Is there an abnormality?
Yes. A 3mm globular region of enhancement likely represents a PICA aneurysm.
Is there a differential diagnosis?
It is possible that the aneurysm represents an in-flow aneurysm, part of an unseen vascular malformation. A mycotic or false aneurysm from dissection is a possibility.
A globular region of arterial enhancement is demonstrated just to the left of midline, within the vermian sulci which presumably represents a distal PICA aneurysm measuring 3mm. No definite vascular intracranial abnormality identified.