Experimental Estimation of Local SAR in a Multi-Transmit System

Ulrich Katscher¹, Christian Findeklee¹, Tobias Voigt²

SAR management is a widely discussed topic at high main fields, particularly in the framework of multi-transmit systems. Typically, local SAR is estimated via patient model simulations, which, however, are too extensive for clinical routine. This study investigates a possible alternative local SAR estimation by post-processing the RF transmit element's sensitivities. To this goal, the recently published approach "Electric Properties Tomography" was adapted for non-quadrature RF excitation, typically applied in multi-transmit systems, e.g., for RF shimming. Local SAR distributions obtained in phantom experiments with an 8-channel transmit system at 3T show a high correlation with corresponding local SAR simulations.