Figure 4 (A-C): Complete tract disruption. A T2W axial image (A) shows a focal mass lesion (glioblastoma multiforme) (arrow) in the left corona radiata and basal ganglia. Directionally encoded color map shows distortion and altered color in the posterior limb of the left internal capsule (arrow). 3D tractography superimposed on an SPGR sequence shows cut-off of the left corticospinal fi bers (arrow), consistent with infiltration. The patient had right sided weakness prior to surgery, which as predicted by DTI, due to infiltration and cut-off of the corticospinal tracts, was not recovered after the surgery.