In vivo B1-based SAR Determination in a Multi-transmit System with DREAM

A central issue of parallel RF transmission is the SAR management toensure patient safety. The additional degrees of freedom availablein parallel transmission hamper straight-forward SAR estimations asapplied for single channel transmission. As an alternative to the usually applied model-based SAR estimation, a new method has been proposed to estimate SAR from the acquired B1 maps. This B1-based SAR determination has been successfully tested for quadrature (single channel) excitation in vivo and non-quadrature (multi-channel) excitation in a phantom study. This study adapts B1-based SAR determination for non-quadrature excitation in vivo. To this goal, the local SAR inthighs and pelvis of a volunteer is investigated and compared withresults of corresponding FDTD simulations based on the same volunteer.