Simultaneous B(0)- and B(1)+-map acquisition for fast localized shim, frequency, and RF power determination in the heart at 3 T.

Détails

ID Serval
serval:BIB_24C177713CE0
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Simultaneous B(0)- and B(1)+-map acquisition for fast localized shim, frequency, and RF power determination in the heart at 3 T.
Périodique
Magnetic Resonance in Medicine
Auteur⸱e⸱s
Schär M., Vonken E.J., Stuber M.
ISSN
1522-2594[electronic], 0740-3194[linking]
Statut éditorial
Publié
Date de publication
2010
Peer-reviewed
Oui
Volume
63
Numéro
2
Pages
419-426
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural
Publication Status: ppublish
Résumé
High-field (>or=3 T) cardiac MRI is challenged by inhomogeneities of both the static magnetic field (B(0)) and the transmit radiofrequency field (B(1)+). The inhomogeneous B fields not only demand improved shimming methods but also impede the correct determination of the zero-order terms, i.e., the local resonance frequency f(0) and the radiofrequency power to generate the intended local B(1)+ field. In this work, dual echo time B(0)-map and dual flip angle B(1)+-map acquisition methods are combined to acquire multislice B(0)- and B(1)+-maps simultaneously covering the entire heart in a single breath hold of 18 heartbeats. A previously proposed excitation pulse shape dependent slice profile correction is tested and applied to reduce systematic errors of the multislice B(1)+-map. Localized higher-order shim correction values including the zero-order terms for frequency f(0) and radiofrequency power can be determined based on the acquired B(0)- and B(1)+-maps. This method has been tested in 7 healthy adult human subjects at 3 T and improved the B(0) field homogeneity (standard deviation) from 60 Hz to 35 Hz and the average B(1)+ field from 77% to 100% of the desired B(1)+ field when compared to more commonly used preparation methods.
Pubmed
Web of science
Open Access
Oui
Création de la notice
02/03/2010 15:15
Dernière modification de la notice
20/08/2019 13:03
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