The Alberta Stroke Programme Early CT Score (ASPECTS) is a standardized CT grading system for acute anterior circulation stroke. The authors are from the University of Calgary in Alberta, Canada and the University of Texas in Houston.


Patient management and CT testing:

(1) All patients were treated with a thrombolytic agent (intravenous alteplase) within 3 hours of symptom onset.

(2) A CT scan was performed at 24 hours after the stroke onset.


Regions in subcortical structures (Figure 1, page 1671):

(1) caudate (C)

(2) lentiform (L)

(3) internal capsule (IC)


Regions in the middle cerebral artery (MCA) cortex:

(4) M1 (anterior cortex)

(5) insular cortex (I)

(6) M2 (cortex lateral to insular ribbon)

(7) M3 (posterior cortex)


Regions in the middle cerebral artery (MCA) cortical territory immediately superior to previous points, rostral to the basal ganglia:

(8) M4 (anterior cortex)

(9) M5 (lateral cortex)

(10) M6 (posterior cortex)


Findings indicating early ischemic change: one or both of the following:

(1) parenchymal hypoattenuation: a region of abnormally low attenuation of brain structures relative to attenuation of other parts of the same structures or of the contralateral hemisphere.

(2) focal brain swelling: any focal narrowing of the cerebrospinal fluid space due to compression by adjacent brain structures such as effacement of the cortical sulci or ventricular compression.



(1) initial score: 10 points

(2) subtract 1 point for each one of the regions (maximum 10) involved by early ischemic change


ASPECTS value =

= 10 - SUM(points for all 10 areas)



• minimum score: 0

• maximum score: 10

• The higher the score, the better the prognosis.

• A score of 0 indicates diffuse ischemic throughout the distribution of the territory of the affected middle cerebral artery.

• A value of > 7 identified those patients likely to be independent at 3 months after the stroke, while a value <= 7 identified patients at high risk for dependence or death.

• The risk of intracerebral hemorrhage following thrombolytic therapy was 14 times greater if the ASPECTS value was <= 7 than if it was > 7.

• The sensitivity of the ASPECTS value for functional outcome was 0.78, with a specificity of 0.96.


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