ABSTRACT Purpose To evaluate a three dimensional dual echo magnetic resonance fingerprinting sequence for simultaneous proton resonance frequency shift (PRFS) and thermometry during microwave ablation with improving robustness near gas bubble induced susceptibility changes while PRFS provides high precision elsewhere. Methods An ex vivo bovine liver was heated at 40 W for 8 min. A 3D stack‐of‐spiral FLASH‐MRF acquisition on a 3 T system produced simultaneous PRFS‐ and ‐based thermometry. Two fiber optic probes served as references. was calibrated to temperature using a parenchymal region in PRFS thermometry. Thermal dose was computed as CEM43 and compared with post‐cooling inversion‐recovery imaging. Results The –temperature slope was . In non‐heated parenchyma, temporal standard deviation was for PRFS and for . At probe 1, RMSE was for PRFS and for . At a susceptibility‐prone probe, PRFS RMSE was while RMSE was regarding only time points up to a CEM43 threshold of 240 min. Dose maps achieved Dice overlap of 67.13% for PRFS and 73.80% for . Conclusion A single three dimensional MRF acquisition provided complementary temperature information. PRFS delivered high precision where phase was stable. remained monotonic near susceptibility and improved dose overlap. The framework encoded and enabled in‐session calibration from PRFS.
Gutt et al. (2026) studied this question.