In suspected ischemic stroke, which test is most useful to determine the arterial source of the thrombus?

In suspected ischemic stroke, which test is most useful to determine the arterial source of the thrombus?

• A. Erythrocyte sedimentation rate
• B. Magnetic resonance angiography of the vertebral arteries
• C. Carotid ultrasound
• D. CT of the brain

Answer: (C)

In suspected ischemic stroke, pinpointing the arterial source of the thrombus helps guide prevention and treatment decisions, especially since carotid arteries are a common source of emboli to the brain. Carotid ultrasound (duplex imaging) is the best test for this purpose because it directly visualizes the extracranial carotid arteries, measures luminal narrowing, and assesses plaque characteristics and flow velocity. This noninvasive study quickly identifies significant carotid stenosis or unstable plaque that could be the embolic source and informs management, such as the consideration of carotid endarterectomy or other interventions when appropriate. Other options don’t target the source as effectively: magnetic resonance angiography of the vertebral arteries evaluates the posterior circulation and is useful in that domain but is not the most direct test for the common carotid source; erythrocyte sedimentation rate is a nonspecific inflammatory marker with no role in locating an embolic source; a CT of the brain shows infarct or hemorrhage but does not map the arterial source of the thrombus.

In suspected ischemic stroke, pinpointing the arterial source of the thrombus helps guide prevention and treatment decisions, especially since carotid arteries are a common source of emboli to the brain. Carotid ultrasound (duplex imaging) is the best test for this purpose because it directly visualizes the extracranial carotid arteries, measures luminal narrowing, and assesses plaque characteristics and flow velocity. This noninvasive study quickly identifies significant carotid stenosis or unstable plaque that could be the embolic source and informs management, such as the consideration of carotid endarterectomy or other interventions when appropriate.

Other options don’t target the source as effectively: magnetic resonance angiography of the vertebral arteries evaluates the posterior circulation and is useful in that domain but is not the most direct test for the common carotid source; erythrocyte sedimentation rate is a nonspecific inflammatory marker with no role in locating an embolic source; a CT of the brain shows infarct or hemorrhage but does not map the arterial source of the thrombus.