Unified segmentation based correction of R1 brain maps for RF transmit field inhomogeneities (UNICORT).

Détails

ID Serval
serval:BIB_7806676F7985
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Unified segmentation based correction of R1 brain maps for RF transmit field inhomogeneities (UNICORT).
Périodique
Neuroimage
Auteur(s)
Weiskopf N., Lutti A., Helms G., Novak M., Ashburner J., Hutton C.
ISSN
1095-9572 (Electronic)
ISSN-L
1053-8119
Statut éditorial
Publié
Date de publication
02/2011
Volume
54
Numéro
3
Pages
2116-2124
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Résumé
Quantitative mapping of the longitudinal relaxation rate (R1=1/T1) in the human brain enables the investigation of tissue microstructure and macroscopic morphology which are becoming increasingly important for clinical and neuroimaging applications. R1 maps are now commonly estimated from two fast high-resolution 3D FLASH acquisitions with variable excitation flip angles, because this approach is fast and does not rely on special acquisition techniques. However, these R1 maps need to be corrected for bias due to RF transmit field (B1(+)) inhomogeneities, requiring additional B1(+) mapping which is usually time consuming and difficult to implement. We propose a technique that simultaneously estimates the B1(+) inhomogeneities and R1 values from the uncorrected R1 maps in the human brain without need for B1(+) mapping. It employs a probabilistic framework for unified segmentation based correction of R1 maps for B1(+) inhomogeneities (UNICORT). The framework incorporates a physically informed generative model of smooth B1(+) inhomogeneities and their multiplicative effect on R1 estimates. Extensive cross-validation with the established standard using measured B1(+) maps shows that UNICORT yields accurate B1(+) and R1 maps with a mean deviation from the standard of less than 4.3% and 5%, respectively. The results of different groups of subjects with a wide age range and different levels of atypical brain anatomy further suggest that the method is robust and generalizes well to wider populations. UNICORT is easy to apply, as it is computationally efficient and its basic framework is implemented as part of the tissue segmentation in SPM8.
Mots-clé
Adult, Aging/physiology, Algorithms, Brain/growth & development, Brain/radiography, Brain Mapping/methods, Cerebrospinal Fluid/physiology, Data Interpretation, Statistical, Female, Humans, Image Processing, Computer-Assisted, Male, Middle Aged, Models, Neurological, Models, Statistical, Normal Distribution, Phantoms, Imaging, Radio Waves, Reproducibility of Results, Young Adult
Pubmed
Web of science
Open Access
Oui
Création de la notice
08/07/2013 10:22
Dernière modification de la notice
08/05/2019 20:38
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