Echo-planar MR imaging of human brain oxygenation changes.

Echo-planar magnetic resonance (MR) imaging was used to observe signal intensity changes in the human brain during hypoxia. Increasing arterial blood levels of deoxyhemoglobin (0%-42%) during prolonged apnea were monitored with a pulse oximeter and correlated with gray matter and white matter signal attenuation of 13% and 20%, respectively. The results suggest the possibility of using deoxyhemoglobin boluses as a physiologic, intravascular susceptibility contrast agent for assessment of local cerebral oxygen utilization.