system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
An 81-year-old man comes to the emergency department because of left-sided visual loss that started 1 hour ago. He describes initially seeing jagged edges, which was followed by abrupt, complete loss of central vision in the left eye. He has hypertension and type 2 diabetes mellitus. Blood pressure is 145/89 mm Hg. Neurologic examination shows no abnormalities. A photograph of the fundoscopic findings is shown. Which of the following tests is most likely to confirm this patient's underlying condition?
assistant
Carotid artery duplex ultrasonography