Advances in Dynamic Light Scattering Imaging of Blood Flow

Dynamic light scattering (DLS) is a well known experimental approach uniquely suited for the characterization of small particles undergoing Brownian motion in randomly inhomogeneous turbid scattering medium, including water suspension, polymers in solutions, cells cultures, and so on. DLS is based on the illuminating of turbid medium with a coherent laser light and further analyzes the intensity fluctuations caused by the motion of the scattering particles. The DLS-based spin-off derivative techniques, such laser Doppler flowmetry (LDF), diffusing wave spectroscopy (DWS), laser speckle contrast imaging (LSCI), and Doppler optical coherence tomography (DOCT), are exploited widely for non-invasive imaging of blood flow in brain, skin, muscles, and other biological tissues. The recent advancements in the DLS-based imaging technologies in frame of their application for brain blood flow monitoring, skin perfusion measurements, and non-invasive blood micro-circulation characterization are overviewed. The fundamentals, breakthrough potential, and practical findings revealed by DLS-based blood flow imaging studies, including the limitations and challenges of the approach such as movement artifacts, non-ergodicity, and overcoming high scattering properties of studied medium, are also discussed. It is concluded that continued research and further technological advancements in DLS-based imaging will pave the way for new exciting developments and insights into blood flow diagnostic imaging.