Tissue Impedance Implications of Performing RF Ablation at 64 MHz

Kim Shultz¹, Pascal Stang¹, John Pauly¹, Greig Scott¹

If RF ablation is performed at 64 MHz instead of 500 kHz, the RF magnetic field generated by the ablation current can be imaged with B1 mapping techniques. Changing the frequency of the ablation changes the impedance response of the tissue to heating, with potential implications for the ablation process. We compared the impedance response of RF ablation at both frequencies, using MRI to obtain temperature and B1 maps of the 64 MHz ablation. The 64 MHz ablation undergoes a more limited impedance roll-off at high temperatures, potentially allowing higher temperatures while still effectively ablating.