Which test is used to evaluate carotid artery stenosis?

• A. EKG
• B. MRI angiography
• C. Doppler ultrasound
• D. CT angiography

Answer: (C)

Measuring how blood flows through the carotid arteries with duplex Doppler ultrasound is the test of choice because it directly assesses hemodynamics and estimates the degree of narrowing without using radiation or contrast. By combining B-mode imaging with Doppler flow analysis, it visualizes the vessel lumen, detects plaques, and measures flow velocities. The speed of the blood, especially peak systolic velocity, helps gauge how severe the stenosis is, which is key for deciding management like medical therapy versus surgical intervention.

This test is safe, widely available, inexpensive, and repeatable, making it ideal for screening, diagnosis, and follow-up. Other imaging options—MRI angiography and CT angiography—provide detailed anatomy and are very useful when precise vascular anatomy is needed for planning or when ultrasound results are inconclusive, but they involve contrast and sometimes radiation. EKG doesn’t image the carotids at all, so it isn’t used to evaluate carotid stenosis.