Imaging of pulmonary edema with electrical impedance tomography

Electrical impedance tomography (EIT) uses electrical measurements at electrodes placed on the thorax to image changes in the conductivity distribution within the thorax. This technique should be of interest in studying pulmonary edema as the clinical phenomena of interest induce large conductivity changes. The authors have conducted a series of experiments on dogs to quantify the capacity of EIT to measure lung tidal volume and fluid content. Results indicate good correlation of the quantities measured by EIT with standard reference techniques. Certain difficulties with the long term stability of electrodes and measurement electronics were noted as design criteria for future EIT systems.