Paula L. Croal1, Emma L. Hall1, Ian D. Driver1, Penny A. Gowland1, Susan T. Francis1
1Sir Peter Mansfield MR Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
Local CBF (LCBF) is currently thought to increase on cortical activation to meet an increased demand in oxidative metabolism. However, animal literature suggests that this increase is dominated by a change in the vascular reactivity, as the LCBF response is higher with hyperoxia. This study measures the LCBF response in the human motor cortex on hyperoxia using LL-FAIR-ASL. A trend was seen, with hyperoxia increasing the LCBF response and reducing transit times to a greater extent than normoxia. This finding raises questions as to whether the role of functional hyperaemia is driven by changes in metabolic demand or vasculature reactivity.