Preoperative planning for a patient with a brainstem lesion and partial Parinaud syndrome. There are postoperative findings related to prior right transfrontal biopsy. There is redemonstration of a mildly expansile, infiltrative, T2 hyperintense lesion involving the left posterior limb of the internal capsule and midbrain, although the degree of associated enhancement appears to have diminished. There is mild residual right basal ganglia, cerebral peduncle, and pons T2 hyperintensity. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits are grossly unremarkable. There is mild scattered paranasal sinus mucosal thickening.
Preoperative planning MRI redemonstrates a lesion involving the left internal capsule and midbrain lesion with apparent decrease in the associated enhancement, which may be related to the natural course of the disease, treatment effects, and/or differences in MRI technique.