title: Direct measurement of tissue blood flow and metabolism with diffuse optics.
abstract: Diffuse optics has proven useful for quantitative assessment of tissue oxy- and deoxyhaemoglobin concentrations and, more recently, for measurement of microvascular blood flow. In this paper, we focus on the flow monitoring technique: diffuse correlation spectroscopy (DCS). Representative clinical and pre-clinical studies from our laboratory illustrate the potential of DCS. Validation of DCS blood flow indices in human brain and muscle is presented. Comparison of DCS with arterial spin-labelled MRI, xenon-CT and Doppler ultrasound shows good agreement (0.50<r<0.95) over a wide range of tissue types and source detector distances, corroborating the potential of the method to measure perfusion non-invasively and in vivo at the microvasculature level. All-optical measurements of cerebral oxygen metabolism in both rat brain, following middle cerebral artery occlusion, and human brain, during functional activation, are also described. In both situations, the use of combined DCS and diffuse optical spectroscopy/near-infrared spectroscopy to monitor changes in oxygen consumption by the tissue is demonstrated. Finally, recent results spanning from gene expression-induced angiogenic response to stroke care and cancer treatment monitoring are discussed. Collectively, the research illustrates the capability of DCS to quantitatively monitor perfusion from bench to bedside, providing results that match up both with literature findings and with similar experiments performed with other techniques.
authors: Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA. rickson@sas.upenn.edu
authors: Rickson C
authors: RC
authors: Mesquita
authors: Turgut
authors: T
authors: Durduran
authors: Guoqiang
authors: G
authors: Yu
authors: Erin M
authors: EM
authors: Buckley
authors: Meeri N
authors: MN
authors: Kim
authors: Chao
authors: C
authors: Zhou
authors: Regine
authors: R
authors: Choe
authors: Ulas
authors: U
authors: Sunar
authors: Arjun G
authors: AG
authors: Yodh
mesh_terms: D000818:Animals; D001703:Biophysics / Q000379:methods; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply; D002560:Cerebrovascular Circulation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D051379:Mice; D008962:Models, Theoretical; D009369:Neoplasms / Q000098:blood supply; D055095:Optics and Photonics; D010101:Oxygen Consumption; D051381:Rats; D013053:Spectrophotometry / Q000379:methods; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D013552:Swine; D018608:Ultrasonography, Doppler / Q000379:methods