title: Impedance imaging in upper arm fractures.
abstract: We used the Aberdeen impedance imaging system to drive a constant current of 1 mA on a 10 kHz sine wave into the upper arm encircled by an elastic belt of 16 equi-spaced strip electrodes. The system was used to examine a normal upper arm, an upper arm with a recent humeral fracture and an upper arm with a clinically united fracture. We approximated the human upper arm to a circular cylinder and assumed bilateral symmetry of normal human limbs. We measured transverse limb resistivity ratios and reconstructed static two-dimensional images of the spatial distribution of log(resistivity) by the equipotential back projection technique using a homogeneous muscle equivalent saline reference. Our results indicate that impedance osteography provides unique information about the changing electrical characteristics at the fracture site. This information could prove a useful adjunct to clinical and radiological tests for fracture union.
authors.affiliation: Department of Biomedical Physics and BioEngineering, University of Aberdeen, Forresterhill, Scotland.
authors.forename: V
authors.initials: V
authors.lastname: Kulkarni
authors.forename: J M
authors.initials: JM
authors.lastname: Hutchison
authors.forename: I K
authors.initials: IK
authors.lastname: Ritchie
authors.forename: J R
authors.initials: JR
authors.lastname: Mallard
mesh_terms: D002138:Calibration; D003952:Diagnostic Imaging / Q000379:methods*; D004553:Electric Conductivity; D004566:Electrodes; D006801:Humans; D006810:Humeral Fractures / Q000175:diagnosis*; D006811:Humerus / Q000033:anatomy & histology; D012016:Reference Values