An ultrasound imaging system (100) includes a velocity processor (118) that processes ultrasound data representing structure flowing through a tubular object and generates vector flow imaging information indicative of the structure flowing through a tubular object based thereon. The vector flow imaging information includes an axial velocity component signal and a lateral component signal, and the axial and lateral component signals indicate a direction and a speed of the structure flowing through the tubular object. The ultrasound imaging system further includes a flow parameter processor (120) that determines at least one flow parameter based on the vector flow imaging information and generates a signal indicative thereof.
