A 72-year-old man is brought to the emergency department after his family found him with profound right-sided hemiparesis, right facial droop, and severe global aphasia. He was last known to be in his usual state of health 9 hours ago when he went to sleep. Vital signs show a blood pressure of 185/100 mm Hg and a pulse of 88/min that is irregularly irregular. Point-of-care blood glucose is 110 mg/dL. The facility is a comprehensive stroke center. Arrange the following neuroimaging modalities in the most appropriate chronological sequence for guiding the acute management of this patient's condition.
- 1Non-contrast computed tomography (CT) of the head
- 2Computed tomography angiography (CTA) of the head and neck
- 3Computed tomography (CT) perfusion imaging
- 4Digital subtraction angiography (DSA)
Answer
The correct sequence is: Non-contrast CT of the head, followed by CTA of the head and neck, followed by CT perfusion imaging, and finally Digital subtraction angiography (DSA).
In the evaluation of acute stroke, especially outside the standard 6-hour window for endovascular therapy, the stepwise imaging approach prioritizes safety and precise patient selection. Non-contrast CT is always first to rule out hemorrhage. Once ruled out, CTA is used to identify a target occlusion. Because the time since last known normal is 9 hours, CT perfusion is then strictly required to prove there is a favorable mismatch (salvageable penumbra) per the DAWN or DEFUSE 3 criteria. Finally, if the patient meets all clinical and imaging criteria, DSA is performed as the definitive therapeutic modality for mechanical thrombectomy.
Step-by-Step Solution
Key Concept
Neuroimaging sequence for acute ischemic stroke in the extended time window