Assessment of Cerebral Collaterals in Acute Ischemic Stroke by CT Cerebral Angiography and Its Relation to the Functional Outcome

Ischemia is the main cause of stroke, typically due to the occlusion of a cerebral artery as a result of progressive atherosclerosis or an embolus from the heart or neck vessels (Truelsen et al., 2006). In some patients the blockage or occlusion can develop within small intracranial vessels, often because of uncontrolled hypertension or diabetes (Adams et al., 1993). Irrespective of the cause or mechanism of ischemia, collateral flow “i.e, perfusion via alternative or indirect pathways” might off set potential injury to the brain (Liebeskind, 2007).