Rapid measurement and correction of spatiotemporal B<sub>0</sub> field changes using FID navigators and a multi-channel reference image.

Détails

ID Serval
serval:BIB_E6777C170604
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Rapid measurement and correction of spatiotemporal B<sub>0</sub> field changes using FID navigators and a multi-channel reference image.
Périodique
Magnetic resonance in medicine
Auteur⸱e⸱s
Wallace T.E., Afacan O., Kober T., Warfield S.K.
ISSN
1522-2594 (Electronic)
ISSN-L
0740-3194
Statut éditorial
Publié
Date de publication
02/2020
Peer-reviewed
Oui
Volume
83
Numéro
2
Pages
575-589
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
To measure spatiotemporal B <sub>0</sub> field changes in real time using FID navigators (FIDnavs) and to demonstrate the efficacy of retrospectively correcting high-resolution -weighted images using a novel FIDnav framework.
A forward model of the complex FIDnav signals was generated by simulating the effect of changes in the underlying B <sub>0</sub> inhomogeneity coefficients, with spatial encoding provided by a multi-channel reference image. Experiments were performed at 3T to assess the accuracy of B <sub>0</sub> field estimates from FIDnavs acquired from a 64-channel head coil under different shim settings and in 5 volunteers performing deep-breathing and nose-touching tasks designed to modulate the B <sub>0</sub> field. Second-order, in-plane spherical harmonic (SH) inhomogeneity coefficients estimated from FIDnavs were incorporated into an iterative reconstruction to retrospectively correct 2D gradient-echo images acquired in both axial and sagittal planes.
Spatiotemporal B <sub>0</sub> field changes measured from rapidly acquired FIDnavs were in good agreement with the results of second-order SH fitting to the measured field maps. FIDnav field estimates accounted for a significant proportion of the ΔB <sub>0</sub> variance induced by deep breathing (64 ± 21%) and nose touching (67 ± 34%) across all volunteers. Ghosting, blurring, and intensity modulation artifacts in -weighted images, induced by spatiotemporal field changes, were visibly reduced following retrospective correction with FIDnav inhomogeneity coefficients.
Spatially resolved B <sub>0</sub> inhomogeneity changes up to second order can be characterized in real time using the proposed approach. Retrospective FIDnav correction substantially improves -weighted image quality in the presence of strong B <sub>0</sub> field modulations, with potential for real-time shimming.
Mots-clé
Adult, Algorithms, Arm/physiology, Artifacts, Brain/diagnostic imaging, Brain Mapping/methods, Echo-Planar Imaging/methods, Female, Head, Humans, Image Processing, Computer-Assisted/methods, Imaging, Three-Dimensional, Magnetic Resonance Imaging/methods, Male, Models, Statistical, Motion, Respiration, Retrospective Studies, Signal Processing, Computer-Assisted, B0 inhomogeneity, FID navigators, retrospective artifact correction, spatiotemporal field changes
Pubmed
Web of science
Open Access
Oui
Création de la notice
17/09/2019 16:34
Dernière modification de la notice
17/02/2024 8:12
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