On the origin of the MR image phase contrast: an in vivo MR microscopy study of the rat brain at 14.1 T.

Détails

ID Serval
serval:BIB_6650494170CF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
On the origin of the MR image phase contrast: an in vivo MR microscopy study of the rat brain at 14.1 T.
Périodique
Neuroimage
Auteur⸱e⸱s
Marques J.P., Maddage R., Mlynarik V., Gruetter R.
ISSN
1095-9572 (Electronic)
ISSN-L
1053-8119
Statut éditorial
Publié
Date de publication
2009
Volume
46
Numéro
2
Pages
345-352
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Résumé
Recent studies at high magnetic fields using the phase of gradient-echo MR images have shown the ability to unveil cortical substructure in the human brain. To investigate the contrast mechanisms in phase imaging, this study extends, for the first time, phase imaging to the rodent brain. Using a 14.1 T horizontal bore animal MRI scanner for in vivo micro-imaging, images with an in-plane resolution of 33 microm were acquired. Phase images revealed, often more clearly than the corresponding magnitude images, hippocampal fields, cortical layers (e.g. layer 4), cerebellar layers (molecular and granule cell layers) and small white matter structures present in the striatum and septal nucleus. The contrast of the phase images depended in part on the orientation of anatomical structures relative to the magnetic field, consistent with bulk susceptibility variations between tissues. This was found not only for vessels, but also for white matter structures, such as the anterior commissure, and cortical layers in the cerebellum. Such susceptibility changes could result from variable blood volume. However, when the deoxyhemoglobin content was reduced by increasing cerebral blood flow (CBF) with a carbogen breathing challenge, contrast between white and gray matter and cortical layers was not affected, suggesting that tissue cerebral blood volume (and therefore deoxyhemoglobin) is not a major source of the tissue phase contrast. We conclude that phase variations in gradient-echo images are likely due to susceptibility shifts of non-vascular origin.
Mots-clé
Animals, Brain/cytology, Image Enhancement/methods, Magnetic Resonance Imaging/methods, Magnetic Resonance Imaging/veterinary, Microscopy, Phase-Contrast/methods, Microscopy, Phase-Contrast/veterinary, Rats, Rats, Sprague-Dawley, Reproducibility of Results, Sensitivity and Specificity
Pubmed
Web of science
Création de la notice
04/08/2010 16:28
Dernière modification de la notice
20/08/2019 15:22
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