Comparison of Two Techniques for Radio-frequency Hepatic Tumor Ablation through Numerical Simulation

Abstract

We simulate the thermal and electrical processes, involved in the radio-frequency ablation procedure. In this study, we take into account the observed fact, that the electrical conductivity of the hepatic tissue varies during the procedure. With the increase of the tissue temperature to a certain level, a sudden drop of the electrical conductivity is observed. This variation was neglected in some previous studies.The mathematical model consists of two parts -electrical and thermal. The energy from the applied AC voltage is determined first, by solving the Laplace equation to find the potential distribution. After that, the electric field intensity and the current density are directly calculated. Finally, the heat transfer equation is solved to determine the temperature distribution. Heat loss due to blood perfusion is also accounted for.The simulations were performed on the IBM Blue Gene/P massively parallel computer.

Archives of Electrical Engineering

“…Next, the thermal damage of hepatic tissue for the multi-tine applicator and pre-defined limit values of electrode voltage was specified based on the Arrhenius model. Similar considerations can be found in several related papers concerning different kind of electric probes [16][17][18][19][20][21][22][23][24][25][26][27].…”

“…It was assumed that all the modelled materials are considered as isotropic, homogeneous and linear media. Because the electric field distribution within a computational area is forced by the electric potential applied on the RF electrode the Laplace equation should be employed to solve the described problem [24,25,27]:…”

Computer simulation of RF liver ablation on an MRI scan data

“…This in itself is interesting from the medical point of view. Moreover, in other computer simulations, e.g., [1,2,3,4], the position of the ground pad is neglected. Usually in those, the computational domain has a simple (cubic) shape.…”