Diffusion MRI for the detection of hippocampal abnormalities in temporal lobe epilepsy

Motivation: Surgical outcomes for patients with temporal lobe epilepsy (TLE) are limited by the lack of imaging biomarkers that are sensitive to abnormalities. Goal(s): Our goal was to assess the sensitivity of diffusion MRI metrics to hippocampal abnormalities in patients with TLE. Approach: We measured mean diffusivity and microscopic fractional anisotropy in a specific hippocampal subfield in TLE patients and healthy volunteers, then used logistic regression to classify cohorts. Results: The diffusion model was better at distinguishing between patients and volunteers than typical measurements of hippocampal volume, assessed using receiver operating characteristic curves (area under curve 0.87 vs. 0.71-0.76). Impact: Advanced diffusion MRI metrics are sensitive to hippocampal abnormalities in temporal lobe epilepsy and may be able to improve surgical outcomes by helping clinicians locate the seizure focus for surgical excision.