Enlargement of his lateral and third ventricles in the setting of aqueduct stenosis, caused by a small glioma: yearly follow up. There is a non-enhancing, slightly T2 hyperintense lesion in the left periaqueductal region of the midbrain that measures up to approximately 5 mm. There is associated narrowing of the superior cerebral aqueduct and dilation of the third and lateral ventricles, which is unchanged. Indeed, there is no discernible cerebrospinal fluid flow across the aqueduct of Sylvius. There is unchanged mild periventricular T2 hyperintensity. There is no evidence of intracranial hemorrhage or acute infarct. There is no midline shift or herniation. The skull and extracranial soft tissues are unremarkable.
Unchanged subcentimeter lesion in the left periaqueductal region of the midbrain with associated narrowing of the superior cerebral aqueduct and obstructive hydrocephalus. 