Velocity vector in three dimensions using a high-frame-rate dual-transducer setup

High-frame-rate ultrasound imaging has great potential to improve conventional Doppler imaging because large ensemble acquisitions are available for every pixel in an image. Additionally it allows deriving the lateral motion using angled plane-wave beams. Despite its clinical success, conventional Doppler techniques remain limited due to the inability to measure out-of-plane flow. In this paper we present a solution for measuring all flow directions by using two linear array transducers with overlapping beams. By triangulation of the 2D Doppler signals derived for the individual imaging planes we derive the full 3D velocity vector. We show experimental proof that this imaging setup allows to extract the 3D velocity vector of blood in a human carotid artery.