Fast and selective super-resolution ultrasound in vivo with acoustically activated nanodroplets
Author(s)
Type
Journal Article
Abstract
Perfusion by the microcirculation is key to the development, maintenance and pathology of tissue. Its measurement with high spatiotemporal resolution is consequently valuable but remains a challenge in deep tissue. Ultrasound Localization Microscopy (ULM) provides very high spatiotemporal resolution but the use of microbubbles requires low contrast agent concentrations, a long acquisition time, and gives little control over the spatial and temporal distribution of the microbubbles. The present study is the first to demonstrate Acoustic Wave Sparsely-Activated Localization Microscopy (AWSALM) and fast-AWSALM for in vivo super-resolution ultrasound imaging, offering contrast on demand and vascular selectivity. Three different formulations of acoustically activatable contrast agents were used. We demonstrate their use with ultrasound mechanical indices well within recommended safety limits to enable fast on-demand sparse activation and destruction at very high agent concentrations. We produce super-localization maps of the rabbit renal vasculature with acquisition times between 5.5 s and 0.25 s, and a 4-fold improvement in spatial resolution. We present the unique selectivity of AWSALM in visualizing specific vascular branches and downstream microvasculature, and we show super-localized kidney structures in systole (0.25 s) and diastole (0.25 s) with fast-AWSALM outdoing microbubble based ULM. In conclusion, we demonstrate the feasibility of fast and selective measurement of microvascular dynamics in vivo with subwavelength resolution using ultrasound and acoustically activatable nanodroplet contrast agents.
Date Issued
2023-04
Date Acceptance
2022-11-13
Citation
IEEE Transactions on Medical Imaging, 2023, 42 (4), pp.1056-1067
ISSN
0278-0062
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Start Page
1056
End Page
1067
Journal / Book Title
IEEE Transactions on Medical Imaging
Volume
42
Issue
4
Copyright Statement
© 2022 The Author(s). This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. For more information, see https://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://ieeexplore.ieee.org/document/9955557
Publication Status
Published
Date Publish Online
2022-11-18