tl;dr: Researchers have developed a transcranial ultrasound technique that images brain vasculature through an intact skull at sub-millimeter resolution, leveraging FDA-approved microbubble contrast agents and super-resolution localization to beat the diffraction limit. They've produced what they claim is the most detailed vascular image of a living human brain via ultrasound, and are open-sourcing the pipeline and dataset. The longer-term goal is contrast-free neurovascular imaging for brain-computer interfaces, betting that cheaper hardware (à la Butterfly) plus end-to-end ML on raw ultrasound data will eventually extract neural activity signals without injected contrast.