CTA can be used assess acute stroke patients by identifying clots in the arteries of the brain. It can also be used to identify small aneurysms or arteriovenous malformation inside the brain that can be life-threatening. While CTA can produce high quality images of the carotid arteries for grading the level of stenosis (narrowing of the vessel), calcium deposits (calcified plaques) in the area where the vessels split can lead to interference with accurate stenosis grading. Because of this, magnetic resonance angiography is used more often for this purpose. Other applications of CTA are identifying moyamoya disease, dissections of intracranial arteries, detection of carotid-cavernous fistula, planning for intracranial-extracranial bypass surgery, and involvement of brain tumours such as meningioma with surrounding intracranial vessels.
