Changes in the Dielectric Properties of ex-vivo Ovine Kidney Before and After Microwave Thermal Ablation

In this work, a comparison in terms of dielectric properties (i.e. relative permittivity and conductivity) between ablated and non-ablated kidney samples (N = 3) was conducted. Measurements before and after ablation (N = 54) were performed on three different tissues (cortex, outer medulla, inner medulla) of ex-vivo ovine kidneys across the frequency range of 500 MHz - 8.5 GHz. Results show that both relative permittivity and conductivity decrease after ablation because of the decrease of the water content in the tissue. In particular, the highest difference between pre-ablation and post-ablation was observed in the tissue characterised by the highest water content.