Assessment of Real-Time PRFS Thermometry Feasibility and Accuracy at 0.55 T for Interventional Ablation Procedures and MRI Safety

Motivation: Evaluate the feasibility of proton resonance frequency shift (PRFS) thermometry at 0.55T while assessing achievable accuracy and its potential use in interventional MRI ablation procedures and safety evaluations. Goal(s): Determine the performance of PRFS thermometry at 0.55T against calibrated fiber-optic temperature probes. Approach: Perform phase-shift, drift-corrected thermometry on a homogeneous agar/copper sulfate phantom during heating and cooling with simultaneous temperature probe measurements. Results: Temperature change was measured for up to one hour with drift correction, and measurements correlated well with the fiber-optic probes. The mean difference between measurements was 0.93±0.35°C and average limit of agreement window (±1.96 SD) was 3.86°C. Impact: This study explored the accuracy of thermometry at 0.55T in simple homogenous phantoms while looking ahead to implementation in iMRI applications. Thermometry at 0.55T has potential for real-time temperature monitoring with a clinically relevant degree of accuracy.