Fast calculation or simulation of the ablation zone induced by radiofrequency ablation (RFA) has a critical role in hepatic RFA planning and therapy. However, it remains challenging to approximate the ablation zone in real time, especially when more than one probe is involved in one ablation session. This paper presents a novel computational technique to calculate the 3D ablation zone of one probe RFA and two-probe switching RFA. The main idea is to get an approximate solution of the temperature distribution from a simplified Pennes bioheat equation, and further fit the solution to the coagulation measurements on ex vivo porcine liver. With a closed-form solution of temperature distribution, the calculation of the ablation zone is as simple as the commonly used ellipsoidal model, but it allows a more realistic prediction of combined ablation zones with different inter-probe spacing. The new approximation technique could potentially replace the original ellipsoidal model in the intervention planning step.

射频消融 (RFA) 引起的消融区的快速计算或模拟在肝脏 RFA 规划和治疗中具有关键作用。然而，实时近似消融区域仍然具有挑战性，尤其是当一个消融会话中涉及多个探头时。本文提出了一种新的计算技术来计算单探针 RFA 和双探针切换 RFA 的 3D 消融区。主要思想是从简化的 Pennes 生物热方程中获得温度分布的近似解，并进一步将该解与体外凝血测量结果拟合猪肝。使用温度分布的封闭形式解，消融区的计算与常用的椭球模型一样简单，但它可以更真实地预测具有不同探针间距的组合消融区。新的近似技术可能会在干预计划步骤中取代原始的椭球模型。