An ultrasound imaging system includes an image processor and a velocity processor configured to process beamformed ultrasound data representing structure flowing through a tubular object and generate, respectively, an image indicative of the tubular object and vector flow imaging data indicative of the structure flowing through the tubular object. The system further includes a segmentation processor configured to segment the tubular object from the image based on a combination of both the vector flow imaging data and the image, wherein a resulting segmentation extends from wall-to-wall of the tubular object. The system further includes a display configured to display the image with the segmentation and the vector flow imaging data superimposed thereover, with the vector flow imaging data extending from wall-to-wall within the tubular object. The system further includes the automatic computation of largest vessel diameter (Dmax), and/or quantitative flow measures such as Peak systolic velocity (PSV) and/or volume flow.
