Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2021 Nov 16;97(20 Suppl 2):S42-S51.
doi: 10.1212/WNL.0000000000012794.

Overview of Imaging Modalities in Stroke

Alexandra L Czap  1 , Sunil A Sheth  2
Affiliations
Review

Overview of Imaging Modalities in Stroke

Alexandra L Czap et al. Neurology. .

Abstract

Purpose of the review: This article reviews common imaging modalities used in diagnosis and management of acute stroke. Each modality is discussed individually and clinical scenarios are presented to demonstrate how to apply these modalities in decision-making.

Recent findings: Advances in neuroimaging provide unprecedented accuracy in determining tissue viability as well as tissue fate in acute stroke. In addition, advances in machine learning have led to the creation of decision support tools to improve the interpretability of these studies.

Summary: Noncontrast head computed tomography (CT) remains the most commonly used initial imaging tool to evaluate stroke. Its exquisite sensitivity for hemorrhage, rapid acquisition, and widespread availability make it the ideal first study. CT angiography (CTA), the most common follow-up study after noncontrast head CT, is used primarily to identify intracranial large vessel occlusions and cervical carotid or vertebral artery disease. CTA is highly sensitive and can improve accuracy of patient selection for endovascular therapy through delineations of ischemic core. CT perfusion is widely used in endovascular therapy trials and benefits from multiple commercially available machine-learning packages that perform automated postprocessing and interpretation. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) can provide valuable insights for outcomes prognostication as well as stroke etiology. Optical coherence tomography (OCT), positron emission tomography (PET), single-photon emission computerized tomography (SPECT) offer similar insights. In the clinical scenarios presented, we demonstrate how multimodal imaging approaches can be tailored to gain mechanistic insights for a range of cerebrovascular pathologies.

PubMed Disclaimer

Conflict of interest statement

A. Czap is funded by a grant from the NIH (2T32NS007412-21). S. Sheth served at the Neuroimaging Core Laboratory for Penumbra COMPLETE registry; performs neuroimaging in his clinical practice and bills for this procedure; and is funded by grants from the NIH (U18EB029353 and R01NS121154), American Academy of Neurology/Society of Vascular and Interventional Neurology, and the Translational Research Institute for Space Health (19-19BRASH-2-0030). Go to Neurology.org/N for full disclosures.

Figures

Figure 1
Figure 1. Illustrative Example of Neuroimaging Applications for Intracranial Hemorrhage (ICH)
Noncontrast head CT (A), MRI gradient recalled echo (B), CT angiography (CTA) (C), and maximum intensity projection CTA (D) images demonstrate multiple representations of acute ICH.
Figure 2
Figure 2. Illustrative Example of Neuroimaging Applications for Large Vessel Occlusion Acute Ischemic Stroke
Noncontrast head CT (A), maximum intensity projection CT angiography (CTA) (B), postprocessed CT perfusion maps (C), and left carotid artery injection digital subtraction angiography (DSA) (D) demonstrate findings associated with acute left internal carotid artery terminus occlusion. Postrecanalization images are provided as left internal carotid artery injection DSA (E) and fluid-attenuated inversion recovery MRI (F). MTT = mean transit time; rCBF = relative cerebral blood flow; rCBV = relative cerebral blood volume; Tmax = time to maximum of residue function.
Figure 3
Figure 3. Illustrative Example of Neuroimaging Applications in Carotid Stenosis
MRI diffusion-weighted imaging (A), 3D reconstructed CT angiography (B), and right common carotid artery injection digital subtraction angiography (C) images are provided characterizing features associated with right internal carotid artery stenosis.
Figure 4
Figure 4. Illustrative Example of Neuroimaging Evaluations for Intracranial Stenotic Disease
MRI diffusion-weighted imaging (A), contrast-enhanced T1 MRI (B), left internal carotid artery injection digital subtraction angiography (C), postprocessed CT perfusion maps (D), and acetazolamide SPECT (E) images demonstrate features associated with left intracranial carotid artery stenosis. MTT = mean transit time; Tmax = time to maximum of residue function.
See this image and copyright information in PMC

References

    1. Mettler FA Jr, Huda W, Yoshizumi TT, Mahesh M. Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology. 2008;248(1):254-263. - PubMed
    1. Osborn AG. Diagnostic imaging. Brain, 2nd ed. Amirsys; 2010.
    1. von Kummer R, Bourquain H, Bastianello S, et al. . Early prediction of irreversible brain damage after ischemic stroke at CT. Radiology. 2001;219(1):95-100. - PubMed
    1. Wardlaw JM, Mielke O. Early signs of brain infarction at CT: observer reliability and outcome after thrombolytic treatment: systematic review. Radiology. 2005;235(2):444-453. - PubMed
    1. Barber PA, Demchuk AM, Zhang J, Buchan AM. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy: Alberta Stroke Programme Early CT Score. Lancet. 2000;355(9216):1670-1674. - PubMed

Publication types