Assessment of RF induced tissue heating at 3T through MR Thermometry with comparison to subject-specific simulations

Motivation: The exact amount of RF-induced temperature rise in MRI is unknown. Goal(s): Assess RF-induced temperature elevation at 3T using MRT and compare these to simulations. Approach: We use a method based on PRFS to measure temperature around the knee in four subjects at 3T. Here, multi-echo data is fit to a signal model to separate temperature rise from field drifts. Measured temperature rise distributions are subsequently compared to probe measurements and subject-specific simulations. Results: Heating scans show temperature rises up to 1.9 °C. Hotspot location and spatial distributions between measurements and subject-specific simulations are in agreement, but simulations always tend to underestimate measurements. Impact: Within RF safety SAR guidelines, MRT measurements of RF induced heating for 3T MRI are feasible around the knees and show temperature increases of almost 2 °C. Among others, the presented methodology provides promise for potential validation of thermal simulations.