This study evaluates cerebral perfusion and cerebrovascular reserve (CVR) in impaired glucose tolerance and patients with type-2 diabetes using QUASAR Arterial Spin Labeling. CVR was evaluated as the change in gray matter CBF in response to a pharmacological stimulus. The developed processing pipeline was based on published QUASAR theory, modified to account for excessive motion and partial volume effects. Results show that baseline CBF is within the expected range. In patients with T2DM and IGT there is a significantly lower value of Cerebrovascular Reserve compared to healthy, normoglycaemic individuals.