Cerebrovascular reactivity mapping using intermittent breath modulation: temporal resolution dependence and comparisons with CO2 inhalation

Cerebrovascular reactivity (CVR) is typically measured using a carbon dioxide (CO2) stimulus combined with BOLD fMRI. However, this requires considerable subject cooperation. Although resting-state BOLD fMRI has shown its potential to generate CVR maps, the CVR results could be unreliable due to little fluctuation in some subjects’ spontaneous breathing. A new method utilizing intermittent breath modulation requires no gas-inhalation and presents higher sensitivity than resting-state CVR mapping. In this study, we investigated the effect of temporal resolution on CVR mapping obtained from breath modulation BOLD data. Our results showed that good CVR quality can be achieved with TR of 0.72s.