Flow information can be overwhelming in medical color flow images, including volume color Doppler imaging and vector flow imaging. The flow of interest can be obscured or concealed by the adjacent flows in the displayed images. To enhance the color flow display and highlight the flow of interest, the transparency or opacity for each pixel or voxel in the flow data is modulated. Rather than or in addition to relying on color Doppler parameters, such as velocity amplitude, energy and variance, the direction of the flow is used to modulate transparency.
