Diffusional kurtosis imaging of normal-appearing white matter in multiple sclerosis: preliminary clinical experience

Purpose We evaluated diffusional changes in normal-appearing white matter (NAWM) regions remote from multiple sclerosis (MS) plaques by using diffusional kurtosis imaging (DKI) to investigate the non-Gaussian behavior of water diffusion. Materials and methods Participants were 11 MS patients and 6 age-matched healthy volunteers. DKI was performed on a 3-T MR imager. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and diffusional kurtosis (DK) maps were computed. Regions of interest (ROIs) were compared in 24 cerebral regions, including the frontal, parietal, and temporal lobe white matter (WM) in controls and NAWM in MS patients. Results The mean FA of all ROIs was 0.468 +/- A 0.014 (SD) (controls) or 0.431 +/- A 0.029 (MS group) (P = 0.016). Mean ADC was 0.785 +/- A 0.034 x 10(-3) mm(2)/s (controls) or 0.805 +/- A 0.041 x 10(-3) mm(2)/s (MS group). The mean DK of all ROIs was 0.878 +/- A 0.020 (controls) or 0.823 +/- A 0.032 (MS group) (P = 0.002). Analysis of individual ROIs revealed significant differences in DK in 3 ROIs between normal WM and NAWM, but significant differences in ADC and FA in only one ROI each. Conclusion DKI may be a new sensitive indicator for detecting tissue damage in MS patients in addition to conventional diffusional evaluations, for example diffusion tensor imaging.