Radiology · Year 4 · from Radiology

Case 2: Acute Ischemic Stroke - Large Vessel Occlusion

Patient Demographics

  • Age: 64 years
  • Sex: Female

Chief Complaint

Sudden onset right-sided weakness and difficulty speaking

Presenting Symptoms

The patient was in her normal state of health when her husband noticed she suddenly developed slurred speech and her right arm "went limp" at 10:15 AM. EMS was activated immediately. She arrived at the stroke center at 10:52 AM (last known well: 37 minutes ago). She has a history of hypertension and hyperlipidemia. She takes amlodipine and atorvastatin.

Physical Exam Findings

  • Vital Signs: BP 178/102 mmHg, HR 88 bpm (regular), glucose 142 mg/dL
  • NIHSS Score: 18
  • Level of consciousness: Alert (0)
  • Gaze: Forced left gaze deviation (2)
  • Visual fields: Right hemianopia (2)
  • Facial palsy: Right lower facial weakness (2)
  • Motor arm: Right arm no movement (4)
  • Motor leg: Right leg minimal movement (3)
  • Ataxia: Unable to assess right side
  • Sensory: Moderate deficit right side (1)
  • Language: Moderate aphasia (2)
  • Dysarthria: Moderate (1)
  • Neglect: Visual and sensory neglect (1)

Imaging Findings and Interpretation

Non-Contrast Head CT (Door-to-CT: 12 minutes):

  • Hyperdense MCA Sign: Linear hyperdensity in the left M1 segment of the middle cerebral artery, representing acute thrombus
  • Early Ischemic Changes: Subtle loss of gray-white differentiation in the left insular cortex (insular ribbon sign)
  • ASPECTS Score: 9 (1 point deducted for insular involvement)
  • No Hemorrhage: No evidence of intracranial hemorrhage
  • Candidate for IV thrombolysis

CT Angiography (CTA):

  • Left M1 Occlusion: Complete occlusion of the left middle cerebral artery at the M1 segment
  • Thrombus Length: Approximately 8 mm
  • Collaterals: Good pial collateral filling to the left MCA territory via ACA and PCA
  • Proximal Vessels: Patent left ICA without significant stenosis
  • Right Circulation: Patent

CT Perfusion:

  • Core (CBF <30%): 15 mL in left MCA territory
  • Total Hypoperfused (Tmax >6s): 120 mL
  • Mismatch Volume: 105 mL
  • Mismatch Ratio: 8:1 (significant penumbra present)

Interpretation: Large vessel occlusion with small ischemic core and large penumbra - excellent candidate for mechanical thrombectomy.

Diagnosis

Acute ischemic stroke, left MCA territory, due to left M1 occlusion; eligible for IV thrombolysis and mechanical thrombectomy

Management

  1. IV Alteplase (tPA):
  • Door-to-needle time: 28 minutes
  • 0.9 mg/kg IV (10% bolus, remainder over 60 minutes)
  • Administered while preparing for thrombectomy ("drip and ship" not needed as already at comprehensive stroke center)
  1. Mechanical Thrombectomy:
  • Groin puncture at 11:45 AM
  • Aspiration thrombectomy with stent retriever
  • TICI 3 recanalization achieved (complete reperfusion)
  • Puncture-to-recanalization: 32 minutes
  1. Post-Procedure:
  • 24-hour NIHSS: 4 (significant improvement from 18)
  • Post-thrombectomy CT: Small left insular infarct, no hemorrhagic transformation
  • Stroke workup: Echo, telemetry, lipid panel, HbA1c
  • Started on high-intensity statin and dual antiplatelet therapy
  • Source identified: Paroxysmal atrial fibrillation on telemetry
  • Transitioned to anticoagulation for secondary prevention

Radiological Image

Image Description: CT perfusion imaging in acute ischemic stroke demonstrating the mismatch between the small ischemic core (irreversibly damaged tissue shown in red/dark) and the larger area of hypoperfusion (penumbra - potentially salvageable tissue). This mismatch identifies patients who may benefit from reperfusion therapy.

Source: Radiopaedia - Educational reference on stroke imaging URL: https://radiopaedia.org/articles/ct-perfusion-in-acute-stroke License: Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported

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