Super-resolution ultrasound imaging with monodisperse microbubbles in a chicken embryo model

Abstract

ULM is a super-resolution imaging method that has transformed ultrasound imaging by beating the diffraction limit, enabling the visualization of blood vessel down to the capillary size. The development of innovative ultrasound responsive agents may allow to further improve the performance of this technology. Bracco is engaged in the formulation and the evaluation of various ultrasound responsive agents for ULM including monodisperse microbubbles. Our recent studies have shown that monodisperse microbubbles increase imaging sensitivity by an order of magnitude in comparison to polydisperse microbubbles. The benefit of this for ultrasound localization microscopy (ULM) has been tested in vitro in flow phantom and in a chicken embryo chorio-allantoic membrane (CAM) model. The performances of the monodisperse versus polydisperse formulations were evaluated through a collection of numeric metrics extracted from the super-resolved reconstructed CAM images, including not only quantitative criteria, such as the number of detected microbubbles or the rate of successful tracking, but also geometrical considerations such as vessel density or number of segments of the reconstructed vasculature. The study showed that monodisperse formulations outperformed the other polydisperse formulations, particularly using low to moderate microbubble concentrations.