RF Shimming in Human Torso with the Multi-Mode Coaxial Waveguide at 7T

Anna Andreychenko¹, Vincent O. Boer¹, Jan J.W. Lagendijk¹, Peter R. Luijten¹, Cornelis A.T. van den Berg¹

Volume coils are attractive RF transmit systems as they provide a flexible means of RF excitation for the whole body. As an alternative to volume coils a coaxial waveguide concept was proposed recently. Remarkable RF shimming performance of a multi-mode coaxial waveguide was demonstrated for the head at 7T. Here the performance of the multi-mode coaxial waveguide for body torso was investigated in terms of the achieved B1+ efficiency, homogeneity and RF safety constraints. Provided large excitation coverage it was shown that the multi-mode coaxial waveguide could be applied for efficient overall and targeted 3D RF shimming in body torso.