Role of Magnetic Resonance Diffusion Tensor Imaging in Assessment of Normal Appearing White Matter in Patients with Multiple Sclerosis

Background: One non-invasive cutting-edge imaging method that can reveal details on the brain's white matter pathways' structural integrity is diffusion tensor imaging. A number of neurological and mental illnesses have made extensive use of diffusion tensor imaging metrics, such as mean diffusivity and fractional anisotropy, to assess microstructural alterations in the brain.Aim: In order to determine if diffusion tensor imaging can detect early abnormalities at the diffusion level, we will examine white matter in a patient with multiple sclerosis who appears normal on standard magnetic resonance imaging sequences.Subjects and methods: This prospective study was performed on 40 patients at the radio diagnosis department in Al-Azhar University Hospital, Cairo, Egypt, between February 2023 and February 2025. All patients were subjected to conventional magnetic resonance imaging followed by magnetic resonance diffusion tensor imaging.Results: While 32 patients (80%) exhibit normal-appearing white matter with reduced fractional anisotropy, 8 patients (20%) show normal-appearing white matter without any changes and normal fractional anisotropy. Thirteen patients (or 35% of the total) exhibit abnormally high mean diffusivity in their white matter, while twenty-six patients (or 65% of the total) show normal mean diffusivity in their white matter but no abnormalities.Conclusion: DTI quantitative parameters "Fractional anisotropy, mean diffusivity" can assess the extent of white matter hidden damage beyond the visible lesions shown by traditional MR procedures.