Conventional tractography excludes acute directional changes. We define these acute changes as tortuosity and use it to characterize gray-white matter boundaries, as well as quantify deformation and remodeling in pathologic states. Five healthy volunteers and a brain tumor patient were scanned using the gSlider-SMS technique. Diffusion data was processed to create 3D contiguous ribbons that characterize tortuosity. Twisting angles of the 3D ribbons were compared within and between subjects, and were visually and statistically consistent. This highly informative tractographic method could be applied to evaluate tumor infiltration and adjacent brain compression, or traumatic brain injury.