Super-resolution Ultrasound Imaging

Summury : Ultrasound is a widely used medical imaging technique that is sensitive to blood flow. However, it is limited by a classical trade-off between penetration and resolution. In particular, brain imaging and angiography using ultrasound are compromised by the skull, which attenuates acoustic waves, especially those that could provide submillimeter details.

Ultrasound Localization Microscopy (ULM) is a novel technique that offers very high resolution deep within tissues. It relies on clinical contrast agents—specifically, intravascular microbubbles—that are isolated and localized at the micrometric scale in ultrasound images. Tracking their movement can yield blood velocities in the microvasculature. This technique has been demonstrated in various contexts, including the brain (Errico et al., Nature 2015), as well as in the kidney, tumors, peripheral vessels, lymph nodes, and more, both preclinically and clinically.

In this presentation, we will describe recent advances in ULM, particularly focusing on 3D reconstruction of rat brain hemodynamics at the microvascular scale. We will also present angiography of the entire brain at this scale, highlighting its sensitivity to stroke models. Additionally, we will discuss the current results of clinical trials. Furthermore, we will introduce sensing-ULM, which provides access to the microvasculature of functional units, such as glomeruli, in both animals and humans.

In our laboratory, these developments are aimed at creating a new imaging tool for stroke patients in critical care. In the future, ULM could indeed facilitate deep angiography, potentially reducing treatment time for ischemic patients.

Bio : Olivier Couture was born in Quebec City (Canada) in 1978. He received his B.Sc degree in physics from McGill University, Montreal, Canada, in 2001, and his Ph.D degree from the department of Medical Biophysics, University of Toronto, Canada, in 2007. After a postdoctoral fellowship at ESPCI in Paris (France), he was hired as a research associate at CNRS, based within the Langevin Institute. In 2019, he moved to Laboratoire d’Imagerie Biomédicale (LIB, Sorbonne Université) as a research director to head the team Physiology and Pathology of Microcirculation and, later, co-supervise the Medical Ultrasound team of the LIB. He was awarded the CNRS Bronze Medal and the 2017 IEEE Ultrasonics Early Career Investigator Award for introducing super-resolution ultrasound through microbubble localization. He is the principal investigator of the ERC Consolidator Grant “ResolveStroke”, the ERC POC StrokeMonitor and the ERC POC KidneyScope. He is also the cofounder of the startup ResolveStroke.