Fig 4. MR image, obtained 13 months after surgery, of a 46-year-old woman with a large cerebellopontine angle meningioma. A 3-mm-thick FSE T2-weighted image obtained at the level of the middle cerebellar peduncle shows atrophic change of the right middle cerebellar peduncle and right cerebellar hemisphere, with a dilated fourth ventricle secondary to infarction in the right anterior inferior cerebellar artery distribution (distal AICA syndrome). Most of the meningioma was removed, but a residual tumor is seen in the enlarged right internal auditory canal as an isointensity lesion (arrow). No focal hyperintensity lesion is observed in the dorsal brain stem.