The study showed that the normal appearing white matter is pathologically involved in the majority of our patients (84%) and the degree and distribution of involvement has direct relation to some morphologic features (brain atrophy and T2 burden of the disease) that reflect the disease severity and duration. The study showed that the NAWM changes are not directly related to the largest plaques or to the regions of black holes formation on T1 WIs. The aim of our study was to evaluate the role of DTI in the assessment of normal appearing white matter in patients with multiple sclerosis. Changes in the NAWM were examined and their relation to other morphologic MR features was evaluated.