Improved Hybrid PRF-T1 Pulse Sequence for Accurate T1 Mapping in High Field (3T)

Mahamadou Diakite¹, Nick Todd², Dennis L. Parker²

Accurate temperature mapping in tumor and surrounding tissue throughout the thermal therapy is essential to ensure the safety and efficacy of thermal treatment. Methods based on the temperature dependency of the water proton resonance frequency (PRF) shift have shown the best ability to quantify temperature rises in soft tissues. Unfortunately, the PRF shift with temperature does not apply to lipid protons, since there is no hydrogen bonding among the methylene protons that supply the bulk of fat signal. However, the temperature sensitivity of the spin-lattice relaxation time, T1, has been measured for a number of fatty tissues and found to obey a linear relationship over a small temperature range [1]. We previously proposed the hybrid PRF-T1 method to combine these two techniques to simultaneously monitor temperature in fat and soft tissues. In this work, we show a sequence implementation and improve the accuracy of T1 measurements for better temperature mapping.