Different methods of modelling temperature dependence of thermal and electrical conductivities resulted in maximum relative differences in short lesion diameter below 3.5% after 6 minutes of ablation.
Do different mathematical functions for modeling temperature dependence of thermal and electrical conductivities significantly affect computed lesion dimensions and impedance evolution in RFA computational models?
Different methods of modeling temperature dependence of thermal and electrical conductivities in RFA computational models do not significantly affect the computed lesion diameter.
PURPOSE: Although theoretical modelling is widely used to study different aspects of radiofrequency ablation (RFA), its utility is directly related to its realism. An important factor in this realism is the use of mathematical functions to model the temperature dependence of thermal (k) and electrical (σ) conductivities of tissue. Our aim was to review the piecewise mathematical functions most commonly used for modelling the temperature dependence of k and σ in RFA computational modelling. MATERIALS AND METHODS: We built a hepatic RFA theoretical model of a cooled electrode and compared lesion dimensions and impedance evolution with combinations of mathematical functions proposed in previous studies. We employed the thermal damage contour D63 to compute the lesion dimension contour, which corresponds to Ω = 1, Ω being local thermal damage assessed by the Arrhenius damage model. RESULTS: The results were very similar in all cases in terms of impedance evolution and lesion size after 6 min of ablation. Although the relative differences between cases in terms of time to first roll-off (abrupt increase in impedance) were as much as 12%, the maximum relative differences in terms of the short lesion (transverse) diameter were below 3.5%. CONCLUSIONS: The findings suggest that the different methods of modelling temperature dependence of k and σ reported in the literature do not significantly affect the computed lesion diameter.
Trujillo et al. (Wed,) conducted a review in Hepatic radiofrequency ablation (computational model). Mathematical functions to model temperature dependence of thermal and electrical conductivities vs. Alternative combinations of mathematical functions was evaluated on Lesion dimensions and impedance evolution. Different methods of modelling temperature dependence of thermal and electrical conductivities resulted in maximum relative differences in short lesion diameter below 3.5% after 6 minutes of ablation.