Abstract #4925

GrIP: Gradient Iterative Predistortion for Multidimensional and Parallel Excitation

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.