Photoacoustic (PA) imaging can be used to monitor flowing blood inside the microvascular and capillary bed. Ultrasound speckle decorrelation based velocimetry imaging was previously shown to accurately estimate blood flow velocity in mouse brain (micro-)vasculature. Translating this method to photoacoustic imaging will allow simultaneous imaging of flow velocity and extracting functional parameters like blood oxygenation. In this study, we use a pulsed laser diode and a quantitative method based on normalized first order field autocorrelation function of PA field fluctuations to estimate flow velocities in an ink tube phantom and in the microvasculature of the chorioallantoic membrane of a chicken embryo. We demonstrate how the decorrelation time of signals acquired over frames are related to the flow speed and show that the PA flow analysis based on this approach is an angle independent flow velocity imaging method.
Bibliographical noteFunding Information:
Klazina Kooiman (SM’18) received the M.Sc. degree (cum laude) in biopharmaceutical sciences specializing in pharmaceutical technology from Leiden University, Leiden, The Netherlands, and the Ph.D. degree in ultrasound contrast agents for therapy from the Department of Biomedical Engineering, Thoraxcenter, Erasmus MC University Medical Center Rotterdam, The Netherlands, in 2011. In 2018, she acquired the prestigious ERC starting grant from the European Research Council, and in 2019 the prestigious Vidi Grant from the Netherlands Organization for Scientific Research, domain Applied and Engineering Sciences. She is currently an Associate Professor and the Head of the Therapeutic Ultrasound Contrast Agent Group, Department of Biomedical Engineering, Thoraxcenter, Erasmus MC University Medical Center, focusing on using ultrasound contrast agents for drug delivery and molecular imaging. Dr. Kooiman was a recipient of the EFUSMB 2011 Young Investigator Award, Vienna, Austria. She is the co-director of the Annual European Symposium on Ultrasound Contrast Imaging, Rotterdam, which is attended by approximately 180 scientists from universities and industries all over the world.
This work is part of the Vici grant 16131 which is financed by the Dutch Research Council (NWO).
© 2021 The Author(s)