Background
There has been a recent debate regarding the superiority of computed tomography angiography
source images (CTASIs) over noncontrast computed tomography (NCCT) to predict the
final infarct size in acute ischemic stroke (AIS). We hypothesized that the parenchymal
abnormality on CTASI in faster scanners would overestimate ischemic core.
Methods
This prospective study assessed the correlation of Alberta Stroke Program Early CT
Score (ASPECTS) on NCCT, CTASI, and computed tomography perfusion (CTP) with final
infarct size in patients within 8 hours of AIS. Follow-up with NCCT or diffusion-weighted
magnetic resonance imaging (MRI) was performed at 24 hours. Correlations of NCCT and
CTASI with final infarct size and with CTP parameters were assessed. Subgroup analysis
was performed in patients who underwent intravenous thrombolysis or mechanical thrombectomy.
Inter-rater reliability was tested using Spearman's rank correlation. A P value less than .05 was considered statistically significant.
Results
A total of 105 patients were included in the final analysis. NCCT had a stronger correlation
with the final infarct size than did CTASI (Spearman's ρ = .85 versus .78, P = .13). We found an overestimation of the final infarct size by CTASI in 47.6% of
the cases, whereas NCCT underestimated infarct size in 60% of the patients. NCCT correlated
most strongly with CBV (ρ = .93), whereas CTASI correlated most strongly with CBF
(ρ = .87). Subgroup analysis showed less correlation of CTASI with final infarct size
in the group that received thrombolysis versus the group that did not (ρ = .70 versus
.88, P = .01).
Conclusion
In a 256-slice scanner, the CTASI parenchymal abnormality includes ischemic penumbra
and thus overestimates final infarct size—this could result in inappropriate exclusion
of patients from thrombolysis or thrombectomy.
Key Words
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Article info
Publication history
Published online: October 24, 2016
Accepted:
September 15,
2016
Received in revised form:
August 6,
2016
Received:
June 16,
2016
Identification
DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2016.09.026
Copyright
© 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.
