Berry aneurysm refers to dilated portion of blood vessel in Circle of Willis. It is an intracranial aneurysm. Berry aneurysm is the most common cause of subarachnoid hemorrhage. The attached image demonstrates the berry aneurysm on CT angiogram. Reference: https://radiopaedia.org/articles/saccular-cerebral-aneurysm Image via: https://www.semanticscholar.org/paper/Intracranial-Congenital-Berry%27s-Aneurysm%2C-Recurrent-Amin-Shukir/151d38d46608c10802cb33f540d216386f0fa16c/figure/2