Which imaging approach is prioritized to identify large vessel occlusions and guide reperfusion decisions?

• A. X-ray skull series.
• B. CT angiography combined with non-contrast CT.
• C. Only MRI without CT.
• D. Ultrasound of carotids.

Answer: (B)

Identifying a large vessel occlusion and guiding reperfusion relies on rapidly imaging both the brain tissue and the blood vessels. A non-contrast CT is used first to rule out intracranial hemorrhage and to provide a baseline view of early ischemic changes, which is essential before any reperfusion therapy. Adding CT angiography then visualizes the cerebral arteries, showing whether a clot is present, its exact location, and the status of collateral flow. This combination gives the critical information needed to decide if a patient is a candidate for intravenous thrombolysis and, importantly, for mechanical thrombectomy when a large vessel occlusion is present.

Other imaging options don’t provide this same quick, combined assessment. X-ray skull series lacks sensitivity for acute ischemia and cannot reliably identify large-vessel occlusions. Ultrasound of the carotids mostly assesses neck vessels and doesn’t reveal intracranial occlusions or the overall brain perfusion status. MRI without CT can be slower and less practical in the acute triage setting, where rapid decisions are crucial.