Doppler ultrasound screens for cardiovascular disease; similar to echocardiography, Doppler ultrasound (or Doppler echocardiography) is a test. During a Doppler ultrasound, very high-frequency sound waves are reflected back from the heart and blood vessels, and the returning sound waves (echoes) are picked up and turned into a picture that shows the flow of blood through the arteries or the heart itself; Doppler ultrasound testing allows the doctor to clearly see how blood flows through the heart and blood vessels; it also allows the doctor to see and measure blockages in the arteries and to measure the degree of stenosis or leakage of the heart valves. Therefore, Doppler ultrasound can be used to check for cardiovascular disease. This test allows you to view the size and structure of the heart and the direction of blood flow, but it needs to be performed by a specialized sonographer.