In order to function properly, the brain requires a
steady flow of blood through the cerebral arteries and veins, which
deliver oxygen and nutrients and also remove metabolic byproducts.
Therefore, cerebral blood flow is considered a vital and sensitive
marker of cerebrovascular function. Optical methods offer a
noninvasive approach for measuring cerebral blood flow. Diffuse
correlation spectroscopy (DCS), a method gaining popularity,
involves the illumination of tissues with near-infrared laser rays.
The light is scattered by the movement of red blood cells and the
resulting pattern formed is analyzed by a detector to determine
blood flow.