Fast and selective super-resolution ultrasound in vivo with sono-switchable nanodroplets

Autor: Riemer, Kai, Toulemonde, Matthieu, Yan, Jipeng, Lerendegui, Marcelo, Stride, Eleanor, Weinberg, Peter D., Dunsby, Christopher, Tang, Meng-Xing
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1109/TMI.2022.3223554
Popis: 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 bubbles. 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 sono-switchable contrast agents were tested. We demonstrate their use with ultrasound mechanical indices well within recommended safety limits to enable fast on-demand sparse switching 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 an 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 and diastole with fast-AWSALM. In conclusion we demonstrate the feasibility of fast and selective measurement of microvascular dynamics in vivo with subwavelength resolution using ultrasound and sono-switchable nanodroplets.
Comment: phase-change contrast agent, low-boiling point nanodroplet, acoustic vaporization, droplet activation, microcirculation, contrast enhanced ultrasound, plane wave
Databáze: arXiv