Near Infrared Determined Cerebral Transit Time and Oxy- and Deoxyhemoglobin Relationships During Hemorrhagic Hypotension in the Dog

Abstract
Many recent papers suggest that in patients with cerebrovascular diseases, cerebral blood flow (CBF) measurement alone is a poor indicator of hemodynamic reserve (Gibbs et al., 1984). A usual finding of positron emission tomography studies is a fall of the CBF/cerebral blood volume (CBV) ratio, mathematically equivalent to an increase of the mean transit time (MTT) (Zierler, 1965).