Specific absorption rate as a poor indicator of magnetic resonance-related implant heating.

Recent publications of the magnetic resonance safety profile of neurostimulators, cardiac pacemakers, and other implanted devices imply that these devices are no longer a contraindication for magnetic resonance imaging. It is very promising that patients who have these implanted devices may in the future no longer be denied an important diagnostic modality. On the other hand, the safety recommendations given in a number of publications included the maximum permissible whole-body specific absorption rate (SAR). This is one factor indicating potential heating, but there are a number of other factors that may have an even higher impact on the potential heating of tissue in the vicinity of leads or implanted devices. Using only the whole-body SAR as a recommendation for a safety profile is potentially dangerous.