Assessment of Transcapillary Water Exchange in the Lungs by Active Radiometry

Abstract

The possibility of noninvasive assessment of transcapillary water exchange in the lungs using stimulated microwave emission of the chest organs is discussed. The results of the study showed that the distribution of 1 GHz microwave emission of tissues probed using low-intensity electromagnetic waves at 65 GHz corresponded to the distribution of pulmonary blood flow. Calculations showed that the intensity of transcapillary water exchange in the lungs was distributed exponentially from the apices to the basal parts of the lungs. The distribution of the transcapillary water exchange was shown to vary according to the pulmonary perfusion gradient, which is indicative of a correlation between the parameters of pulmonary perfusion and the intensity of stimulated microwave emission of tissues at the frequency of 1 GHz. This correlation can be used for noninvasive assessment of pulmonary perfusion by active radiometry.