Tailored Excitation Using Non-Linear B0-Shims

Qi Duan¹, Peter van Gelderen¹, Jeff H. Duyn¹

This abstract proposes an alternative approach to shorten multi-dimensional excitation by utilizing non-linear spatial variations in the stationary (B₀) magnetic field during a B₀-sensitive excitation pulse. As initial demonstration, the method was applied to 2D gradient echo (GE) MRI of human brain at 7T. Using B0 shims with up to second order spatial dependence, it is demonstrated that root-mean-squared flip angle variation can be reduced from 20% to 11% with RF pulse lengths that are practical for general GE imaging applications without requiring parallel excitation.