Modeling the effect of in-plane magnetic field gradients on asymmetric spin-echo images with echo-planar imaging readout.

ABSTRACT:

Purpose

To describe the impact of macroscopic magnetic field gradients (MFGs) in the phase-encoding direction on MR images acquired with an asymmetric spin echo (ASE) sequence with echo-planar imaging (EPI) readout.

Methods

In EPI, the center of k-space is read out at a shifted time point in the presence of phase-encoding direction MFGs. The ASE signal equation was extended to account for a locally varying temporal offset τeff$$ {\tau}_{eff} $$ between the spin echo and echo time due to MFGs. The impact on estimated quantitative blood oxygen level dependent (qBOLD) parameters was assessed using simulations. A B0$$ {B}_0 $$ map and ASE images with four different phase-encoding directions and two different parallel-imaging factors were acquired from 2 healthy volunteers. A rob

SUBMITTER: Wallimann P 

PROVIDER: S-EPMC12393211 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature