High-speed dynamic laser speckle imaging of changes of microcirculation in vivo

Abstract

In this study, we aims to evaluate the capability of a new developed laser speckle contrast imaging (LSCI) system for mapping microvascular perfusion and to demonstrate the capability of LSCI to assess transient change of blood perfusion with high flow sensitivity. Through well defined phantom experiments, we found that there is a critical point that divides the velocity domain into two halves, one half that is below the critical point where the higher the velocity, the higher the speckle contrast is; and it is however opposite in the other half. Our study shows that the increasing of the camera exposure time value causes decreasing of the critical point value. For the first time, this finding is proposed and provides a novel explanation about the laser speckle temporal contrast imaging (LSTCI). To further validate, measurements were performed on mouse ear flap during occlusion of the root artery circulation to modify the whole mouse ear flap perfusion. Finally, the speckle contrast maps of dynamic microvascular blood flow in the mouse ear flap were demonstrated. The promising results show that the LSCI system can give useful information as to blood flow change.