Probing white matter microstructure in multiple sclerosis patients using standard model diffusion MRI

Motivation: The Standard Model Imaging (SMI) technique, based on diffusion magnetic resonance imaging (MRI), introduces a novel approach for detecting microstructural features of white matter (WM). Goal(s): This study aims to implement SMI to characterize WM injury in people with MS (PwMS) brains and investigate its clinical feasibility Approach: Four different types of brain tissues in PwMS were manually outlined, representing different levels of tissue injury. The SMI-derived microstructural metrics were compared among different tissue types. Results: SMI-derived axonal fraction f and extra-axonal perpendicular $Dₑ^⊥$ not only distinguish MS lesions from normal appearing WM (NAWM) but also differentiate MS lesions with different severity. Impact: SMI-derived metrics are sensitive to pathological changes in MS lesions and show promise for clinical applications in MS.