An MRF approach for Simultaneous T1- and PRFS-based 3D MR-Thermometry

Motivation: The classical PRFS-based approach to MR-thermometry cannot be used in adipose tissue and is vulnerable to susceptibility artifacts. Nonetheless, the PRFS-based method is quite accurate in aqueous tissue when no severe susceptibility artifacts occur. Goal(s): A simultaneous measurement of T1 could be used to account for susceptibility artifacts and perform thermometry in adipose tissue. Approach: An MRF sequence was designed to measure T1 and the PRF at the same time. It was tested during a microwave ablation on a liver phantom. Results: The PRFS-based temperature maps had a higher temperature accuracy while the T1-based temperature maps performed better in predicting the ablation zone. Impact: It was shown that simultaneous T1- and PRFS-based 3D-Thermometry is possible using MRF. While the T1 proved to be more robust to susceptibility-induced errors, the PRF had a better temperature accuracy. A combined approach could provide a more accurate MR-thermometry.