Capturing microstructure anisotropy changes in normal-appearing white matter

Takeaway

  • Microfractional anisotropy (μFA) correlates with global lesion load, physical disability (Expanded Disability Status Scale [EDSS]) and cognitive function (Symbol Digit Modality Test [SDMT]) in patients with multiple sclerosis (MS).

Why this matters

  • Lesions in MS can give rise to widespread changes in the surrounding normal-appearing white matter (NAWM), such as axonal degeneration and demyelination. However, these are poorly visualized and quantified by standard magnetic resonance imaging (MRI) techniques. The combination of conventional diffusion tensor imaging MRI with spherical tensor encoding allows the estimation of a μFA map, allowing the resolution of microstructural tissue features.

  • This study demonstrated that μFA correlates with lesion load, EDSS and SDMT, providing a tool for monitoring disease progression and testing the efficacy of new treatments.