Loop-dipole block simulations of (a, d) peak voxel-wise SAR, (b, e) B1+ transmit efficiency (c, f) B1+ SAR efficiency are shown for dipole-only (blue), loop-only (purple) and loop-dipole combined (black) excitations. Plots in the top row show the impact of changing the relative phase of loop-dipole combined excitation. Plots in the bottom row investigate the impact of attenuating the loop excitation power compared to dipole in the loop-dipole B1+ efficiency phase optimized combined excitation.