Full-field amplitude speckle decorrelation angiography

We propose a new simple and cost-effective optical imaging technique, full-field amplitude speckle decorrelation angiography (FASDA), that can be implemented with cameras with conventional frame rates, does not require raster scanning, and is capable of classifying vessels into superficial and deep. The proposed imaging technique is based on the simultaneous evaluation of two metrics: the blood flow index, a contrast-based metric used in laser speckle contrast imaging, and the adaptive speckle decorrelation index (ASDI), a new metric that we defined based on the second-order autocorrelation function that considers the limited speckle modulation that occurs in partially-coherent imaging. We demonstrate excellent delineation of superficial vessels in skin nevi using ASDI and deeper vessels using BFI, providing a powerful new tool for the imaging of microvasculature with significantly lower hardware complexity than other optical imaging techniques.