The image on this slide is a blowup of the picture in the previous slide. The Spectral Doppler is the lower image and the B-mode is the image above and the color is the color flow overlay on top of the B-mode image. Looking at the Doppler image at the bottom, the scrolling spectral display indicates flow velocity on the X axis while the Y axis is time. The intensity of the image shows the strength of the flow of blood.