Neuroradiology · Acute ischaemic stroke · Original 10-region ASPECTS

Alberta Stroke Programme Early CT Score (ASPECTS)

A 10-point topographic NCCT score for describing the extent of early ischaemic change within the symptomatic middle cerebral artery territory.

Purpose

To quantify and communicate the extent of early ischaemic change on non-contrast CT in acute anterior-circulation stroke.

Region	Anatomical territory	Scoring rule
Starting score	Symptomatic MCA territory	Begin at 10
C	Caudate nucleus	Subtract 1 if involved
L	Lentiform nucleus	Subtract 1 if involved
IC	Internal capsule	Subtract 1 if involved
I	Insular ribbon	Subtract 1 if involved
M1	Anterior MCA cortex at the ganglionic level	Subtract 1 if involved
M2	MCA cortex lateral to the insular ribbon	Subtract 1 if involved
M3	Posterior MCA cortex at the ganglionic level	Subtract 1 if involved
M4	Anterior MCA cortex immediately superior to M1	Subtract 1 if involved
M5	Lateral MCA cortex immediately superior to M2	Subtract 1 if involved
M6	Posterior MCA cortex immediately superior to M3	Subtract 1 if involved
Final score	10 means no visible early ischaemic change; 0 means all 10 regions are involved	Lower score indicates more extensive change

How to use it

Assess the symptomatic hemisphere for definite early ischaemic change, including hypoattenuation, loss of grey–white differentiation or focal swelling.
C, L, IC, I and M1–M3 are assessed at the ganglionic level; M4–M6 are assessed superior to the ganglia.
ASPECTS is topographic rather than volumetric because its regions are not equal in size.
A treatment decision should not be based on an isolated ASPECTS threshold; integrate the score with clinical severity, vessel imaging, time from onset and current reperfusion criteria.
Posterior-circulation stroke requires the separate pc-ASPECTS system.

Common mistake

Do not confuse the M1–M6 ASPECTS cortical regions with the M1–M6 arterial segments of the middle cerebral artery.

Exam pearl

ASPECTS starts at 10 and loses one point for each involved region: four central regions—C, L, IC and I—and six cortical regions—M1 to M6.

Viva questions

What is ASPECTS?: ASPECTS is a 10-point topographic NCCT score used to quantify early ischaemic change within the symptomatic middle cerebral artery territory.
How is ASPECTS calculated?: Begin with a score of 10 and subtract one point for every ASPECTS region showing definite early ischaemic change. A score of 10 is normal, whereas 0 indicates involvement of all regions.
Which 10 regions are included in ASPECTS?: The regions are the caudate nucleus, lentiform nucleus, internal capsule, insular ribbon and six cortical regions designated M1 through M6.
How are the ganglionic and supraganglionic ASPECTS regions divided?: C, L, IC, I and M1–M3 are assessed at the ganglionic level. M4, M5 and M6 are the corresponding anterior, lateral and posterior cortical territories immediately superior to M1, M2 and M3.
Do M1–M6 in ASPECTS represent MCA arterial segments?: No. In ASPECTS, M1–M6 are predefined cortical regions and must not be confused with the angiographic arterial segments of the MCA.
Can ASPECTS alone determine eligibility for reperfusion therapy?: No. ASPECTS describes the extent of visible early ischaemic change but must be interpreted with the clinical deficit, vessel imaging, time window and current thrombolysis or thrombectomy criteria.
Can standard ASPECTS be used for posterior-circulation stroke?: No. Standard ASPECTS applies to the anterior circulation, principally the MCA territory. Posterior-circulation stroke uses the separate pc-ASPECTS system.