Electromagnetic and thermal modeling of SAR and temperature fields in tissue due to an RF decoupling coil

The finite difference time domain method is used to calculate the specific absorption rate (SAR) due to a butterfly surface coil in a realistic tissue model of the leg. The resulting temperature distribution and temperature c hanges are found using a finite difference solution to the bioheat transfer equation. Reasonable agreement is found between predicted temperature chan ges and those measured in vivo provided that the resulting hyperthermia doe s not induce noticeable changes in perfusion. The method is applicable to r adiofrequency dosimetry problems associated with high B-o field magnetic re sonance systems and where knowledge of spatial variation in SAR is importan t in assessing the safety of new magnetic resonance procedures. Magn Reson Med 42:183-192, 1999. (C) 1999 Wiley-Liss, Inc.