Fig 2. Axial T1-weighted MR image of a patient with a brain tumor with fibers of the corticospinal tract projected in color. Results from conventional fiber tracking based on anatomic landmarks (in orange) show dispersion and diminished visualization of the CST fibers in the hemisphere affected by the lesion (arrowheads), compared with the unaffected hemisphere. DT tractography based on seed region-of-interest selection in the PMA of the hand as established with fMRI shows, in blue, the CST fibers of the hand in the affected hemisphere, allowing a clear demarcation of the fibers of interest within the CST.