Abstract: This study investigated the value of CT angiography (CTA) and whole brain CT perfusion imaging (CTP) in assessing the establishment of collateral circulation and cerebral perfusion in patients with acute ischemic stroke (AIS), and analyzed the relationship between CTA, CTP and patient prognosis. 139 patients with AIS were selected for 256-slice spiral CT scan. According to the Glasgow outcome scale (GOS), the patients were divided into a good group with 95 cases and a poor group with 44 cases. Taking the detection results of DSA collateral circulation as the diagnostic gold standard, the sensitivity and specificity of CTA in diagnosing the establishment of intracranial arterial collateral circulation in patients with AIS were 95.12% and 91.23%, respectively. The scores of collateral circulation degree, cerebral blood volume (CBV), cerebral blood flow velocity (CBF), time to peak (TTP) and mean transit time (MTT) in the good group were higher than those in the poor group (P<0.05). Higher NIHSS score, larger infarct size, and cerebral vascular occlusion were independent risk factors of poor prognosis for AIS patients at admission (P<0.05). Good collateral circulation, higher levels of CBV and CBF cerebral perfusion are benefit for the recovery of patients' later prognosis (P<0.05). CTA has a higher sensitivity in detecting the establishment of intracranial arterial collateral circulation in patients with AIS. At the same time, early observation of the establishment of collateral circulation and cerebral perfusion level in patients has certain clinical value for evaluating the prognosis and recovery of patients.

Key words: acute ischemic stroke, CT angiography, whole brain CT perfusion imaging, collateral circulation, cerebral perfusion, prognosis