Yi-Cheng Hsu1, I-Liang Chern1, Fa-Hsuan Lin2, 3
1National Taiwan University, Taipei, Taiwan; 2National Taiwan University, Taiwan; 3Massachusetts General Hospital, United States
Using one single transmitter and quadratic magnetic fields, we propose the spatially selective RF quadratic field excitation (QEF) to 1) efficiently excite small FOV and 2) to generate a distribution of Mxy to compensate the B1 inhomogeneity in high field MRI. Specifically, compared to using linear gradients and 25 spokes, QFE is more than 2 times faster to complete the 1/3 FOV excitation with the improved accuracy of the excitation profile by 2.2-fold. In addition, QFE is 2.5 times faster than fast-Kz to excite a slice with in-plane circular symmetric flip angle distribution complementary to high field B1 inhomogeneity.