ASPECTS Score Calculator (Stroke CT)

Alberta Stroke Program Early CT Score (ASPECTS) for early MCA ischemic change (0–10).

For educational and clinical reference. Not a substitute for medical judgment. See the medical disclaimer.

Caudate (C)

Lentiform nucleus (L)

Internal capsule (IC)

Insular ribbon (I)

M1 — anterior MCA cortex

M2 — MCA cortex lateral to insula

M3 — posterior MCA cortex

M4 — anterior MCA, superior to M1

M5 — lateral MCA, superior to M2

M6 — posterior MCA, superior to M3

Score

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Interpretation

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References

Barber PA, Demchuk AM, Zhang J, Buchan AM. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy (ASPECTS). Lancet. 2000;355(9216):1670-1674.

How to use

For each of the 10 MCA regions, mark whether early ischemic change is present.
The ASPECTS (10 minus affected regions) and interpretation update instantly.
Use with NIHSS and vascular imaging for acute reperfusion decisions.

Frequently asked questions

What is the ASPECTS score?

The Alberta Stroke Program Early CT Score is a 10-point quantitative topographic score of early ischemic change in the middle cerebral artery territory on non-contrast CT.

How is ASPECTS calculated?

Start from 10 and subtract 1 point for each of the 10 defined MCA regions showing early ischemic change. A normal scan scores 10.

What ASPECTS supports thrombectomy?

In most trials and guidelines, ASPECTS ≥ 6 favours mechanical thrombectomy in the early window; lower scores indicate a larger established core and less benefit (evolving with imaging selection).

Why does a low ASPECTS matter?

A low score reflects a larger infarct core, predicting worse functional recovery and a higher risk of symptomatic intracerebral hemorrhage after reperfusion.

Last updated June 28, 2026