Temperature-Range-Dependent Optimization of Noninvasive MR Thermometry Methods

Noninvasive temperature monitoring is feasible with Magnetic Resonance Imaging (MRI) based on temperature sensitive MR parameters such as and relaxation times, Proton Resonance Frequency shift (PRFs), diffusion, exchange process, magnetization transfer contrast, chemical exchange saturation transfer, etc. While the temperature monitoring is very useful to guide the thermal treatment such as RF hyperthermia or thermal ablation, the optimization of the MR thermometry method is essential because the range of temperature measurement depends on the choice of the measurement methods. Useful temperature range depends on the purpose of treatment methods, for example, to for RF hyperthermia and over for thermal ablation. In this paper, MR thermometry methods using and relaxation times and PRFs-based MR thermometry are tried on a 3.0 T MRI system and their results are reported and compared. In addition, the scanning protocol and temperature calculation algorithms from and relaxation times and PRFs are optimized for the different temperature ranges for the purpose of RF hyperthermia and/or thermal ablation.