Abstract: During the interventional thermal therapy of beast caner by the hepatic microwave ablation (WMA), magnetic resonance (MR) thermal imaging can obtain accurate temperature together with a reduction in the influence on the accuracy of the temperature caused by the change in the susceptibility of the WMA area. Because susceptibility is very sensitive to temperature change, a new temperature mapping correction method was proposed to reduce the influence of the temperature imaging by susceptibility change. Firstly, the temperature was calculated by the water proton resonance frequency (PRF) method. Secondly, because breast tissue contains lots of fat, the temperature was calculated by means of the water-fat separating method based on differences in the susceptibility changes between water and fat. Lastly, the temperature mapping correction method was evaluated by the temperature difference. The simulation results show that for a tissue model containing both water and fat, when the power of the WMA is 15W, the temperature mapping accuracy can reach 0.34℃ at the 300th second. All the results demonstrated the validity and feasibility of the temperature mapping correction method and its suitability for other tissues containing water and fat.

Key words: breast, microwave ablation, susceptibility correction, temperature mapping, water-fat separating