Model-based dynamic off-resonance correction for improved accelerated fMRI in awake behaving nonhuman primates.

ABSTRACT:

Purpose

To estimate dynamic off-resonance due to vigorous body motion in accelerated fMRI of awake behaving nonhuman primates (NHPs) using the echo-planar imaging reference navigator, in order to attenuate the effects of time-varying off-resonance on the reconstruction.

Methods

In NHP fMRI, the animal's head is usually head-posted, and the dynamic off-resonance is mainly caused by motion in body parts that are distant from the brain and have low spatial frequency. Hence, off-resonance at each frame can be approximated as a spatially linear perturbation of the off-resonance at a reference frame, and is manifested as a relative linear shift in k-space. Using GRAPPA operators, we estimated these shifts by comparing the navigator at each time frame with that at the reference fra

SUBMITTER: Shahdloo M 

PROVIDER: S-EPMC9306555 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature