The temperature monitoring ability also permits post-ablation confirmation of tissue temperatures as well as temperature guided ablation of the needle track. Ultrasound is also typically used to monitor the ablation process. The current passed through the probe causes ionic agitation in the nearby tissue. This rapid vibration of the ions creates friction and therefore heat. This heat is first created immediately around the electrodes, then gradually is conducted into surrounding tissue in a predictable pattern, ultimately destroying the target area.
Heat is a very effective means of killing tissue.
The process is rapid, requiring 10-15 minutes exposure time. This is visible on ultrasound as a hyperechoic image providing additional information about the ablated area. Depending on the power applied and the electrical resistance of the tissues, heat decreases rapidly at a specific distance from the electrode tip as equilibrium is reached. The size of the ablated area is determined largely by the size of the probe, the temperature of the tissue, and the duration of time the energy is applied. There is a sharp boundary between dead tissue and unaffected surrounding tissue.