ELECTRICAL-IMPEDANCE TOMOGRAPHY

Electrical impedance tomography (EIT) is a technique which allows cros s-sectional images related to the local electrical impedance within an object to be reconstructed from sets of measurements made on its surf ace. The main drive behind the development of EIT has been its possibl e application in medical imaging, as biological tissues are known to e xhibit a wide range of electrical impedance and many physiological eve nts are accompanied by electrical impedance changes. This article revi ews the technical aspects of EIT as a medical imaging modality, and co nsiders the range of applications over which it might be employed. Exi sting technical limitations and future developments are discussed. It is concluded that the future of EIT as a clinical diagnostic tool is l ikely to lie in the area of functional monitoring, where the capabilit y of performing image-guided localized electrical impedance measuremen ts with high acquisition speed, good sensitivity and no hazard can be exploited.