Diffuse Correlation Spectroscopy (DCS): A Diagnostic Tool for Assessing Tissue Blood Flow in Vascular-Related Diseases and Therapies

The development and clinical application of a novel near-infrared diffuse correlation spectroscopy (DCS) have been reviewed in this paper. DCS measures speckle fluctuations of near-infrared diffuse light in tissue, which are sensitive to the motions of red blood cells. DCS offers several new features which make it appealing for blood flow measurement such as noninvasiveness, high temporal resolution (up to 100 Hz), portability, and relatively large penetration depth (up to ~1.5 centimeters). DCS technology can be utilized for bedside monitoring of tissue blood flow as exemplified by applications involving tumors, brains, and skeletal muscles. In these investigations, DCS measurements show promise for quantification of tissue hemodynamic status, for diagnosis of vascular-related diseases (e.g., cancers, stroke, peripheral arterial disease), and for continuous monitoring and evaluation of therapeutic effects (e.g., chemotherapy, radiation therapy, photodynamic therapy, arterial revascularization).