Magnetic resonance imaging in individuals with cardiovascular implantable electronic devices

Magnetic resonance (MR) imaging has unparalleled soft-tissue imaging capabilities. The presence of devices such as pacemakers and implantable cardioverter-defibrillators (ICDs), however, was historically considered a contraindication to MR imaging. We summarize the potential hazards of the device-MR environment interaction, and present updated information regarding in vitro and in vivo experiments suggesting that certain pacemaker and ICD systems may indeed be MR-safe. Recent reports on several hundred patients with implantable pacemakers and ICDs who underwent MR scan safety indicate that, under certain conditions, individuals with these implanted systems may benefit from MR imaging. We believe that, on a case-by-case basis, the diagnostic benefit from MR imaging outweighs the presumed risks for some pacemaker and ICD patients. Thus for some patients, the risks presented by MR imaging under specific, characterized scanning and monitoring conditions may be acceptable given the diagnostic benefit of this powerful imaging modality. This may have major clinical implications on current imaging practice. A strategy for the performance of MR imaging in these individuals is proposed.