A 55-year-old man with hypertension presents with a carotid bruit on examination. What is the next best step to evaluate for carotid plaques?

• A. Carotid duplex ultrasound
• B. CT head
• C. Brain MRI
• D. Echocardiography

Answer: (A)

In someone with a carotid bruit, the first step is to directly evaluate the carotid arteries for atherosclerotic plaque and determine how much the lumen is narrowed. Carotid duplex ultrasound does this noninvasively by combining imaging of the vessel wall and lumen with Doppler assessment of blood flow. The Doppler velocities correlate with the degree of stenosis, helping you classify whether the narrowing is mild, moderate, or severe. This information is essential for deciding on potential interventions, such as endarterectomy or stenting, in appropriate patients.

CT head or brain MRI look at brain tissue and prior injuries, not the extent of carotid plaque. Echocardiography assesses heart structures and potential cardiac sources of emboli, not the carotid arteries. CT or MR angiography can image the carotids but require contrast and are typically used after duplex results or when planning treatment. So the most practical, accurate initial test to evaluate for carotid plaques is carotid duplex ultrasound.