Dynamic distortion correction for functional MRI using FID navigators.
Détails
ID Serval
serval:BIB_CBAFBDDF1BDF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Dynamic distortion correction for functional MRI using FID navigators.
Périodique
Magnetic resonance in medicine
ISSN
1522-2594 (Electronic)
ISSN-L
0740-3194
Statut éditorial
Publié
Date de publication
03/2021
Peer-reviewed
Oui
Volume
85
Numéro
3
Pages
1294-1307
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Publication Status: ppublish
Résumé
To develop a method for slice-wise dynamic distortion correction for EPI using rapid spatiotemporal B <sub>0</sub> field measurements from FID navigators (FIDnavs) and to evaluate the efficacy of this new approach relative to an established data-driven technique.
A low-resolution reference image was used to create a forward model of FIDnav signal changes to enable estimation of spatiotemporal B <sub>0</sub> inhomogeneity variations up to second order from measured FIDnavs. Five volunteers were scanned at 3 T using a 64-channel coil with FID-navigated EPI. The accuracy of voxel shift measurements and geometric distortion correction was assessed for experimentally induced magnetic field perturbations. The temporal SNR was evaluated in EPI time-series acquired at rest and with a continuous nose-touching action, before and after image realignment.
Field inhomogeneity coefficients and voxel shift maps measured using FIDnavs were in excellent agreement with multi-echo EPI measurements. The FID-navigated distortion correction accurately corrected image geometry in the presence of induced magnetic field perturbations, outperforming the data-driven approach in regions with large field offsets. In functional MRI scans with nose touching, FIDnav-based correction yielded temporal SNR gains of 30% in gray matter. Following image realignment, which accounted for global image shifts, temporal SNR gains of 3% were achieved.
Our proposed application of FIDnavs enables slice-wise dynamic distortion correction with high temporal efficiency. We achieved improved signal stability by leveraging the encoding information from multichannel coils. This approach can be easily adapted to other EPI-based sequences to improve temporal SNR for a variety of clinical and research applications.
A low-resolution reference image was used to create a forward model of FIDnav signal changes to enable estimation of spatiotemporal B <sub>0</sub> inhomogeneity variations up to second order from measured FIDnavs. Five volunteers were scanned at 3 T using a 64-channel coil with FID-navigated EPI. The accuracy of voxel shift measurements and geometric distortion correction was assessed for experimentally induced magnetic field perturbations. The temporal SNR was evaluated in EPI time-series acquired at rest and with a continuous nose-touching action, before and after image realignment.
Field inhomogeneity coefficients and voxel shift maps measured using FIDnavs were in excellent agreement with multi-echo EPI measurements. The FID-navigated distortion correction accurately corrected image geometry in the presence of induced magnetic field perturbations, outperforming the data-driven approach in regions with large field offsets. In functional MRI scans with nose touching, FIDnav-based correction yielded temporal SNR gains of 30% in gray matter. Following image realignment, which accounted for global image shifts, temporal SNR gains of 3% were achieved.
Our proposed application of FIDnavs enables slice-wise dynamic distortion correction with high temporal efficiency. We achieved improved signal stability by leveraging the encoding information from multichannel coils. This approach can be easily adapted to other EPI-based sequences to improve temporal SNR for a variety of clinical and research applications.
Mots-clé
Algorithms, Artifacts, Brain/diagnostic imaging, Echo-Planar Imaging, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, B0 inhomogeneity, EPI artifacts, FID navigators, dynamic distortion correction, field map, functional MRI
Pubmed
Web of science
Création de la notice
05/10/2020 15:45
Dernière modification de la notice
30/12/2023 8:07