Monitoring microwave thermal ablation using electrical impedance tomography: An experimental feasibility study

Low-cost and reliable methods for monitoring the size of the ablation zone during microwave thermal ablation (MTA) are crucial in the oncological clinical practice. The aim of this work is to test the performance of electrical impedance tomography (EIT) for the real-time monitoring of the ablation area where relevant temperature increases occur. In this work, two experimental studies were performed with a 16-electrode EIT system using a liver-mimicking agar phantom. First, an EIT system was tested to monitor the cooling of the phantom from an initial temperature of about 72°C. Secondly, the heating and the consequent cooling of the phantom were monitored. The heating was performed using the MTA applicator operating at 30W for 10 minutes at 2.45GHz. The results reporting the voltage and temperature data acquired, as well as the reconstructed time series images, confirm the feasibility of EIT to monitor the changes of the electrical conductivity with temperature.