Doppler ultrasonography is a noninvasive test that evaluates which of the following?

• A. Non-invasive test that evaluates blood flow in major veins, arteries, and cerebrovascular system.
• B. Examines electrical activity of the heart.
• C. Produces cross-sectional images using X-rays.
• D. Measures lung diffusion.

Answer: (A)

Doppler ultrasonography uses the Doppler effect to detect movement of blood within vessels. By emitting sound waves and listening for frequency shifts caused by moving red blood cells, it reveals the direction and speed of blood flow. This makes it ideal for evaluating flow in major arteries and veins, including the cerebrovascular system, to detect issues like stenosis, occlusions, or abnormal flow patterns. It’s noninvasive, real-time, and free of ionizing radiation, which is why it’s used to assess vascular health. It does not measure the heart’s electrical activity, produce cross-sectional X-ray images, or assess lung diffusion.