Kevin Murphy1, Molly G. Bright1
1CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom
Cerebrovascular reactivity, the vascular response to vasodilatory stimuli, can be measured with BOLD fMRI by increasing end-tidal CO2 using a breath-hold task. A long end-expiration breath-hold lasting 20s provides a suitably large BOLD response. However, clinical and elderly populations may find such a long breath-hold difficult and it is likely that the length of breath-hold that each participant can achieve will vary widely across these groups. This study demonstrates that by measuring end-tidal CO2 changes during a breath-hold task, a repeatable measure of cerebrovascular reactivity can be obtained irrespective of whether the participant can perform the task fully or consistently.