Figure 5. (a) An axial T2W series through the brainstem of a 2 year old with neurofibromatosis and recent cranial nerve palsy shows swelling of the pons but with little signal change. (b) The sagittal T1W images through the midline confirmed the swelling but no enhancement. (c) A PET scan with methionine (above) and FDG (below) showed increased uptake, making biopsy likely to be of benefit despite the hazardous site. A fibrillary grade II astrocytoma was confirmed.