JA
authors.lastname: Tkach
authors.forename: Paul M
authors.initials: PM
authors.lastname: Ruggieri
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Masaryk
mesh_terms: D002318:Cardiovascular Diseases / Q000628:therapy; D017147:Defibrillators, Implantable / Q000592:standards; D004867:Equipment Design / Q000592:standards; D004869:Equipment Safety / Q000592:standards; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards; D010138:Pacemaker, Artificial / Q000592:standards; D016896:Treatment Outcome