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Zorluk: Çok zorInterpreting Imaging Results

A 72-year-old man is brought to the emergency department by his family at 08:00 after they found him in bed with dense right-sided hemiplegia and severe global aphasia. He was last known to be neurologically at baseline when he went to sleep at 22:00 the previous night. Initial vital signs reveal a blood pressure of 165/90 mm Hg and a heart rate of 88/min. The acute stroke team is activated to evaluate the patient for potential endovascular reperfusion therapy.

Arrange the following neuroimaging modalities and their corresponding primary interpretive objectives in the correct chronological sequence required to definitively qualify this patient for extended-window mechanical thrombectomy.

  1. 1Non-contrast computed tomography (NCCT) of the head to exclude acute intracranial hemorrhage and estimate early ischemic changes.
  2. 2Computed tomography angiography (CTA) of the head and neck to confirm the presence of a proximal large vessel occlusion.
  3. 3Computed tomography perfusion (CTP) imaging to quantify the infarct core volume and identify salvageable ischemic penumbra.
  4. 4Digital subtraction angiography (DSA) to map the precise cerebrovascular anatomy and guide the endovascular device.

Cevap

The correct sequence of imaging evaluation for a wake-up stroke being considered for extended-window mechanical thrombectomy is: Non-contrast CT (NCCT), followed by CT Angiography (CTA), then CT Perfusion (CTP), and finally Digital Subtraction Angiography (DSA).
The correct chronological interpretation sequence maximizes patient safety and adheres to established stroke protocols for the extended window (DAWN/DEFUSE-3 criteria). NCCT must be interpreted first to rule out bleeding before administering any contrast or considering reperfusion. CTA immediately follows to confirm an actionable occlusion. Because the patient is outside the standard 6-hour window (last known well was 10 hours prior), CTP is mandatory to prove a target mismatch (salvageable penumbra significantly larger than irreversible core) before proceeding to invasive DSA for the actual thrombectomy procedure.

Adım Adım Çözüm

1
Obtain and interpret Non-contrast computed tomography (NCCT)
Excludes intracranial hemorrhage and provides an ASPECTS score.
Administering intravenous contrast or proceeding with any reperfusion therapy is absolutely contraindicated until active bleeding is ruled out.
2
Obtain and interpret Computed tomography angiography (CTA)
Identifies the presence of a proximal large vessel occlusion (LVO).
Endovascular therapy is only indicated if there is a targetable clot in a major cerebral vessel (e.g., ICA or M1 segment of the MCA).
3
Obtain and interpret Computed tomography perfusion (CTP)
Determines the core-to-penumbra mismatch volume.
For 'wake-up' strokes or those presenting in the 6-24 hour window, establishing that salvageable brain tissue still exists is mandatory to prevent futile recanalization and reperfusion injury.
4
Perform Digital subtraction angiography (DSA)
Provides real-time dynamic vascular mapping.
Used immediately during the intra-arterial procedure to navigate the catheter and guide the stent retriever or aspiration device to the clot.

Anahtar Kavram

Evaluation of a wake-up stroke for extended-window mechanical thrombectomy requires a strict sequential imaging protocol: exclude hemorrhage (NCCT), confirm a target occlusion (CTA), prove salvageable tissue exists (CTP), and therapeutically guide intervention (DSA).
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Interpreting Imaging Results

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