 MRI ORBITS AND BRAIN/SKULLBASE: No abnormal mass or abnormal enhancement is seen within the orbits. There is abnormal T2/STIR hyperintensity involving the left optic nerve, relatively more prominent posteriorly, coronal STIR series 1501 image 19 without enhancement or mass. The subtle finding also appears to be present on prior study from 5/25/2016. Optic chiasm is unremarkable. Extraocular muscles are unremarkable.There is no appreciable lesion within the left cavernous sinus, parasellar region or orbital apex. There is mild ectasia and tortuosity of the left cavernous and paraclinoid internal carotid artery which produces asymmetric fullness of the left cavernous sinus.There is an enhancing T2 hypointense lesion at the right cerebellopontine angle extending into the right internal auditory canal measuring 7 mm in the craniocaudal dimension and approximately 19 mm in the longitudinal dimension and 10 mm in the short axis/AP dimension. No significant change in size since prior. There is no mass effect on the brainstem. No mass or gross signal abnormality involving the cochlea or semicircular canals.Brain parenchyma is partially imaged but there is no evidence of intraparenchymal mass or mass effect. No midline shift or herniation. There is moderate degree of global parenchymal volume loss commensurate patient's age. There are also multiple foci of T2 hyperintensity in the bilateral periventricular and subcortical white matter which are nonspecific but compatible with mild chronic small vessel ischemic disease. No hydrocephalus. No extra-axial collections.There is partial opacification of the superior right-sided mastoid air cells with T2 and intrinsic T1 hyperintensity which was also present on prior MRI from 5/25/2016. There may be dehiscence involving the tegmen mastoideum which can be better assessed with CT.MRA HEAD: There are fenestrations at the level of the anterior communicating artery as well as involving the mid to distal basilar artery along the left lateral wall. The intracranial internal carotid arteries demonstrate no significant stenosis. The middle and anterior cerebral arteries are also patent. The vertebral arteries, basilar artery, and posterior cerebral arteries also are patent with no significant stenosis. No evidence of aneurysms or vascular malformations.
1. Unchanged 19 x 10 x 7 mm enhancing lesion in the right internal auditory canal extending into the cerebellopontine angle consistent with vascular schwannoma. No mass effect on the brainstem.2. There is no lesion within the left cavernous sinus. There is tortuosity of the left cavernous and paraclinoid internal carotid artery which produces the apparent asymmetric fullness of the left cavernous sinus.3. Subtle T2 hyperintensity in the left optic nerve which also appears to be present on prior study from 5/25/2016. Finding may represent sequela of prior optic neuritis or other injury.4. Mild chronic small vessel ischemic disease and brain parenchymal volume loss.5. Partial opacification of the superior right-sided mastoid air cells with T1 hyperintensity. This finding was also present on prior study. Findings may represent proteinaceous fluid or perhaps blood products related to chronic inflammation. There may be dehiscence involving the tegmen mastoideum which can be better assessed with CT.