William A. Grissom1, Adam B. Kerr1, Pascal P. Stang1, Michael Lustig2, Greig C. Scott1, John M. Pauly1
1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Electrical Engineering, University of California, Berkeley, Berkeley, CA, United States
Multidimensional and parallel excitation pulses are highly sensitive to trajectory imperfections resulting from eddy currents and gradient amplifier nonlinearity. It has been recently proposed to solve this by redesigning RF pulses on measured trajectories; however, this approach is not compatible with RF pulse design methods in which the RF and gradients are designed jointly. We introduce an iterative technique for gradient preemphasis for multidimensional and parallel excitation. The method is capable of overcoming gradient amplifier non-linearities, and obviates the need to redesign pulses on a measured trajectory.