Figure 3.

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) describes the spatial extent of ischemic lesions in the cortical and subcortical areas supplied by the middle cerebral artery (MCA). It can take values between 10 and 0. Ten is the normal score for intact brain parenchyma supplied by the MCA, while 0 corresponds to diffuse ischemia throughout the area supplied by the middle cerebral artery (MCA).

Cd: Caudate nucleus; L: Lentiform nucleus; IC: Internal capsule; In: Insular cortex; M1: anterior cortex supplied by MCA; M2: Lateral insular cortex; M3: Posterior cortex supplied by MCA; M4, M5, M6: Anterior, lateral, and posterior MCA territories, directly above (rostrally) M1, M2, and M3 respectively and therefore also rostral to the basal ganglia. (M1 in the context of ASPECTS does not correspond to the horizontal, proximal segment M1 of the middle cerebral artery. The fact that the names are identical are coincidental.)