Imaging in Acute Ischemic Stroke

Initial imaging
Patients should undergo an emergent NCHCT to evaluate for hemorrhage.

Alberta Stroke Program Early CT Score (ASPECTS)
This scale was developed to quantify the amount of damage in MCA infarction using NCHCT. However, it can also be calculated using DWI, which is referred to as DWI ASPECTS.

ASPECTS score of ≤ 7 on CT correlates with high rates of independence (mRS 0-2) after treatment with alteplase (OR 82, 95% CI 23-290).

Vessel imaging
For patients meeting criteria for possible mechanical thrombectomy, they should undergo vascular imaging (CTA or MRA) within one hour of the initial NCHCT. THIS is a Neurocritical Care Society Clinical Performance Measure.

Collateral score
This score categorizes the degree of collateral flow seen on CTA maximal intensity projection (MIP) images and correlates with clinical outcome.