Feasibility Study of Subject-Specific Brain SAR Maps Retrieved from MRI Data

Motivation: SAR monitoring and assessment rely on simulations, which are impractical for real-time clinical use due to high computational demands. Goal(s): To validate a method for obtaining subject-specific SAR maps from standard MRI sequences. Approach: SAR maps were generated from the complex B1+ field derived from B1 magnitude (XFL) and phase of a bSSFP sequence. Tissue conductivity was estimated using a phase-based Helmholtz electrical properties tomography (EPT) approach, and the electric field was calculated with Ampère's law. Results: SAR maps that align with simulation results were produced in 12 minutes, an advancement toward real-time SAR measurement (r=0.52). Impact: A method for image-based patient-specific SAR mapping retrieved from acquired MRI data in the brain is demonstrated. The resulting maps aligned with electromagnetic simulation-based SAR maps, representing a step toward practical SAR monitoring during clinical examinations.