title: The effect of the skull of low-birthweight neonates on applied potential tomography imaging of centralised resistivity changes.
abstract: An investigation is presented into the likely effects of the neonatal skull on impedance images produced by applied potential tomography (APT) by imaging impedance changes inside the skull of a human infant of occipito-frontal circumference 30 cm. Measurements have been made with the skull immersed in a tank of saline and electrodes fixed to the perimeter of the tank. Sensitivity measurements have been assessed for imaging a small target close to the centre of the skull as compared with images produced without the skull. The results obtained compare favourably with measurements on a more realistic model of the neonatal head constructed by filling the skull with agar jelly to leave only a thin exterior coating of jelly to simulate the scalp. These experiments suggest that in the central region of the head of a neonate, measured changes by the APT technique are about 44% of that expected from a homogeneous phantom, but that this might vary from 32% to 55% at different points in the image in a very complex manner.
authors.affiliation: Sheffield University, Department of Medical Physics and Clinical Engineering, Royal Hallamshire Hospital, UK.
authors.forename: F J
authors.initials: FJ
authors.lastname: McArdle
authors.forename: B H
authors.initials: BH
authors.lastname: Brown
authors.forename: R G
authors.initials: RG
authors.lastname: Pearse
authors.forename: D C
authors.initials: DC
authors.lastname: Barber
mesh_terms: D001921:Brain / Q000502:physiology*; D004553:Electric Conductivity; D005333:Fetus; D006801:Humans; D007230:Infant, Low Birth Weight / Q000502:physiology*; D007231:Infant, Newborn; D012886:Skull / Q000033:anatomy & histology*; D014054:Tomography / Q000379:methods*