Computing myelin and axonal volume fractions in gray and white matters and g-ratio map using multiple-inversion MRF and NODDI

Motivation: Multiple sclerosis effect both white matter and gray matter. Goal(s): Using mIR-MRF with NODDI to generate myelin water fraction map, g-ratio map, and axonal volume fraction gray matter map. Approach: White matter, gray matter, cerebrospinal fluid (CSF), and myelin water fraction (MWF) map were generated by mIR MRF. NODDI was used to divide each voxel into isotropic (Viso) and anisotropically restricted volume fraction (Vic) map. These maps were used to generate the g-ratio and AVF-gm map. Results: The WM lesions were in consistency within FLAIR and MWF but have a variance in g-ratio maps. AVF-gm map depicted the axonal fiber in GM well. Impact: The mIR MRF with NODDI could provide insight of demyelination, axonal loss and the change in GM of MS.