Fig. 6.

Evaluation of our approach in 3T body simulations (eight Tx channels) for MLS design of spoke pulses. The worst case SAR was calculated for a maximum deviation of 5% for the amplitude and 2.5° in the phase. The first row shows the original pulses as well as those modified to be robust in the presence of transmit errors. The second row shows the SAR distribution across VOPs of the original pulse (in blue) and its worst-case SAR version (in red). Horizontal black lines indicate the FDA SAR limits. The third row shows MIPs of the worst-case SAR distribution of all pulses. In the last row the achieved flip angle maps are displayed. These results show that our method produces RF pulses that are robust even in the presence of worst-case errors in the transmit RF chain. The price to pay for this additional safety-margin is a small loss in the flip-angle distribution that becomes almost negligible for the two-spoke pulse design.