Joint design of large-tip-angle parallel RF pulses and blipped gradient trajectories.

ABSTRACT:

Purpose

To design multichannel large-tip-angle kT-points and spokes radiofrequency (RF) pulses and gradient waveforms for transmit field inhomogeneity compensation in high field magnetic resonance imaging.

Theory and methods

An algorithm to design RF subpulse weights and gradient blip areas is proposed to minimize a magnitude least-squares cost function that measures the difference between realized and desired state parameters in the spin domain, and penalizes integrated RF power. The minimization problem is solved iteratively with interleaved target phase updates, RF subpulse weights updates using the conjugate gradient method with optimal control-based derivatives, and gradient blip area updates using the conjugate gradient method. Two-channel parallel transmit simulations

SUBMITTER: Cao Z 

PROVIDER: S-EPMC4624053 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature