Apparent diffusion coefficient measurements in normal appearing white matter may support the differential diagnosis between multiple sclerosis lesions and other white matter hyperintensities.

Aims: The objectives of the study were to assess the usefulness of measurements of apparent diffusion coefficient (ADC) in normal appearing white and grey matter (NAWM, NAGM) in differential diagnosis between patients with hyperintense demyelinating plaques in the course of multiple sclerosis (MS) and other conditions presenting white matter hyperintensities (WMHs), as well as to evaluate the relationship between clinical data and ADC values in MS patients.

Material And Methods: The study comprised 66 patients with MS before treatment, 66 patients with WMHs and 64 control subjects (control group, CG), who underwent MRI (magnetic resonance imaging) examination including diffusion weighted imaging (DWI) with a 1.5 T MR unit. ADC measurements were obtained from NAWM of the cerebellum, pons as well as frontal, fronto-parietal and temporal regions bilaterally, and from NAGM of thalami and heads of caudate nuclei, using round region of interest (ROI) sized 200mm.

Results: The mean ADC values in frontal, fronto-parietal and temporal NAWM were significantly higher in the MS group than in subjects with WMHs and CG (p < .001), whereas the mean ADC value in pons was higher in MS than in CG (p < .05). In the MS group we observed a positive correlation between the Expanded Disability Status Scale (EDSS) and lesion load, between duration of the disease and mean ADC values and between lesion load and mean ADC values.

Conclusion: Our results suggest that ADC measurements may support the differential diagnosis between MS and other conditions associated with white matter hyperintensities. The most significant changes were observed in temporal white matter regions.