Optimization and application of MP2RAGE sequence for T1-based thermometry in the fat layer of the human calve

Motivation: MR Thermometry is highly valuable for RF safety research. However, the most common method (PRFS) cannot measure temperature in fat. Goal(s): Establish a method for T1-based thermometry in fat with high sensitivity to measure sub-degree temperature rise. Approach: Utilize the MP2RAGE sequence to measure temperature-induced T1 changes and optimize imaging parameters through Bloch simulations. Test the method with phantom experiments and in-vivo measurements. Results: The proposed T1-based thermometry method demonstrates sufficient sensitivity to measure RF-induced temperature rise in muscle and fatty tissues while abiding SAR limits of regular MRI sequences. Impact: We present a highly sensitive T1-based thermometry method applicable in fatty tissues for RF safety research. MRT in fat will be valuable to improve verification by fiber-optic probes on the skin and -using intrinsic reference- assessment of fat susceptibility change.