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Intermediate Technical IVT

FLAIR

Also written as: FLAIR — Fluid-Attenuated Inversion Recovery

Fluid-attenuated inversion recovery MRI sequence that suppresses cerebrospinal fluid signal.

Full Definition

Fluid-attenuated inversion recovery (FLAIR) is a specialized MRI pulse sequence that nulls the signal from cerebrospinal fluid (CSF) while maintaining contrast between gray and white matter. This technique is particularly valuable in neuroimaging as it enhances the detection of pathology adjacent to CSF spaces, such as cortical lesions, periventricular abnormalities, and leptomeningeal disease. In oncologic imaging, FLAIR sequences are essential for detecting brain metastases, assessing tumor extent, and monitoring treatment response. The suppression of CSF signal prevents masking of subtle abnormalities that might otherwise be obscured by bright fluid signal.

Usage

Usage note: Capitalize when used as sequence name in imaging protocols.

In Context

  • "FLAIR images demonstrated multiple hyperintense cortical lesions consistent with metastatic disease." — Brain MRI report
  • "The tumor extent was better delineated on FLAIR sequences compared to standard T2-weighted images." — Preoperative imaging assessment

Also known as

fluid-attenuated inversion recovery

Don't confuse with

T2WI STIR T1WI

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