Ultrafast ultrasound localization microscopy

Abstract

The resolution of ultrasound imaging is limited by the classical wave diffraction theory and corresponds roughly to the ultrasonic wavelength (from 0.2 to 1 mm for clinical applications). Current methods for in vivo microvascular imaging are limited by trade-offs between the depth of penetration and resolution. Inspired by the optical localization techniques (FPALM), we developed the technique ultrafast ultrasound superlocalization (uULM) where the resolution is not limited by the wavelength (Couture et al. 2011, Desailly et al. 2013). The use of ultrafast ultrasound acquisitions, based on plane wave transmissions at the rate of thousand frames per second, enabled the separation of million microbubbles achieving a resolution of about 8 μm at 12 mm depth for the vascular structure of the rat brain in-vivo (Errico et al., 2015). Moreover, we have lately demonstrated that by combining acoustic vaporization of composite droplets and rapid ultrasound monitoring, ultrasound drug-delivery can also be attained with subwavelength precision (Hingot et al., 2016).