Calc Function

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    Chief Complaint


    Organ System


    Patent Pending

    Alberta Stroke Program Early CT Score (ASPECTS)

    Determines MCA stroke severity using available CT data.


    To compute the ASPECTS, 1 point is subtracted from 10 for any evidence of early ischemic change for each of the defined regions.
    When to Use
    Why Use

    Patients in the first minutes and hours of a stroke that appears clinically to be affecting the middle cerebral artery.

    • The ASPECTS quantifies CT changes in early middle cerebral artery stroke.
      • More early changes seen on CT suggest a poorer outcome from stroke.
    • Those with a score ≥8 have a better chance for an independent outcome.

    Points to keep in mind:

    • The score does not consistently predict treatment response or intracranial hemorrhage, or offer nuanced prognostic information.
    • ASPECT studies are universally on patients treated with or eligible for stroke reperfusion therapy (tPA), which many strokes patients do not qualify for.

    Identifying patients with a greater likelihood of poor functional outcome (a score <8) may be helpful in the early stages of care, supporting transfer or therapy decisions.

    Subcortical Structures
    MCA Cortex


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    Next Steps
    Creator Insights


    Using the traditional cutoff (<8 vs ≥8) as a rough estimate for predicting independence can inform decisions. Like the 1/3rd score, the ASPECTS points out that early CT changes in stroke may be a harbinger.


    We are unaware of validated management algorithms using the ASPECTS.

    Critical Actions

    The ASPECTS relies on subtle CT findings and thus requires an experienced radiologist. Its only validated use is as a binary (<8 vs ≥8) variable for general outcome prediction in those eligible for reperfusion therapy.


    To compute the ASPECTS, 1 point is subtracted from 10 for any evidence of early ischemic change for each of the defined regions.

    • A normal CT scan receives an ASPECTS of 10 points.
    • An ASPECTS of ≤ 7 points highly correlates with negative functional outcome, determined by Modified Rankin Scale (mRS).
    • An ASPECTS of 0 indicates diffuse involvement throughout the MCA territory.
    • Subcortical structures are allotted 3 points (C, L, and IC). MCA cortex is allotted 7 points (insular cortex, M1, M2, M3, M4, M5 and M6).


    • C - Caudate
    • I - Insularribbon
    • IC - Internal Capsule
    • L - Lentiform nucleus
    • M1 - Anterior MCA cortex
    • M2 - MCA cortex lateral to the insular ribbon
    • M3 - Posterior MCA cortex
    • M4*
    • M5*
    • M6*

    *Anterior, lateral and posterior MCA territories immediately superior to M1, M2 and M3, rostral to basal ganglia.

    Facts & Figures

    • The ASPECTS is determined from evaluation of two standardized regions of the MCA territory: the basal ganglia level, where the thalamus, basal ganglia, and caudate are visible, and the supraganglionic level, which includes the corona radiata and centrum semiovale.
    • All cuts with basal ganglionic or supraganglionic structures visible are required to determine if an area is involved. The abnormality should be visible on at least two consecutive cuts to ensure that it is truly abnormal rather than a volume averaging effect.

    Two brain slices at ganglionic and supraganglionic levels


    Dr. Phillip A. Barber

    About the Creator

    Phillip A. Barber, MD, FRCPC, is an associate professor of neurology at the University of Calgary and is also the co-director of the Stroke Prevention Clinic. He has been awarded the New Investigator Award by the CIHR, Heart and Stroke Foundation of Canada, and the Alberta Heritage Foundation of Medical Research. Dr. Barber's primary research revolves around dementia, infarct maturation and stroke.

    To view Dr. Phillip A. Barber's publications, visit PubMed

    About the Creator
    Dr. Phillip A. Barber