ASPECTS on CTA source images versus unenhanced CT: added value in predicting final infarct extent and clinical outcome.
OBJECTIVE
The Alberta Stroke Program Early CT Score (ASPECTS) is a grading system to assess ischemic changes on CT in acute ischemic stroke. CT angiography-source images (CTA-SI) predict final infarct volume. We examined whether the final infarct ASPECTS and clinical outcome were more related to acute CTA-SI ASPECTS than to the acute noncontrast CT (NCCT) ASPECTS.


METHODS
ASPECTS was assigned by 2 raters on the acute NCCT, CTA-SI, and follow-up imaging. The mean baseline ASPECTS of acute NCCT and CTA-SI was compared with the follow-up ASPECTS. Rate ratios (RRs) were used to quantify the relationship between the dichotomized baseline ASPECTS (categorized as 0 to 7 versus 8 to 10) and favorable patient outcome.


RESULTS
Thirty-nine patients were recruited. Proximal occlusion (internal carotid artery or middle cerebral artery) was seen in 62%, M2 occlusion in 18%, and no occlusion was seen in 20% of patients. The median time between symptom onset and imaging was 1.9 (1.2 to 2.5) hours. There was a significantly larger difference of 1.4 between the mean baseline NCCT and CTA-SI ASPECTS in patients who had more ischemic changes (follow-up ASPECTS=0 to 3) than a difference of 0.6 in patients who had near-to-normal CT scans (follow-up ASPECTS=8 to 10). The rate of favorable outcome for acute NCCT ASPECTS of 8 to 10 was 51.8% versus 25.0% for 0 to 7 (RR, 2.1, 95% CI: 0.7 to 5.9, P=0.12). For acute CTA-SI ASPECTS of 8 to 10, the rate of favorable outcome was 58.8% versus 31.8% for 0 to 7 (RR, 1.8, 95% CI: 0.9 to 3.8, P=0.09).


CONCLUSIONS
CTA-SI ASPECTS provides added information in the prediction of final infarct size.
Seaman Family MR Centre, Foothills Hospital, Calgary Health Region, 1403 29th ST NW, Calgary, Alberta T2N 2T9, Canada. shelagh.coutts@calgaryhealthregion.ca
Shelagh B
SB
Coutts
Michael H
MH
Lev
Michael
M
Eliasziw
Luca
L
Roccatagliata
Michael D
MD
Hill
Lee H
LH
Schwamm
J H Warwick
JH
Pexman
Walter J
WJ
Koroshetz
Mark E
ME
Hudon
Alastair M
AM
Buchan
R Gilberto
RG
Gonzalez
Andrew M
AM
Demchuk
D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed