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bioRxiv · 10.1101/2021.03.25.437094

Quantitative blood flow estimation in vivo by optical speckle image velocimetry

Qureshi, M. M.·Liu, Y.·Mac, K. D.·Kim, M.·Safi, A. M.·Chung, E.
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Abstract

Speckle based methods are popular non-invasive, label-free full-field optical techniques for imaging blood flow maps at single vessel resolution with a high temporal resolution. However, conventional speckle approach cannot provide an absolute velocity map with magnitude and direction. Here, we report a novel optical speckle image velocimetry (OSIV) technique for measuring the quantitative blood flow vector map by utilizing particle image velocimetry with speckle cross-correlations. We demonstrate that our OSIV instrument has a linearity range up to 7 mm/s, higher than conventional optical methods. Our method can measure the absolute flow vector map at up to 190 Hz without sacrificing the image size, and it eliminates the need for a high-speed camera/detector. We applied OSIV to image the blood flow in a mouse brain, and as a proof of concept, imaged the real-time dynamic changes in the cortical blood flow field during the stroke process in vivo. Our wide-field quantitative flow measurement OSIV method without the need of tracers provides a valuable tool for studying the healthy and diseased brain.

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Qureshi, M. M., Liu, Y., Mac, K. D., Kim, M., Safi, A. M., Chung, E.. 2021-03-25. Quantitative blood flow estimation in vivo by optical speckle image velocimetry. https://doi.org/10.1101/2021.03.25.437094

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