Abstract #3483

Determination of Maximum BOLD Calibration Constant Using Hyperoxia.

Daniel Bulte¹, Molly Bright^1,2, Peter Jezzard¹

¹FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom; ²National Institutes of Health (NIH), Bethesda, MD, United States

Calculation of the maximum theoretical BOLD signal change (M) has been achieved using short epochs of mild hyperoxia. This value can be used to produce estimates of the change in CMRO2 during functional tasks. This study seeks to minimise the number and duration of hyperoxic blocks needed to determine this value. 2x2 minute blocks of mild hyperoxia are shown to be sufficient to produce reliable results, reducing the total time needed to be added to a scan to 8 minutes.