This book examines Dynamic Light Scattering (DLS) and its derivatives Laser Doppler Flowmetry (LDF), Diffusing Wave Spectroscopy (DWS), Laser Speckle Contrast Imaging (LSCI), and Doppler Optical Coherence Tomography (OCT) for characterizing particle motion in turbid mediums like suspensions and solutions. It focuses on non-invasive blood flow imaging in biological tissues, detailing technological advancements, practical applications, and inherent challenges. Essential for professionals in biomedical optics and medical fields, as well as physics and engineering students, the book highlights its use in brain, skin, and micro-circulation studies, providing key insights and practical guidance. Key Features: Presents a deep dive into DLS and its derivative techniques. Emphasizes practical applications, including brain blood flow monitoring, skin perfusion measurements, and micro-circulation characterization. Delivers insights into the challenges and limitations associated with DLS-based blood flow imaging.