Fig 12. Pre- (A) and postoperative (B) tractograms of the ipsilateral and contralateral corticospinal tracts for patient 5. C and D, The corresponding tract positions in the coronal plane are shown before and after surgery, respectively. Preoperatively, the ipsilateral tract appears to be deviated medially due to the mass effect of the tumor (yellow arrows). Postoperatively, the tract returns to a more normal anatomic position (white arrow). An FA threshold of 0.15 was used to terminate trajectories for both pre- and postoperative tractograms.