American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended imaging technique to visualize occlusion after thrombolysis for acute ischemic stroke?

1. Magnetic Resonance Imaging (MRI)

2. X-ray examination

3. CT angiography

4. Ultrasound

The correct answer is: CT angiography

The recommended imaging technique to visualize occlusion after thrombolysis for acute ischemic stroke is CT angiography. This method is favored because it provides rapid and detailed visualization of the cerebral vasculature, allowing clinicians to assess whether there has been successful recanalization of occluded arteries or if there is persistent occlusion despite treatment. CT angiography can be performed quickly, which is critical in the acute setting of a stroke, enabling timely decision-making regarding further intervention or monitoring. It is particularly useful for identifying large vessel occlusions, which are often the primary targets of thrombolytic therapy. In contrast, while magnetic resonance imaging can visualize brain tissue and ischemic changes, it is not as readily available in acute settings and is less effective for real-time assessment of vascular occlusion. X-ray examination lacks the sensitivity to evaluate vascular structures effectively, making it unsuitable for this purpose. Ultrasound may be useful in specific scenarios, such as assessing carotid arteries, but it does not provide a comprehensive view of the intracranial vasculature needed after thrombolytic therapy.