Vector-flow Imaging in Convex-array Configurations

Vector flow imaging (VFI) is a valuable diagnostic tool which is of particular interest when imaging tortuous vasculature. While VFI techniques have been extensively studied in linear-array configurations, the literature is lacking regarding convex-array geometries. We propose an ultrafast VFI technique suited to convex-array configurations based on sequential transmissions of multiple steered Archimedean-spiral wavefronts. We show that such wavefronts are highly directive in a well-chosen polar space which allows us to exploit multi-beam Doppler flow imaging techniques. We derive a flow-estimation method largely inspired from algorithms developed for plane-wave imaging, where the velocity components are extracted from their projections along the direction of the transmit beam. We validate the proposed technique through simulated experiments.