Differentiating multiple sclerosis from other causes of demyelination using diffusion weighted imaging of the corpus callosum

Purpose: To compare diffusion weighted imaging metrics in gray and white matter brain regions of patients diagnosed with multiple sclerosis (MS) to those diagnosed with secondary demyelinating diseases such as neurosarcoid and acute disseminated encephalomyelitis (ADEM). Materials and Methods: Diffusion weighted scans were performed and apparent diffusion coefficients of 12 regions of interest were determined in 30 MS patients, 21 neurosarcoid patients, and 4 ADEM patients. Results: Mean apparent diffusion coefficients were significantly higher in MS patients than in non-MS patients in 6 of 6 of the corpus callosal regions assessed but not in any of the non-callosal white or gray matter regions assessed. Conclusion: Elevated apparent diffusion coefficients within the corpus callosum on diffusion weighted imaging may potentially help differentiate between patients with MS and patients with other diseases affecting the central nervous system white matter.