Preliminary static EIT images of the thorax in health and disease.

The results of a preliminary clinical evaluation of a one-frequency electrical impedance tomography (EIT) system enabling static in vivo imaging are presented. The design of the measuring system and image reconstruction software are described. Thirty-one subjects were examined and divided into four clinical groups. The first group consisted of 22 patients with clinical diagnosis of lung cancer with tumour localization in one lung. The second group consisted of seven healthy subjects. A patient after a one-sided pneumectomy and another with one-sided emphysema diagnosis were also examined. Static EIT images of a healthy human chest and a chest with various abnormalities are given and discussed. The evaluated system distinguishably visualizes various states of lungs and thorax including lung cancer. The average static conductivity of an affected lung in the first clinical group statistically differs from the average conductivity of a healthy lung. In spite of low spatial resolution, according to preliminary results, the method can be sensitive to cancer and other lung diseases in screening investigations.