Witt, Atlee A., Fleishman, Sawyer, Houston, Delaney C., Prock, Logan E., Sweeney, Grace, McGonigle, Trey William, Vandekar, Simon N., Chamberland, Maxime, Stubblefield, Seth, & McKnight, Colin David. (2025). “Tract-specific analysis of diffusion MRI at 3T detects cervical spinal cord aberrations in multiple sclerosis.” Imaging Neuroscience, 3, IMAG.a.72. https://doi.org/10.1162/IMAG.a.72
In people with multiple sclerosis (MS), imaging techniques like diffusion tensor imaging (DTI) can detect damage in the spinal cord before major symptoms appear, but these methods are not very specific. Diffusion tensor tractographygoes a step further by mapping the paths of nerve fibers, and while it’s widely used in the brain, it hasn’t been fully explored in the spinal cord of people with relapsing-remitting MS (pwRRMS).
In this study, we examined the paths of nerve fibers in the cervical spinal cord of 56 pwRRMS and 46 healthy controls using a 3T MRI scanner. We looked not only at overall lesion load but also at lesions and diffusion patterns within specific white matter columns and along individual fiber paths. We found that fractional anisotropy (FA), a measure of microstructural integrity, was lower in women and older participants, though this effect was less pronounced along the fiber paths themselves. We also found no significant links between these imaging measures and clinical symptoms.
Overall, while spinal cord tractography may be useful for visualizing nerve fiber paths, it did not provide clear advantages over conventional imaging methods in detecting MS-related damage.
Fig.1. In addition to the single shell diffusion acquisition (15 directions, b = 750 s/mm2) centered between cervical levels C3 and C4, the protocol included a sagittal T2-weighted turbo spin echo and mFFE axial anatomical scan (A). The mFFE, diffusion b0, and FA maps are included for a 27.5-year-old HC and 26.4-year-old pwRRMS with a lesion identified via the yellow arrow (B). (C) Tractography is included for a 23.6-year-old HC (C1) as visualized via MI-Brain and FiberNavigator. The white matter fiber tracts are split into six bundles (left and right ventral, lateral, and dorsal) with a gray matter mask overlaid on the axial view of the anatomic mFFE image (C2). For a 29.8-year-old pwRRMS, two streamline bundles (right dorsal, right lateral) are highlighted in blue, with the streamlines touching lesions highlighted in pink. The right dorsal tract demonstrates low streamline bundle load, while the right lateral tract demonstrates high streamline bundle load (C3). The right lateral lesion can be easily visualized on the axial view of the anatomic mFFE (yellow arrow) (C4).