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

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. •Diffuse correlation spectroscopy (DCS) for clinical and functional neuroimaging.•Optical measurement of cerebral blood flow (CBF) with DCS is presented.•Hybrid fNIRS and fDCS is presented as a method to measure cerebral metabolism.