Electrical impedance characterization of normal and cancerous human hepatic tissue

The four-electrode method was used to measure the ex-vivo complex electrical impedance of tissues from14 hepatic tumors and the surrounding normal liver from 6 patients. Measurements were done in the frequency range of 1 kHz - 400 kHz. It was found that the conductivity of the tumor tissue was much higher than that of the normal liver tissue in this frequency range (from 0.14 ±0.06 S m−1 vs. 0.03 ±0.01 S m−1 at 1 kHz to 0.25 ±0.06 S m−1 vs. 0.15 ±0.03 S m−1 at 400 kHz). Cole-Cole models were estimated from the experimental data and the four parameters (ρ0,ρ∞,α,fc) were obtained using a least squares fit algorithm. The Cole-Cole parameters for cancerous and normal liver are (9 ±4 Ω m−1,2.2±0.7 Ω m−1,0.5±0.2,140±103 kHz) and (50±28 Ω m−1,3.2 ±0.6 Ω m−1,0.64±0.04,10±7 kHz), respectively. These data can contribute to developing bioelectric applications for tissue diagnostics, and in tissue treatment planning with electrical fields such as radiofrequency tissue ablation, electrochemotherapy and gene therapy with reversible electroporation, nanoscale pulsing and irreversible electroporation