Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-10-21
pubmed:abstractText
Electrical impedance tomography (EIT) is a recently developed technique which enables the internal conductivity of an object to be imaged using rings of external electrodes. In a recent study, EIT during cortical evoked responses showed encouraging changes in the raw impedance measurements, but reconstructed images were noisy. A simplified reconstruction algorithm was used which modelled the head as a homogeneous sphere. In the current study, the development and validation of an improved reconstruction algorithm are described in which realistic geometry and conductivity distributions have been incorporated using the finite element method. Data from computer simulations and spherical or head-shaped saline-filled tank phantoms, in which the skull was represented by a concentric shell of plaster of Paris or a real human skull, have been reconstructed into images. There were significant improvements in image quality as a result of the incorporation of accurate geometry and extracerebral layers in the reconstruction algorithm. Image quality, assessed by blinded subjective expert observers, also improved significantly when data from the previous evoked response study were reanalysed with the new algorithm. In preliminary images collected during epileptic seizures, the new algorithm generated EIT conductivity changes which were consistent with the electrographic ictal activity. Incorporation of realistic geometry and conductivity into the reconstruction algorithm significantly improves the quality of EIT images and lends encouragement to the belief that EIT may provide a low-cost, portable functional neuroimaging system in the foreseeable future.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1053-8119
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
752-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:14568449-Adult, pubmed-meshheading:14568449-Algorithms, pubmed-meshheading:14568449-Brain, pubmed-meshheading:14568449-Electric Impedance, pubmed-meshheading:14568449-Electroencephalography, pubmed-meshheading:14568449-Electromagnetic Fields, pubmed-meshheading:14568449-Epilepsy, Complex Partial, pubmed-meshheading:14568449-Finite Element Analysis, pubmed-meshheading:14568449-Humans, pubmed-meshheading:14568449-Image Processing, Computer-Assisted, pubmed-meshheading:14568449-Male, pubmed-meshheading:14568449-Models, Anatomic, pubmed-meshheading:14568449-Photic Stimulation, pubmed-meshheading:14568449-Pilot Projects, pubmed-meshheading:14568449-Psychomotor Performance, pubmed-meshheading:14568449-Seizures, pubmed-meshheading:14568449-Tomography, pubmed-meshheading:14568449-Visual Perception
pubmed:year
2003
pubmed:articleTitle
Electrical impedance tomography of human brain function using reconstruction algorithms based on the finite element method.
pubmed:affiliation
Department of Clinical Neurophysiology, University College London, UK.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, Non-U.S. Gov't