RF Shimming of the Neck Using a 2 & a 4-Channel Travelling Wave Neck Array at 7T MRI

Wouter Koning¹, Johanneke H. Bluemink¹, Vincent O. Boer¹, Alexander Raaijmakers¹, Anke Henning², Jaco J.M. Zwanenburg¹, Cornelis A.T. van den Berg¹, Peter R. Luijten¹, Dennis J.W. Klomp¹

For neck imaging with 7T MRI the versatility of 2 and a 4 channel transmit array was evaluated. The array consists of a neck pillow filled with D2O. The pillow acts as a leaky waveguide in which a wave is fed by 2 or 4 radiative antennas. RF shimming is used to demonstrate versatility: focussing the RF with the 2 channel system allows imaging of carotids and spine. Going from 2 to 4 channels allows for homogeneity improvement and reduction of SAR.