The Cardiovascular
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Alberta Stroke Program Early CT Score (ASPECTS)

Quantifies early ischemic change on non-contrast CT in MCA-territory stroke.

Alberta Stroke Program Early CT Score (ASPECTS)
Caudate – early ischemic change present
Lentiform nucleus – early ischemic change present
Internal capsule – early ischemic change present
Insular ribbon – early ischemic change present
M1 – anterior MCA cortex – early ischemic change present
M2 – MCA cortex lateral to insular ribbon – early ischemic change present
M3 – posterior MCA cortex – early ischemic change present
M4 – anterior MCA territory, superior to M1 – early ischemic change present
M5 – lateral MCA territory, superior to M2 – early ischemic change present
M6 – posterior MCA territory, superior to M3 – early ischemic change present
Result10 points

Limited early ischemic change; CT appearance not a contraindication to reperfusion therapy on ASPECTS grounds alone.

Regions with early ischemic change
0

When to use

  • Grading the extent of early ischemic change on non-contrast CT in acute anterior-circulation (MCA-territory) ischemic stroke.
  • Supporting patient selection for IV thrombolysis or mechanical thrombectomy alongside clinical and other imaging criteria.

Formula

ASPECTS = 10 minus the number of the 10 defined MCA regions (caudate, lentiform nucleus, internal capsule, insular ribbon, and cortical regions M1-M6) that show early ischemic change on non-contrast CT. Score ranges from 10 (no early ischemic change) to 0 (diffuse involvement of the entire MCA territory).

Pearls and pitfalls

  • Best read on the two standardized axial CT levels: the ganglionic level (caudate, lentiform, internal capsule, insula, M1-M3) and the supraganglionic level (M4-M6).
  • A subcortical region (caudate, lentiform, internal capsule) counts as involved even with subtle hypoattenuation or loss of grey-white differentiation.

References

  1. 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. Lancet. 2000;355(9216):1670-1674.