What is the primary purpose of Doppler ultrasound?

The primary purpose of Doppler ultrasound is to measure blood flow and velocity. This technique utilizes the Doppler effect, which is the change in frequency or wavelength of sound waves as they reflect off moving objects, such as red blood cells. By analyzing the frequency shifts of the ultrasound waves after they bounce off these moving cells, clinicians can determine how fast the blood is flowing through various vessels, as well as assess the direction of that flow.

In clinical practice, Doppler ultrasound is essential for diagnosing vascular conditions, understanding hemodynamics in the heart, and monitoring blood flow in various organs. It helps in evaluating conditions like arterial blockages, venous thrombosis, and congenital heart defects. This functionality is distinct from techniques used in other imaging methods, which focus on creating visual images of structures rather than measuring movement.

The other options focus on aspects of ultrasound that do not relate to blood flow. Creating images of soft tissues pertains to traditional ultrasound imaging techniques, assessing tissue density is related to elastography or specific imaging protocols like CT or MRI, and monitoring the electrical activity of the heart relates to electrocardiography. Each of these has different applications that do not involve the Doppler effect.