FLAIR Vascular Hyperintensities in Acute Ischemic Stroke
Summary
Fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities are linear or curvilinear regions of increased signal seen on FLAIR MRI sequences in patients with acute ischaemic stroke. These hyperintense vessels reflect areas of sluggish or redirected blood flow that arise when a primary artery is stenosed or occluded. By revealing the presence and extent of collateral circulation, FLAIR vascular hyperintensities offer an indirect measure of haemodynamic status and tissue viability. Extensive hyperintensities may indicate robust leptomeningeal collaterals that sustain penumbral tissue, whereas discrete or scant hyperintensities can signal insufficient perfusion and a higher risk of infarct growth. When interpreted alongside diffusion-weighted imaging and perfusion metrics, FLAIR vascular hyperintensities enhance patient selection for reperfusion therapies and improve prognostic accuracy. Ongoing research seeks to clarify how the temporal evolution of these signs relates to treatment windows and long-term functional recovery.
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FLAIR Vascular Hyperintensities in Acute Ischemic Stroke publication trend
The graph below shows the total number of articles in flair vascular hyperintensities in acute ischemic stroke across all publications each year (not limited to Nature Index journals).
Technical terms
Fluid-attenuated inversion recovery (FLAIR): An MRI sequence that nulls cerebrospinal fluid signal to highlight parenchymal and vascular abnormalities.
FLAIR vascular hyperintensity (FVH): High-signal vessels on FLAIR images indicating slow or collateral blood flow in ischaemic settings.
Collateral circulation: Alternative vascular channels that maintain perfusion distal to an arterial stenosis or occlusion.
Diffusion-weighted imaging (DWI): MRI technique detecting acute ischaemic injury by measuring water molecule diffusion.
ASPECTS (Alberta Stroke Program Early CT Score): A semiquantitative measure of early ischaemic changes in the middle cerebral artery territory on CT or MRI.
DWI–FLAIR mismatch: A pattern in which DWI shows restricted diffusion but FLAIR shows limited or no hyperintensity, suggestive of very recent infarction.
References
- FLAIR vascular hyperintensity combined with asymmetrical prominent veins in acute anterior circulation ischemic stroke: prediction of collateral circulation and clinical outcome. European Journal of Medical Research (2023).
- Angiography Reveals That Fluid-Attenuated Inversion Recovery Vascular Hyperintensities Are Due to Slow Flow, Not Thrombus. American Journal of Neuroradiology (2008).
- Application of FLAIR Vascular Hyperintensity-DWI Mismatch in Ischemic Stroke Depending on Semi-Quantitative DWI-Alberta Stroke Program Early CT Score. Frontiers in Neurology (2019).
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