T2-FLAIR
What is T2-FLAIR?
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T2-FLAIR stands for T2-weighted-Fluid-Attenuated Inversion Recovery. Originally just called "FLAIR", this technique was developed in the early 1990's by the Hammersmith research team led by Graeme Bydder, Joseph Hajnal, and Ian Young. Their original sequences used TI values of 2000-2500 to null signal from CSF, coupled with very long TRs (8000) and TEs (140) to create strong T2-weighting.
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Notwithstanding very long imaging times (15-20 min typical), the T2-FLAIR technique repeatedly proved itself by revealing a wide range of lesions, including cortical, periventricular, and meningeal diseases that were difficult to see on conventional images. By the late 1990s the use of fast spin echo signal generation significantly reduced imaging times and T2-FLAIR became a standard protocol for routine imaging. Today, the venerable old spin-density sequences (long TR/Short TE spin echo) have been nearly completely replaced by T2-FLAIR imaging, at least in neuroimaging.
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T2-FLAIR brain image
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References
Hajnal JV, De Coene B, Lewis PD, et al. High signal regions in normal white matter shown by heavily T2-weighted CSF nulled IR sequences. J Comput Assist Tomogr 1992; 16:506-13.
Hajnal JV, Bryant DJ, Kasuboski L, et al. Use of Fluid Attenuated Inversion Recovery (FLAIR) pulse sequences in MRI of the brain. J Comput Assist Tomogr 1992; 16:841-844.
Hajnal JV, De Coene B, Lewis PD, et al. High signal regions in normal white matter shown by heavily T2-weighted CSF nulled IR sequences. J Comput Assist Tomogr 1992; 16:506-13.
Hajnal JV, Bryant DJ, Kasuboski L, et al. Use of Fluid Attenuated Inversion Recovery (FLAIR) pulse sequences in MRI of the brain. J Comput Assist Tomogr 1992; 16:841-844.