Alberta Stroke Program Early CT Score

Created 02.09.2019 , last update 22.03.2021

  • the Alberta Stroke Program Early CT Score (ASPECTS) is used to standardize and increase the reliability of early signs of ischemia detection 
  • it can be assessed on:
    • non-contrast CT (NCCT) – adjustment of width/level can be helpful   Effect of window adjustment on NCCT
    • CT perfusion (CTP)  [Aviv, 2007]
    • CTA source images (CTA-SI)   [Puetz, 2009]
  • ASPECTS evaluates primarily the MCA territory
  • PC-ASPECTS evaluates changes specifically in the posterior circulation 
  • there are commercial programs available, evaluating ASPECTS automatically  (e.g. BRAINOMIX)   Brainomix - ASPECTS 6 BRAINOMIX - automated evaluation of early ischemic changes o NCCT
MCA territory
  • a 10-point quantitative CT scan score used for patients with middle cerebral artery stroke
  • 10 points are normal; 1 point is deducted from the initial score of 10 for every region with early signs of ischemia
    • C – caudate nucleus
    • L – lentiform nucleus
    • IC – internal capsule (any portion)
    • I – the insular cortex
    • M1-3 are at the level of the basal ganglia
      • M1 – anterior MCA cortex corresponding to the frontal operculum
      • M2 – MCA cortex lateral to insular ribbon corresponding to the anterior temporal lobe
      • M3 – posterior MCA cortex corresponding to the posterior temporal lobe
    • M4-5 are above the basal ganglia, at the level of the ventricles
      • M4 – anterior MCA territory immediately superior to M1
      • M5 – lateral MCA territory immediately superior to M2
      • M6 – posterior MCA territory immediately superior to M3
  • ASPECTS is a valuable technique for the evaluation of the prognosis in acute ischemic stroke (thresholds are slightly different for NCCT a CTP)
    • generally, patients with high ASPECTS values are more likely to attain favorable outcomes
    • an NCCT ASPECTS score ≤ of 7 predicts a worse functional outcome at three months  [Esmael, 2021]
    • patients with CTP ASPECTS score < 8 treated with thrombolysis mostly did not achieve a good clinical outcome  [Aviv, 2007]
Ischemic changes in regions I, L and M5
Ischemic changes in regions I, M2 and M5
ASPECTS 8 - hypodensity in C and L
Posterior circulation

PC-ASPECTS (The posterior circulation Acute Stroke Prognosis Early CT score)

  • normal brain scores 10 points, points are lost for each affected region
    • thalami (1 point each)
    • occipital lobes (1 point each)
    • midbrain (2 points – uni- and bilateral)
    • pons (2 points – uni- and bilateral)
    • cerebellar hemispheres (1 point each)
  • pc-ASPECTS < 8 points ⇒ poor prognosis   [Puetz, 2009]
pc-ASPECT score predicts prognosis [Puetz, 2009]
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