Use of anisotropic modelling in electrical impedance tomography: description of method and preliminary assessment of utility in imaging brain function in the adult human head.

Détails

ID Serval
serval:BIB_F7B6CE49C4C8
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Use of anisotropic modelling in electrical impedance tomography: description of method and preliminary assessment of utility in imaging brain function in the adult human head.
Périodique
Neuroimage
Auteur(s)
Abascal J.F., Arridge S.R., Atkinson D., Horesh R., Fabrizi L., De Lucia M., Horesh L., Bayford R.H., Holder D.S.
ISSN
1095-9572[electronic], 1053-8119[linking]
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
43
Numéro
2
Pages
258-268
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
Electrical Impedance Tomography (EIT) is an imaging method which enables a volume conductivity map of a subject to be produced from multiple impedance measurements. It has the potential to become a portable non-invasive imaging technique of particular use in imaging brain function. Accurate numerical forward models may be used to improve image reconstruction but, until now, have employed an assumption of isotropic tissue conductivity. This may be expected to introduce inaccuracy, as body tissues, especially those such as white matter and the skull in head imaging, are highly anisotropic. The purpose of this study was, for the first time, to develop a method for incorporating anisotropy in a forward numerical model for EIT of the head and assess the resulting improvement in image quality in the case of linear reconstruction of one example of the human head. A realistic Finite Element Model (FEM) of an adult human head with segments for the scalp, skull, CSF, and brain was produced from a structural MRI. Anisotropy of the brain was estimated from a diffusion tensor-MRI of the same subject and anisotropy of the skull was approximated from the structural information. A method for incorporation of anisotropy in the forward model and its use in image reconstruction was produced. The improvement in reconstructed image quality was assessed in computer simulation by producing forward data, and then linear reconstruction using a sensitivity matrix approach. The mean boundary data difference between anisotropic and isotropic forward models for a reference conductivity was 50%. Use of the correct anisotropic FEM in image reconstruction, as opposed to an isotropic one, corrected an error of 24 mm in imaging a 10% conductivity decrease located in the hippocampus, improved localisation for conductivity changes deep in the brain and due to epilepsy by 4-17 mm, and, overall, led to a substantial improvement on image quality. This suggests that incorporation of anisotropy in numerical models used for image reconstruction is likely to improve EIT image quality.
Mots-clé
Algorithms, Anisotropy, Brain/physiology, Brain Mapping/methods, Computer Simulation, Electric Impedance/diagnostic use, Head/physiology, Humans, Image Interpretation, Computer-Assisted/methods, Models, Neurological, Phantoms, Imaging, Pilot Projects, Plethysmography, Impedance, Tomography
Pubmed
Web of science
Création de la notice
25/02/2011 12:15
Dernière modification de la notice
03/03/2018 22:50
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