Diffuse correlation spectroscopy for non-invasive, micro-vascular cerebral blood flow measurement

摘要

Diffuse correlation spectroscopy (DCS) uses the temporal fluctuations of near-infrared (NIR) light to measure cerebral blood flow (CBF) non-invasively. Here, we provide a brief history of DCS applications in the brain with an emphasis on the underlying physical ideas, common instrumentation and validation. Then we describe recent clinical research that employs DCS-measured CBF as a biomarker of patient well-being, and as an indicator of hemodynamic and metabolic responses to functional stimuli.Cerebral well-being depends on adequate cerebral blood flow (CBF) for oxygen delivery and clearance of the byproducts of metabolism. Cerebral tissues receive about 20% of the body's oxygen, and the majority of this oxygen is consumed in the process of metabolism via aerobic mechanisms (Siesjo, 1978; Zauner et al., 2002). Thus, CBF is an important biomarker of brain health and function. It is a critical physiological parameter linking metabolic demand to oxygen supply, oxygen supply to metabolic consumption, and metabolic consumption to byproduct clearance. Furthermore, CBF impairment is a direct cause of dangerous clinical conditions such as ischemic stroke, and its dynamic alteration is integral to brain auto-regulation.