The Alberta Stroke Program Early CT (ASPECT) Score was developed as a reproducible grading system to assess early ischemic changes on pretreatment CT scans.
Within 3 hours of MCA stroke onset, ASPECT Score correlates with the severity of NIHSS and functional outcome.
- ASPECT Score of 0: Diffuse involvement throughout the MCA territory
- ASPECT Score of ≤ 7: Poor functional outcome and symptomatic intracerebral hemorrhage
- ASPECT Score 8-10: Greater benefit from IV thrombolysis
- ASPECT Score of 10: Normal
|Good||5||Compared to asymptomatic contralateral hemisphere, there is no delay and normal or increased prominence of peripheral vessels/ normal extent within the occluded arteries territory within the symptomatic hemisphere.|
|4||Compared to asymptomatic contralateral hemisphere there is a delay of one phase in filling in of peripheral vessels but prominence and extent is the same.|
|Intermediate||3||Compared to asymptomatic contralateral hemisphere there is a delay of two phases in filling in of peripheral vessels but prominence and extent is the same or there is a one phase delay and decreased prominence (thinner vessels) / reduced number of vessels in some part of the territory occluded.|
|2||Compared to asymptomatic contralateral hemisphere there is a delay of two phases in filling in of peripheral vessels and decreased prominence and extent or a one-phase delay and some regions with no vessels in some part of the territory occluded.|
|Poor||1||Compared to asymptomatic contralateral hemisphere there are just a few vessels visible in any phase within the occluded vascular territory.|
|0||Compared to asymptomatic contralateral hemisphere there are no vessels visible in any phase within the occluded vascular territory.|
Collaterals are measured on muli-phase CTA by comparing backfilling arteries beyond the blocked artery to similar arteries in the opposite unaffected hemisphere. Vascular enhancement distal to occlusion is scored in anterior and posterior MCA territories as. No or minimal collaterals in a region greater than 50% of the MCA territory when compared to pial filling on the contralateral side can also be considered as poor collaterals.
Pexman JH, Barber PA, Hill MD, Sevick RJ, Demchuk AM, Hudon ME, Hu WY, Buchan AM. Use of the Alberta Stroke Program Early CT Score (ASPECTS) for assessing CT scans in patients with acute stroke. AJNR Am J Neuroradiol. 2001 Sep;22(8):1534-42.