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Abstract #2900

Multi-Dimensional Refocusing Pulses for Parallel Transmission by Optimal Control

Weiran Deng1, Cungeng Yang1, V. Andrew Stenger1

1Medicine, University of Hawaii John A. Burns School of Medicine, Honolulu, HI, United States

Multi-dimensioanl refocusing RF pulses for parallel transmission are useful for spin-echo imaging at high magnetic fields. The design of such pulses is challenging because it requires a nonlinear approach to "pancake-flip" the spins with different in-plane phases. We designed a refocusing pulse with 2D spiral k-space trajectory for eight transmitters using a two-process optimal control approach that flips the Y-component of spins from the +Y to -Y direction and leaves the X-component intact. The performance of the pulse was demonstrated using Bloch equation simulation.