Why does the patient have a headache?
On sagittal imaging, what features are present in the third ventricle which indicate hydrocephalus?
There is inferior bowing of the floor of the third ventricle with ballooning out of the supraoptic and infundibular recesses.
Where is the obstruction and what is it due to?
A cystic pineal lesion has extended anteriorly and prolapsed into the superior aspect of the aqueduct.
A lobulated 14 x 8 mm pineal cyst projects anteriorly to obstruct the upper margin of the cerebral aqueduct, with mild to moderate hydrocephalus and mild periventricular (transependymal) signal abnormality.
Several small T2 hyperintense lesions, measuring up to 5 mm diameter inferiorly in the right pre-central gyrus, are in keeping with chronic small vessel ischaemic change, a little greater than expected for the patient's age, with no associated diffusion restriction or magnetic susceptibility. The remainder of the study is unremarkable.