Measuring the global cerebral metabolic rate of oxygen (CMRO2) is a valuable tool for assessing
brain vitality and function. Measurement of blood oxygen saturation (HbO2) and flow in the major
cerebral outflow and inflow vessels can provide a global estimate of CMRO2. We demonstrate a rapid
noninvasive method for quantifying CMRO2 by simultaneously measuring venous oxygen saturation
in the superior sagittal sinus with magnetic resonance susceptometry-based oximetry, a technique
that exploits the intrinsic susceptibility of deoxygenated hemoglobin, and the average blood inflow
rate with phase-contrast magnetic resonance imaging. The average venous HbO2, cerebral blood
flow, and global CMRO2 values in eight healthy, normal study subjects were 64%±4%, 45.2±3.2mL
per 100 g per minute, and 127±7 lmol per 100 g per minute, respectively. These values are in good
agreement with those reported in literature. The technique described is noninvasive, robust, and
reproducible for in vivo applications, making it ideal for use in clinical settings for assessing the
pathologies associated with dysregulation of cerebral metabolism. In addition, the short acquisition
time (B30 seconds) makes the technique suitable for studying the temporal variations in CMRO2 in
response to physiologic challenges.