Alberta stroke programme early CT score (ASPECTS)

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

Scoring system

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

Clinical use

An ASPECTS score less than or equal to 7 predicts a worse functional outcome at 3 months as well as symptomatic hemorrhage.

According to the study performed by R I Aviv et al., patients with ASPECTS score less than 8 treated with thrombolysis did not have a good clinical outcome ³.

Posterior circulation

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)