Real-time shimming with FID navigators.

Details

Serval ID
serval:BIB_8288A856B22A
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Real-time shimming with FID navigators.
Journal
Magnetic resonance in medicine
Author(s)
Wallace T.E., Kober T., Stockmann J.P., Polimeni J.R., Warfield S.K., Afacan O.
ISSN
1522-2594 (Electronic)
ISSN-L
0740-3194
Publication state
Published
Issued date
12/2022
Peer-reviewed
Oui
Volume
88
Number
6
Pages
2548-2563
Language
english
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
To implement a method for real-time field control using rapid FID navigator (FIDnav) measurements and evaluate the efficacy of the proposed approach for mitigating dynamic field perturbations and improving -weighted image quality.
FIDnavs were embedded in a gradient echo sequence and a subject-specific linear calibration model was generated on the scanner to facilitate rapid shim updates in response to measured FIDnav signals. To confirm the accuracy of FID-navigated field updates, phantom and volunteer scans were performed with online updates of the scanner B <sub>0</sub> shim settings. To evaluate improvement in -weighted image quality with real-time shimming, 10 volunteers were scanned at 3T while performing deep-breathing and nose-touching tasks designed to modulate the B <sub>0</sub> field. Quantitative image quality metrics were compared with and without FID-navigated field control. An additional volunteer was scanned at 7T to evaluate performance at ultra-high field.
Applying measured FIDnav shim updates successfully compensated for applied global and linear field offsets in phantoms and across all volunteers. FID-navigated real-time shimming led to a substantial reduction in field fluctuations and a consequent improvement in -weighted image quality in volunteers performing deep-breathing and nose-touching tasks, with 7.57% ± 6.01% and 8.21% ± 10.90% improvement in peak SNR and structural similarity, respectively.
FIDnavs facilitate rapid measurement and application of field coefficients for slice-wise B <sub>0</sub> shimming. The proposed approach can successfully counteract spatiotemporal field perturbations and substantially improves -weighted image quality, which is important for a variety of clinical and research applications, particularly at ultra-high field.
Keywords
Brain/diagnostic imaging, Calibration, Humans, Image Processing, Computer-Assisted/methods, Linear Models, Magnetic Resonance Imaging/methods, Phantoms, Imaging, , -weighted imaging, B0 inhomogeneity, FID navigators, artifact correction, real-time shimming
Pubmed
Web of science
Create date
20/09/2022 12:47
Last modification date
22/09/2023 6:56
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