Investigation of the factors responsible for burns during MRI

Numerous reported burn injuries have been sustained during clinical AM proc edures. The aim of this study was to investigate the possible factors that may be responsible for such burns. Experiments were performed to investigat e three possible mechanisms for causing heating in copper wire during AM: d irect electromagnetic induction in a conductive loop, induction in a resona nt conducting loop, and electric field resonant coupling with a wire (the a ntenna effect). Maximum recorded temperature rises were 0.6 degreesC for th e loop, 61.1 degreesC for the resonant loop, and 63.5 degreesC for the reso nant antenna. These experimental findings suggest that, contrary to common belief, it is unlikely that direct induction in a conductive loop will resu lt in thermal injury. Burn incidents are more likely to occur due to the fo rmation of resonant conducting loops and from extended wires forming resona nt antenna. The characteristics of resonance should be considered when form ulating safety guidelines. (C) 2001 Wiley-Liss, Inc.