Stochastic-offset-enhanced restricted slice excitation and 180° refocusing designs with spatially non-linear ΔB₀ shim array fields.

ABSTRACT:

Purpose

Developing a general framework with a novel stochastic offset strategy for the design of optimized RF pulses and time-varying spatially non-linear ΔB₀ shim array fields for restricted slice excitation and refocusing with refined magnetization profiles within the intervals of the fixed voxels.

Methods

Our framework uses the decomposition property of the Bloch equations to enable joint design of RF-pulses and shim array fields for restricted slice excitation and refocusing with auto-differentiation optimization. Bloch simulations are performed independently on orthogonal basis vectors, Mx, My, and Mz, which enables designs for arbitrary initial magnetizations. Requirements for refocusing pulse designs are derived from the extended phase graph formalism obvia

SUBMITTER: Zhang M 

PROVIDER: S-EPMC10699120 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature