Doppler Ultrasound: Using the Doppler Effect for Medical Diagnosis

When most people hear the term "Doppler effect," they think of how many meteorologists use Doppler to predict weather patterns. However, Doppler can also be used for medical diagnosis in the form of a Doppler ultrasound. In a normal ultrasound, a technician applies a gel that acts as a conductor for sound waves to the patient's skin. A transducer is moved over the area being tested and sound waves are used to create pictures of organs and other tissues. The Doppler effect is used to measure the "change in sound waves reflected by a moving object" (Mayo Clinic), so it can be used during ultrasounds to diagnose several medical problems.

Because Doppler is used to measure changes in sound waves, it is used to diagnose conditions related to circulation and blood flow. The Doppler ultrasound can actually measure how fast or slow blood is moving, which can indicate a circulatory problem. Blood clots can be found using Doppler ultrasound because the ultrasound will be able to detect slower blood flow or a lack of blood flow where the clot is located. Doppler ultrasound can also be used to identify narrowed arteries, plaque buildup in the blood vessels, or blocked arteries. Found early, many of these conditions can be treated before they become more serious.

The Doppler ultrasound may be done on the neck or on the extremities of the body, depending on what symptoms the patient is experiencing. This test is performed exactly like a regular ultrasound. The technician applies gel to the area being tested, a transducer is moved over the gelled area, and the ultrasound machine interprets the sound waves and creates pictures of what is happening inside the body.

The main benefit of Doppler ultrasound is that it is less invasive than other procedures used to identify these types of medical problems. The ultrasound is perform on the outside of the body and is not painful. Some discomfort may be experienced as the transducer is used, but it is often minimal. Because the ultrasound is not invasive, there are fewer risks to using it as a diagnostic test and many patients are able to have serious conditions detected without having to spend extensive time in the hospital.