Fig 19.

DTI pattern 1: normal anisotropy, abnormal location or orientation.

A–E, T2-weighted MR image (A), contrast-enhanced T1-weighted image (B), directional maps in axial (C) and coronal (D) planes, and coronal tractogram of bilateral corticospinal tracts (E). WM tracts are deviated anteriorly, inferiorly, and posterolaterally by this ganglioglioma but retain their normal anisotropy. Therefore, they remain readily identified on DTI (C and D) and readily traced with tractography (E). The AC (red, arrowhead), IOFF (green, open arrow), and CST (blue, solid arrows) are deviated. Note the blue hue of the CST change to red as it deviates toward the axial plane by the tumor (arrow on coronal view [D]).