Accurate in vivo dielectric properties of liver from 500 MHz to 40 GHz and their correlation to ex vivo measurements

Abstract

In this article, we report on the characterization of the dielectric properties of in vivo rat liver at 36.4°C from 500 MHz up to 40 GHz with less than 5% uncertainty. The measured data were fitted to a Cole–Cole model and dielectric parameters are presented together with their respective 95% confidence interval. The root mean square error is 0.42. Moreover, ex vivo measurements were conducted in situ at 1, 2, 4 and 6 min after animal death and are compared to in vivo measurements. The results show that immediate changes in and are within experimental uncertainty, and therefore changes between in vivo and published ex vivo dielectric properties can be attributed to tissue hydration.