American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the best imaging technique to detect cerebral vasospasm?

1. CT angiography of the brain

2. Standard MRI

3. X-ray of the skull

4. Ultrasound of the carotid arteries

The correct answer is: CT angiography of the brain

The best imaging technique to detect cerebral vasospasm is CT angiography of the brain. This method provides a detailed view of the blood vessels in the brain, allowing for the assessment of blood flow and identifying any areas where the vessels may be narrowed or constricted, characteristic of vasospasm. CT angiography is particularly advantageous because it combines the structural insights of a CT scan with the functional information of angiography, making it excellent for visualizing vascular abnormalities in a timely manner, especially in acute settings. This is crucial in the context of conditions like subarachnoid hemorrhage, where vasospasm can develop and lead to serious complications. Other imaging modalities, such as standard MRI, may be effective for visualizing soft tissue characteristics and detecting other types of brain injury but are less specific for immediate assessment of blood vessel patency in the scenario of vasospasm. X-ray of the skull does not provide useful information about cerebral vessels, and ultrasound of the carotid arteries primarily evaluates the extracranial circulation and is not as effective for assessing intra-cranial vasospasms.