Coloured computed tomography (CT) angiogram in posterior polar anatomical view (view located next to the polygon of Willis) of a 46-year-old male patient, presenting with subarachnoid hemorrhage. SAH is a rare, life-threatening type of stroke caused by bleeding into the space surrounding the brain (subarachnoid space). This bleed is caused by a large aneurysm (distended, weakend, blood vessel wall, pink) at the right middle cerebral artery.