Slice-Selective B1 Phase Shimming at 9.4 Tesla

Jens Hoffmann¹, Juliane Budde¹, Gunamony Shajan¹, Rolf Pohmann¹

In this work, we demonstrate B₁ phase shimming in situ at 9.4 Tesla: A rapid calibration pre-scan provides B₁⁺ magnitude and phase maps that are used to predict the total field across the subject dependent on a phase configuration of choice. In addition, a GUI provides the option to select a region within a slice where the field is quickly and reliably optimized by a simulated annealing algorithm based on a suitable optimization criterion. The accuracy of this method is demonstrated in a saline phantom and used for B₁ shimming in the human brain.