Lumius

Lumius is the 3D ultrasound play that just raised its hand in the medical imaging space, and honestly, Y Combinator's backing gives them some credibility to take the idea seriously. They're starting with image-guided vascular access as their wedge — a smart move when you're taking on the radiology giants, because you're not trying to replace the whole machine, just make one specific procedure better. The pitch is real-time volumetric imaging at a price that works for outpatient clinics and ERs rather than just hospital radiology departments with fat budgets. Whether they've actually nailed the image quality and clinical workflow integration that matters to doctors is the thing nobody can say yet, but the YC badge is at least worth tracking.