In the workup of TIA, which study is most helpful to evaluate carotid stenosis?

• A. Carotid duplex ultrasound
• B. Echocardiography
• C. CT angiography
• D. MRI brain

Answer: (C)

When evaluating a TIA for carotid stenosis, you want imaging that accurately shows both the degree of narrowing and the anatomy of the carotid arteries, so you can decide on treatment.

Carotid duplex ultrasound is a useful initial screen because it’s noninvasive and readily available, but its accuracy can be limited by patient factors and it mainly assesses extracranial carotids without reliably detailing intracranial vessels or providing precise plaque morphology.

CT angiography uses contrast-enhanced CT to visualize the carotid arteries from the neck into the skull, giving a precise measurement of stenosis, clear anatomy, and information about plaque characteristics. This comprehensive view is especially helpful for planning interventions such as carotid endarterectomy or stenting, and it can assess both extracranial and intracranial circulation in one study.

MRI brain shows the extent and location of infarction but does not quantify carotid narrowing as well as CT angiography. Echocardiography looks at cardiac sources of emboli rather than carotid stenosis.

So CT angiography is the best single test for evaluating carotid stenosis in the workup of a TI.