Assessment and correction of macroscopic field variations in 2D spoiled gradient-echo sequences.

ABSTRACT:

Purpose

To model and correct the dephasing effects in the gradient-echo signal for arbitrary RF excitation pulses with large flip angles in the presence of macroscopic field variations.

Methods

The dephasing of the spoiled 2D gradient-echo signal was modeled using a numerical solution of the Bloch equations to calculate the magnitude and phase of the transverse magnetization across the slice profile. Additionally, regional variations of the transmit RF field and slice profile scaling due to macroscopic field gradients were included. Simulations, phantom, and in vivo measurements at 3 T were conducted for R2∗ and myelin water fraction (MWF) mapping.

Results

The influence of macroscopic field gradients on R2∗ and myelin water fraction estimation can be substantially red

SUBMITTER: Soellradl M 

PROVIDER: S-EPMC7216950 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature