Variation in reported human head tissue electrical conductivity values

McCann, Hannah, Pisano, Giampaolo ORCID: https://orcid.org/0000-0003-4302-5681 and Beltrachini, Leandro ORCID: https://orcid.org/0000-0003-4602-1416 2019. Variation in reported human head tissue electrical conductivity values. Brain Topography 32 (5) , pp. 825-858. 10.1007/s10548-019-00710-2

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

Electromagnetic source characterisation requires accurate volume conductor models representing head geometry and the electrical conductivity field. Head tissue conductivity is often assumed from previous literature, however, despite extensive research, measurements are inconsistent. A meta-analysis of reported human head electrical conductivity values was therefore conducted to determine significant variation and subsequent influential factors. Of 3121 identified publications spanning three databases, 56 papers were included in data extraction. Conductivity values were categorised according to tissue type, and recorded alongside methodology, measurement condition, current frequency, tissue temperature, participant pathology and age. We found variation in electrical conductivity of the whole-skull, the spongiform layer of the skull, isotropic, perpendicularly- and parallelly-oriented white matter (WM) and the brain-to-skull-conductivity ratio (BSCR) could be significantly attributed to a combination of differences in methodology and demographics. This large variation should be acknowledged, and care should be taken when creating volume conductor models, ideally constructing them on an individual basis, rather than assuming them from the literature. When personalised models are unavailable, it is suggested weighted average means from the current meta-analysis are used. Assigning conductivity as: 0.41 S/m for the scalp, 0.02 S/m for the whole skull, or when better modelled as a three-layer skull 0.048 S/m for the spongiform layer, 0.007 S/m for the inner compact and 0.005 S/m for the outer compact, as well as 1.71 S/m for the CSF, 0.47 S/m for the grey matter, 0.22 S/m for WM and 50.4 for the BSCR.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Physics and Astronomy Psychology Cardiff University Brain Research Imaging Centre (CUBRIC)
Additional Information:	A correction to this article has been published and can be viewed in ORCA at http://orca.cf.ac.uk/136420
Publisher:	Springer
ISSN:	0896-0267
Date of First Compliant Deposit:	16 April 2019
Date of Acceptance:	13 April 2019
Last Modified:	06 May 2023 07:46
URI:	https://orca.cardiff.ac.uk/id/eprint/121792

Citation Data

Cited 115 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item