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  • Review Article
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Imaging of acute stroke

Nature Reviews Neurology volume 6, pages 560–571 (2010)Cite this article

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Abstract

Brain imaging provides an objective basis for the clinical inferences that direct individual patient management in the acute stroke setting. A brain CT or MRI scan is required for all patients with suspected stroke or transient ischemic attack. Thrombolytic therapy is arguably the most important aspect of acute stroke management; however, most decisions in acute stroke do not relate to this treatment. Stroke imaging must, therefore, provide information beyond the presence or absence of intracranial hemorrhage (ICH) and early evidence of a large infarct. Noncontrast CT and gradient-recalled echo MRI show comparable accuracy in the diagnosis of acute ICH. Diffusion-weighted MRI is more sensitive than noncontrast CT for differentiation of acute ischemic stroke from nonstroke conditions. Combined multimodal parenchymal, perfusion and vascular imaging with CT or MRI has the potential to identify patients with an ischemic penumbra that might be appropriate for acute reperfusion therapies. MRI identifies a broader range of acute and chronic cerebrovascular pathologies than does CT and, hence, could aid decisions about acute intervention, in-hospital management, and secondary prevention. Here, we present an overview of the diagnostic information that clinicians might gain from CT and MRI in the setting of acute stroke, along with the advantages and disadvantages of these techniques.

Key Points

  • A brain CT or MRI scan is urgently recommended for all patients with suspected acute stroke or transient ischemic attack

  • Noncontrast CT and gradient-recalled echo MRI show similar accuracy in the diagnosis of acute intracerebral hemorrhage

  • Diffusion-weighted MRI is markedly more sensitive than noncontrast CT for distinguishing acute ischemic stroke from nonstroke conditions

  • Combined multimodal parenchymal, perfusion and vascular imaging with CT or MRI could potentially identify patients with an ischemic penumbra that might be amenable to acute reperfusion therapies

  • MRI identifies a broad range of acute and chronic cerebrovascular pathologies that could aid decisions about acute intervention, in-hospital management and secondary prevention

  • Overall, MRI is diagnostically superior to CT for cerebrovascular indications, but is contraindicated in ≈10% of patients, has limited availability at many hospitals, and can be costly and time-consuming

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Figure 1: Multimodal CT survey.
Figure 2: Multimodal MRI.
Figure 3: Suceptibility-weighted imaging.

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Acknowledgements

This work was supported by the Division of Intramural Research of the National Institute of Neurological Disorders and Stroke, NIH. Laurie Barclay, freelance writer and reviewer, is the author of and is solely responsible for the content of the learning objectives, questions and answers of the MedscapeCME-accredited continuing medical education activity associated with this article.

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Authors and Affiliations

  1. Suburban Hospital Stroke Program, 8600 Old Georgetown Road, Bethesda, 20007, MD, USA

    José G. Merino

  2. Section on Stroke Diagnostics and Therapeutics, National Institute of Neurological Disorders and Stroke, Room B1D-733, MSC 1063, National Institutes of Health, Bethesda, 20892, MD, USA

    Steven Warach

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  1. José G. Merino
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Both authors contributed equally to this Review.

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Correspondence to Steven Warach.

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Merino, J., Warach, S. Imaging of acute stroke. Nat Rev Neurol 6, 560–571 (2010). https://doi.org/10.1038/nrneurol.2010.129

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