Print Email Facebook Twitter Retrieving pulsatility in ultrasound localization microscopy Title Retrieving pulsatility in ultrasound localization microscopy Author Wiersma, Myrthe (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Delft Center for Systems and Control) Contributor Heiles, B.G. (mentor) Kalisvaart, D. (mentor) Maresca, D. (mentor) Smith, C.S. (mentor) van de Plas, R. (graduation committee) Verbiest, G.J. (graduation committee) Degree granting institution Delft University of Technology Programme Mechanical Engineering | Systems and Control Date 2022-05-20 Abstract Ultrafast ultrasound localization microscopy (ULM) is a super-resolved vascular imaging method that provides a 10-fold improvement in resolution compared to ultrafast ultrasound Doppler imaging. Because typical ULM acquisitions accumulate large numbers of synthetic microbubble (MB) tracks over hundreds of cardiac cycles, transient hemodynamic variations such as pulsatility get averaged out. Here we introduce two independent processing methods to retrieve pulsatile flow information from MB tracks sampled at kilohertz framerates and demonstrate their potential on a simulated dataset. Our first approach filters out ULM localization grid artifacts and successfully recovers the pulsatility fraction Pf with a root mean square error of 3.3%. Our second approach relies on the derivation of the velocity distribution of MBs as observed from a stationary observer. We show that pulsatile flow gives rise to a bimodal velocity distribution with peaks indicating the maximum and minimum velocity of the cardiac cycle. Measuring the locations of these peaks, we successfully estimated Pf with an error of 5.2%. Last, we evaluated the impact of the MB localization precision σ on our ability to retrieve the bimodal signature of a pulsatile flow. Together, our results demonstrate that pulsatility can be retrieved from high framerate ULM acquisitions and that the estimation of the pulsatility fraction improves with MB localization precision. Subject ultrasound localization microscopypulsatilitylocalization precisionvelocity distribution To reference this document use: http://resolver.tudelft.nl/uuid:21c152eb-aee7-4376-b4bb-70a35b8c02e5 Part of collection Student theses Document type master thesis Rights © 2022 Myrthe Wiersma Files PDF Msc_Thesis_Myrthe_Wiersma.pdf 18.75 MB Close viewer /islandora/object/uuid:21c152eb-aee7-4376-b4bb-70a35b8c02e5/datastream/OBJ/view