Figure 5:

10g SAR analysis of the various transmit scenarios. The white brackets indicate the region over which the mean flip angle was calculated. For the spokes pulse (right column), this region corresponded to the optimization region, which was a single axial slice. In the left column, SAR without the helmet is displayed. In the middle column, SAR maps with the uHDC helmet are displayed, with normalization by both flip angle and whole body SAR considered. The right column displays the SAR map induced by the spokes pulse. In quadrature mode, whole body SAR was lowered significantly with the uHDC helmet present in the flip angle normalized case, though a local region of elevated SAR was observed at the top of the head. The whole body SAR increased by 21.5% relative to the case without the helmet when a spokes pulse was utilized, alongside a further amplification of the SAR at the apex of the head.