Vessel Encoded Arterial Spin Labeling Evaluation of Collateral Circulation in Symptomatic and Asymptomatic Patients with Internal Carotid Artery or Middle Cerebral Artery Occlusion

Symptomatic and asymptomatic patients with internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion have the different prognosis. The present study had evaluated collateral circulation by Vessel Encoded Arterial Spin Labeling (VE-ASL) and cerebral vasoreactivity by mean transit time (MTT) obtained by Dynamic susceptibility contrast in symptomatic and asymptomatic patients with unilateral ICA and/or MCA occlusion. The study had found that the intensity of collateral in asymptomatic patients was significantly better than symptomatic patients while MTT showed no significant differences, which indicate that hemodynamic impairments in symptomatic patients with ICA/MCA occlusion may be mainly induced by the insufficiency of collateral circulation.