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.
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.
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).
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.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Stroke and Cerebrovascular Diseases
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association.Stroke. 2013; 44 (on behalf of the; American Heart Association Stroke Council): 870-947
- 2015 American Heart Association/American Stroke Association focused update of the 2013 guidelines for the early management of patients with acute ischemic stroke regarding endovascular treatment: a guideline for healthcare professionals from the American Heart Association/American Stroke Association.Stroke. 2015; 46: 3020-3035
- Perfusion computed tomography: prediction of final infarct extent and stroke outcome.Ann Neurol. 2005; 58: 672-679
- Identification of infarct core and penumbra in acute stroke using CT perfusion source images.AJNR Am J Neuroradiol. 2010; 31: 34-39
- Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score.Lancet. 2000; 355: 1670-1674
- Use of the Alberta Stroke Program Early CT Score (ASPECTS) for assessing CT scans in patients with acute stroke.AJNR Am J Neuroradiol. 2001; 22: 1534-1542
- Trial design and reporting standards for intra-arterial cerebral thrombolysis for acute ischemic stroke.Stroke. 2003; 34: e109-e137
- Accuracy of the Alberta Stroke Program Early CT Score during the first 3 hours of middle cerebral artery stroke: comparison of noncontrast CT, CT angiography source images, and CT perfusion.AJNR Am J Neuroradiol. 2008; 29: 931-936
- Acute brain infarct: detection and delineation with CT angiographic source images versus nonenhanced CT scans.Radiology. 2007; 244: 541-548
- ASPECTS on CTA source images versus unenhanced CT: added value in predicting final infarct extent and clinical outcome.Stroke. 2004; 35: 2472-2476
- Comparison of CT and CT angiography source images with diffusion-weighted imaging in patients with acute stroke within 6 hours after onset.Stroke. 2002; 33: 2426-2432
- CT angiography with whole brain perfused blood volume imaging: added clinical value in the assessment of acute stroke.Stroke. 2002; 33: 959-966
- Comparison of perfusion computed tomography and computed tomography angiography source images with perfusion-weighted imaging and diffusion-weighted imaging in patients with acute stroke of less than 6 hours' duration.Stroke. 2004; 35: 1652-1658
- Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis: prediction of final infarct volume and clinical outcome.Stroke. 2001; 32: 2021-2028
- CT angiographic source images: flow- or volume-weighted?.AJNR Am J Neuroradiol. 2011; 32: 359-364
- Are CT angiography source images accurate for evaluating infarct volume?.J Neuroimaging. 2013; 23: 163-164
- CT angiography source images with modern multisection CT scanners: delay time from contrast injection to imaging determines correlation with infarct core.AJNR Am J Neuroradiol. 2012; 33: E61
- CT angiographic source images with modern multisection CT scanners: appropriate injection protocol is crucial.AJNR Am J Neuroradiol. 2011; 32: E93
- Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 2: technical implementations.AJNR Am J Neuroradiol. 2009; 30: 885-892
- Classification and pathogenesis of cerebral hemorrhages after thrombolysis in ischemic stroke.Stroke. 2006; 37: 556-561
- Hemorrhagic transformation after cerebral infarction: current concepts and challenges.Ann Transl Med. 2014; 2: 81
- CT angiographic source images predict outcome and final infarct volume better than noncontrast CT in proximal vascular occlusions.Stroke. 2011; 42 (for the; Calgary CTA Group): 1575-1580
- Acute ischemic stroke: infarct core estimation on CT angiography source images depends on CT angiography protocol.Radiology. 2012; 262: 593-604
- Collateral lessons from recent acute ischemic stroke trials.Neurol Res. 2014; 36: 397-402
- Collateral circulation predicts the size of the infarct core and the proportion of salvageable penumbra in hyperacute ischemic stroke patients treated with intravenous thrombolysis.Cerebrovasc Dis. 2015; 40: 182-190
- Collateral flow predicts response to endovascular therapy for acute ischemic stroke.Stroke. 2011; 42: 693-699
Published online: October 24, 2016
Accepted: September 15, 2016
Received in revised form: August 6, 2016
Received: June 16, 2016
© 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.