AbstractDoppler principle allows determination of the velocity and direction of motion of the moving objects. One can understand this principle by imagining one-. self stationed at a platform.Most blood flows in the living vessels are laminar. It is a ‘quiet’ blood flow and the blood moves in layers which slide over each other. The layers which are closer to the vessel wall move relatively slowly than those layers which are located in the centre of the vessel.In this technology cardiac imagining and Doppler blood flows are recorded separately and are even tually matched so that Doppler information is placed within the images.The color flow mapping technique allows ‘resolution of aliased velocities’ by introducing yellow colour code for the turbulent flow. So that high velocity flow appears as combination of red, blue, yellow so that multicolour flows suggest high velocity turbulent flows.