Fig. 5.

Comparison of ³¹P B₁ maps (in the axial plane) of selected human calf muscle (left panel) in another subject. (A) shows the schematic placement of 4 uHDC blocks (blue) around the leg. The B₁ maps (the scale bar is in an arbitrary unit, a.u.) with the uHDC blocks (B, E) show large enhancement of B₁ efficiency compared to the case without the uHDC blocks (C, F). The B₁ ratio maps (D, E) represent the B₁ with uHDC over B₁ without uHDC.