Fig. 5.

Pilocytic tumor in a 3-year-old child presenting with spastic hemiparesis. A: Axial T2-weighted MR image showing displacement of the thalamus anterior and posterior to the tumor. B: A DT imaging color map. The arrows (tracts in blue) designate the CST. C: A fractional anisotropy map demonstrating that in this case the CSTs (arrows) were draped around the lateral aspect of the tumor, which made a lateral approach unattractive. D and E: Sagittal T1-weighted MR images showing previous biopsy track; note enhancement of the track. F: The authors chose to use the previous biopsy track, a transfrontal corticotomy, to remove the tumor; the patient’s hemiparesis improved postoperatively.