Calibrated BOLD using direct measurement of changes in venous oxygenation

► Venous blood oxygenation and CBV changes measured in response to a motor task. ► BOLD response to a motor task compared at normoxia and hyperoxia. ► BOLD calibration without assuming CBF/CBV coupling relationship. ► Motor task CMRO2 response of 18 ± 8% agrees with previous literature values.