A Doppler ultrasound is a specialized ultrasound imaging test that uses sound waves to assess blood flow through your blood vessels. It can examine blood flow in various areas of your body, including organs, and the neck, arms, and legs.

This test evaluates both arteries (vessels that carry oxygen-rich blood from your heart and lungs to the body) and veins (vessels that return blood from the body to the heart and lungs for reoxygenation).

Doppler ultrasound works by bouncing sound waves off red blood cells moving through your blood vessels. The ultrasound device then measures the echoes that return from these cells. Red blood cells moving toward the sound waves create different echoes compared to those moving away from them. This phenomenon is known as the Doppler effect, named after the scientist who discovered it.

Doppler ultrasound can help detect conditions affecting blood vessels, such as narrowed arteries, blood clots, or other abnormalities, by showing how the amount, speed, and direction of blood flow vary in different parts of the body.

There are several types of Doppler ultrasound tests, each designed to provide specific information:

• Color Doppler: This test uses a computer to convert sound wave measurements into colors, indicating the speed and direction of blood flow.

• Power Doppler: A more advanced form of color Doppler, this test can detect smaller blood vessels and slower blood flow, but it doesn't show the direction of flow.

• Spectral Doppler: This test presents blood flow information in a graph, indicating how much of a blood vessel is blocked. It comes in two types:

  • Pulsed Wave Doppler: Shows varying blood flow speeds but cannot capture high-speed blood flow.
  • Continuous Wave Doppler: Captures fast blood flow but doesn't pinpoint the exact location in the vessel.

• Duplex Doppler: This combines standard ultrasound images of blood flow with a graph, similar to spectral Doppler, to provide a more detailed view of blood flow.