Findings:
A rather defined retro-cerebellar CSF intensity cyst is noted, with thin few anterior septae seen mass effect manifested as indentation of the posterior aspects of both cerebellar hemispheres, in keeping with a retrocerebellar communicating arachnoid cyst.
Mild involutional changes are seen in the brain parenchyma in the form of prominent cortical sulci and widened ventricles. No midline shift.
Multiple FLAIR hyperintense lesions in the supratentorial white matter, bandlike along the lateral ventricles, keeping with mild small vessel ischaemic disease.
Basal Ganglia Mineralisation with iron deposition in the globus pallidus on the SWI sequence as a normal ageing process. No abnormal signal on the susceptibility-weighted images or diffusion/ADC images.
The pituitary gland is normal.
The orbits, paranasal sinuses and mastoid air cells are clear.
No bony abnormality is seen. The craniocervical junction is normal.
Impression:
Incidental finding of a retrocerebellar arachnoid cyst.
Mild small vessel ischaemic disease.