Evaluating fast R2-mapping approaches for application in temporal lobe epilepsy: a traveling head study

Motivation: Drug-resistant temporal lobe epilepsy (DTLE) requires localizing subtle abnormalities for effective surgery. Transverse relaxation rate (R2) mapping can help reveal these abnormalities but is time-intensive. Goal(s): Evaluating two fast R2 mapping approaches for DTLE: magnitude-phase-based relaxation (MPR) and controlled saturation magnetization transfer with joint system relaxation (CSMT-JSR). Approach: We tested MPR and CSMT-JSR on the same set of subjects at the development and intended application sites. We assessed R2 variability across gray matter regions, subjects, and scan-rescan. Results: MPR showed higher inter-region differences and lower scan-rescan variability, suggesting greater potential to capture anatomical variation, while being twice as fast. Impact: We identify a fast R2 mapping method with reliable sensitivity to key regions in drug-resistant temporal lobe epilepsy. Our findings could expand R2 mapping accessibility for clinical application and contribute to improved surgical planning.