Vascular risk factors are suspected to play a role in the etiology of Alzheimer’s disease. Recently, a model that relates capillary dysfunction to the development of AD was proposed . The model predicts that increased capillary dysfunction leads to increased oxygen extraction in order to support the metabolic requirements of the brain tissues. In this study we investigated the brain oxygen extraction capacity (OEFmax) in AD patients and controls using dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI). Increased OEFmax was detected in the temporal, parietal and frontal lobes of AD patients compared to controls. These findings are consistent with the capillary dysfunction hypothesis of AD . The widespread cortical atrophy and smaller hippocampal volumes in the AD patients suggest pathologies of late Braak stages. Further studies should address the causal relation between elevated OEFmax and atrophy.