Linking To And Excerpting From Radiopaedia’s “Alberta stroke programme early CT score (ASPECTS)”

Posted on July 14, 2026 by Tom Wade MD

Today. I review, link to, and excerpt from Radiopaedia‘s “Alberta stroke programme early CT score (ASPECTS)”.* Last revised by Henry Knipe on 2 Mar 2026.

*Citation:Sair H, Khalighinejad P, Hacking C, et al. Alberta stroke programme early CT score (ASPECTS). Reference article, Radiopaedia.org (Accessed on 13 Jul 2026) https://doi.org/10.53347/rID-4936
DOI:https://doi.org/10.53347/rID-4936
Permalink:https://radiopaedia.org/articles/alberta-stroke-programme-early-ct-score-aspects
rID:Article (rID 4936, “Alberta stroke programme early CT score (ASPECTS)”)

All that follows is from the above resource.

The Alberta stroke program early CT score (ASPECTS) 1 is a 10-point quantitative topographic CT score used for patients with middle cerebral artery (MCA) stroke. It has also been adjusted for the posterior circulation (see below).

An ASPECTS score ≤7 predicts a worse functional outcome at 3 months as well as symptomatic hemorrhage. According to the study by Aviv et al., patients with an ASPECTS score <8 treated with thrombolysis did not have a good clinical outcome 3.

Segmental estimation of the middle cerebral artery (MCA) vascular territory is made, and 1 point is deducted from the initial score of 10 for every region involved:

  • caudate
  • putamen
  • internal capsule
  • insular cortex
  • 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: “anterior MCA territory immediately superior to M1”
  • M5: “lateral MCA territory immediately superior to M2”
  • M6: “posterior MCA territory immediately superior to M3”

Important points:

  • the initial paper 1 specifically referred to the internal capsule only involving the posterior limb, however, subsequent articles indicate any portion of the internal capsule may be included
  • M1 to M3 are at the level of the basal ganglia
  • M4 to M6 are at the level of the ventricles immediately above the basal ganglia
  • M1 to M4 are not to be confused with the anatomic segments of the middle cerebral artery

Variations of the ASPECT scoring system have been described for use in the posterior circulation and referred to as pc-ASPECTS 5.

As is the case for the anterior circulation, the pc-ASPECTS is a 10 point scale, where points are lost for each region affected. Unlike ASPECTS, the pons and the midbrain are worth 2 points each (regardless of whether or not the changes are bilateral; any involvement of the pons, for example, deducted 2 points).

  • thalami (1 point each)
  • occipital lobes (1 point each)
  • midbrain (2 points)
  • pons (2 points)
  • cerebellar hemispheres (1 point each)

References

  • 1. Barber P, Demchuk A, Zhang J, Buchan A. Validity and Reliability of a Quantitative Computed Tomography Score in Predicting Outcome of Hyperacute Stroke Before Thrombolytic Therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet. 2000;355(9216):1670-4. doi:10.1016/s0140-6736(00)02237-6 – Pubmed
  • 2. Pexman J, Barber P, Hill M et al. Use of the Alberta Stroke Program Early CT Score (ASPECTS) for Assessing CT Scans in Patients with Acute Stroke. AJNR Am J Neuroradiol. 2001;22(8):1534-42. PMC7974585 – Pubmed
  • 3. Aviv R, Mandelcorn J, Chakraborty S et al. Alberta Stroke Program Early CT Scoring of CT Perfusion in Early Stroke Visualization and Assessment. AJNR Am J Neuroradiol. 2007;28(10):1975-80. doi:10.3174/ajnr.A0689 – Pubmed
  • 4. Puetz V, Dzialowski I, Hill M, Demchuk A. The Alberta Stroke Program Early CT Score in Clinical Practice: What Have We Learned? Int J Stroke. 2009;4(5):354-64. doi:10.1111/j.1747-4949.2009.00337.x – Pubmed
  • 5. Puetz V, Sylaja P, Coutts S et al. Extent of Hypoattenuation on CT Angiography Source Images Predicts Functional Outcome in Patients with Basilar Artery Occlusion. Stroke. 2008;39(9):2485-90. doi:10.1161/STROKEAHA.107.511162 – Pubmed

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