Which of the following is an indication for carotid duplex ultrasound?

• A. Amaurosis fugax
• B. Routine lipid panel in an asymptomatic patient
• C. Headache alone
• D. Chest pain

Answer: (A)

Carotid duplex ultrasound is used when symptoms point to carotid artery disease or retinal ischemia from carotid sources. Amaurosis fugax—transient monocular vision loss—is a classic clue that the retinal area may be slipping on limited blood supply from the carotid circulation, often due to carotid plaque causing emboli or narrowing. In this setting, ultrasound of the carotids helps determine whether there is significant stenosis and guides urgent or elective management to reduce stroke risk.

Routine lipid testing in someone without symptoms, headaches alone, or chest pain do not specifically indicate carotid imaging, because they do not point to carotid artery disease.