ASPECTS score: Alberta Stroke Program Early CT Score (Barber 2000)

The ASPECTS score, short for Alberta Stroke Program Early CT Score, rates early ischaemic change on a non-contrast CT in the territory of the middle cerebral artery (MCA). It starts at 10 and loses 1 point for each of ten set regions that shows early change, so the ASPECTS score runs from 10 (no regions involved) down to 0 (all involved). Magent's calculator takes a yes/no for each region and returns the total.

Not a medical device. Not a diagnosis or dosing recommendation.

Use this calculator via API

Neurology calculators
Barber PA et al. · 2000
The ASPECTS score formula
Worked examples
Frequently asked questions

What is the ASPECTS score?

Barber, Demchuk, Zhang and Buchan in Calgary wanted a simple, repeatable way to describe how much of the MCA territory already looked affected on an early CT. They divided the territory into ten regions on two axial levels and counted the regions with early ischaemic change.

Early ischaemic change here means focal swelling or reduced density of brain tissue in a region. A lower ASPECTS means more regions are affected.

This calculator scores the original MCA-territory ASPECTS. The separate posterior-circulation version, pc-ASPECTS, uses other regions.

The ASPECTS score formula

ASPECTS = 10 - number of regions with early ischaemic change

Deep regions:      C (caudate), L (lentiform), IC (internal capsule),
                   I (insular ribbon)
Cortical regions:  M1, M2, M3 (level of the basal ganglia)
                   M4, M5, M6 (just above, over M1, M2, M3)

score 0 to 10

Exact expression the calculator uses:

ASPECTS = 10 - (C + L + IC + I + M1 + M2 + M3 + M4 + M5 + M6); 1 point subtracted for caller-assigned early ischemic change (focal swelling or parenchymal hypoattenuation) in each published MCA-territory region; C=caudate, L=lentiform, IC=internal capsule, I=insular ribbon, M1=anterior MCA cortex, M2=MCA cortex lateral to insular ribbon, M3=posterior MCA cortex, M4/M5/M6=anterior/lateral/posterior MCA territories immediately superior to M1/M2/M3, rostral to basal ganglia; Barber 2000; score 0-10; not posterior-circulation pc-ASPECTS

Inputs

Input	Region
`caudate`	C, caudate
`lentiform`	L, lentiform nucleus
`internal_capsule`	IC, internal capsule
`insular_ribbon`	I, insular ribbon
`m1`	Anterior MCA cortex
`m2`	MCA cortex lateral to the insular ribbon
`m3`	Posterior MCA cortex
`m4`	Anterior MCA territory above M1
`m5`	Lateral MCA territory above M2
`m6`	Posterior MCA territory above M3

Each is a yes/no for early ischaemic change, set by whoever reads the scan. The calculator doesn't look at images.

How the calculation works

Read the scan. For each of the ten regions, decide whether early ischaemic change is present.
Count. Add up the regions marked yes.
Subtract. ASPECTS is 10 minus that count.

Every region counts the same, whether it's a small deep structure or a large cortical area.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: no region involved

All ten regions no.
ASPECTS 10.

Example 2: insular ribbon alone

Insular ribbon yes, the rest no.
10 minus 1 gives 9.

Example 3: caudate, lentiform and internal capsule

Three deep regions yes.
10 minus 3 gives 7.

Example 4: insular ribbon and all six cortical regions

I, M1, M2, M3, M4, M5 and M6 yes.
10 minus 7 gives 3.

Example 5: all ten regions

Every region yes.
ASPECTS 0.

History of the ASPECTS score

Barber PA, Demchuk AM, Zhang J and Buchan AM published the score in the Lancet in 2000, in "Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy". Their analysis compared scores of 7 or less with scores above 7 for independence at 3 months, and the paper states that this analysis is not a reason to exclude patients. The calculator returns the score without that split.

When it's used

ASPECTS is scored on an early non-contrast CT in suspected acute ischaemic stroke in the MCA territory, to describe how much early change is visible.

Where it's used

Emergency departments, stroke units and radiology departments.

Who uses it

Radiologists, neuroradiologists and stroke physicians who read the CT. The calculator counts the marked regions and subtracts.

Limits of the calculation

It depends on the person reading the scan. Early change can be subtle, and readers can disagree.
It covers the MCA territory. It doesn't score posterior-circulation strokes.
The calculator returns a number with no thresholds and doesn't decide on any procedure.
Equal weighting means the score doesn't reflect how much tissue each region holds.
This page doesn't say what a result means for a particular person.

Clinical decisions belong to a qualified clinician who knows the patient.

NIHSS scores the clinical examination. ASPECTS scores the CT.
LAMS is a three-item motor score used before hospital.
Modified Rankin describes disability after stroke.
ICH score applies to bleeding strokes, not ischaemic change.

Glossary

MCA: middle cerebral artery, which supplies much of the side of the brain.
Early ischaemic change: focal swelling or reduced density of tissue on CT soon after a stroke.
Non-contrast CT: a CT scan done without injected dye.
pc-ASPECTS: a separate score for the posterior circulation.

Common mistakes

Counting up instead of down. ASPECTS starts at 10 and falls as regions are involved.
Weighting large regions more. Each region is worth 1.
Scoring a posterior stroke. Use pc-ASPECTS for that territory, not this score.
Treating the number as a rule. Barber's split at 7 isn't a reason to exclude anyone, and the calculator applies no cut-off.

Source

Barber PA, et al. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. Lancet. 2000;355(9216):1670-1674. DOI: 10.1016/S0140-6736(00)02237-6. PMID: 10905241

Frequently asked questions

What does ASPECTS stand for?

Alberta Stroke Program Early CT Score.

Is a higher ASPECTS better?

A higher score means fewer regions show early ischaemic change. 10 means none.

Does the calculator read the CT scan?

No. You mark each region yes or no, and the calculator does the subtraction.

Which regions are included?

Caudate, lentiform, internal capsule, insular ribbon and the six MCA cortical regions M1 to M6.

Does ASPECTS apply to posterior-circulation strokes?

No. Those use a separate score, pc-ASPECTS.