Abstract: A method for measuring and displaying flow and flow volume in the vessel of a subject. The method includes acquiring ultrasound data from a subject and producing a color Doppler m-mode image depicting the vessel. A 3D representation of the color Doppler m-mode image is then generated to enable an operator to identify the blood vessel and window the ultrasound data accordingly to a selected range of heart beats. Blood vessel walls are automatically identified from the windowed ultrasound data and blood flow through the vessel lumen is measured using pulsed Doppler ultrasound, which is gated to substantially exclude data from outside the lumen. Volume flow through the vessel is determined by multiplying the measured blood flow with a calculated cross-sectional area of the vessel and an image indicative of the volume is then generated and displayed.