Tianrui Luo1, Douglas C. Noll1, Jeffrey A. Fessler1, and Jon-Fredrik Nielsen1
1University of Michigan, Ann Arbor, MI, United States
1University of Michigan, Ann Arbor, MI, United States
We accelerated an auto-differentiable Bloch-simulator based joint RF and gradient design algorithm with a two stage strategy: 1) fast coarse dwell time design; 2) fine dwell time tuning. It substantially shortens designs, enabling such approaches for online applications.
Comparison of designs on outer volume excitation objective (OV90). Our proposed method is much faster than the method in [2] (3 min vs 8.5 min). The optimized pulse waveforms and the k-space trajectory resemble that of method [2].
Comparison of simulated excitation profiles for the pulses in Fig. 2. The goal is to excite only the spins in the outer volume. In terms of NRMSE, our proposed method performance is slightly better than that of method [2].