Background/Objectives: Microwave ablation (MWA) is the leading therapy method for treating patients with liver cancer. MWA simulation is used to further improve the therapy and to help develop new devices. Methods: A water-cooled ablation needle was reconstructed. MWA simulations of a polyacrylamide phantom were carried out and compared with a representative clinical example (tumor diameter: 8.75 mm). The Arrhenius damage model and a critical temperature approach of 60 °C were applied to assess the necrosis zones. Finally, the simulation results were compared to the corresponding MR measurements. Results: Most of the heating in the simulation took place at a distance of 5 mm along the transverse axis and 20 mm along the longitudinal axis above the needle tip. The calculated Dice scores for the Arrhenius model were 0.77/0.53 for the phantom/clinical case. For the critical temperature approach, Dice scores of 0.60/0.66 for the phantom/clinical case were achieved. Conclusions: The comparison between simulated and measured temperature increases showed an excellent agreement. However, differences in the predicted necrosis volume might be caused by omitting consideration of the heat sink effect, especially in the clinical case. Nevertheless, this workflow enables short MWA simulation times (approximately 3 min) and demonstrates a step towards possible integration into daily clinical use.

Microwave ablation (MWA) of hepatic tumors benefits from MR thermometry, enabling real-time temperature monitoring to guide treatment and protect healthy tissue. However, MR thermometry in the abdomen is challenging due to respiratory and intestinal motion. This study evaluates two advanced 3D imaging sequences, Stack-of-Stars (Stars) and Stack-of-Spirals (Spirals), for precise MWA thermometry in phantom and volunteer experiments. Spirals demonstrated superior temperature precision, with a standard deviation of 0.78 ± 0.05°C in unheated regions, compared to 2.92 ± 0.26°C for Stars. In heated regions, Spirals achieved a lower RMSE (0.5 ± 0.1°C vs. 1.2 ± 0.2°C for Stars) and a higher Dice score for ablation zone delineation (0.89 ± 0.01 vs. 0.76 ± 0.10). Spirals also produced sharper images with fewer artifacts under simulated respiratory motion, while Stars showed streaking artifacts due to higher undersampling. These findings highlight Spirals’ potential for accurate real-time thermometry in liver ablation. Future work should focus on improving reconstruction speed and mitigating susceptibility artifacts to enable clinical applications.