Laser speckle contrast imaging of the skin: interest in processing the perfusion data

Laser speckle contrast imaging (LSCI) is a recent clinical powerful tool to obtain full-field images of microvascular blood perfusion. The technique relies on laser speckle obtained by the interactions between coherent monochromatic radiations and the tissues under study. From these speckle images, contrast values are determined and instantaneous map of the perfusion are computed. LSCI has gained increased attention in the last years and is now additional to laser Doppler flowmetry (LDF). In spite of the growing interest for LSCI in skin clinical research, very few LSCI perfusion data processing have been published from now to extract physiologically-linked indices. By opposition, numerous signal processing works have been dedicated to the processing of LDF signals. The latter works proposed methodological processing procedures to extract information reflecting underlying microvascular mechanisms such as myogenic, neurogenic and endothelial activities. Our goal herein is to report on the potentialities of studies dedicated to the processing of LSCI perfusion data. Linear and nonlinear analyses could be of interest to improve the understanding of LSCI images.