Short tau inversion recovery
Short tau inversion recovery (STIR), also known as short TI inversion recovery, is a fat suppression technique with an inversion time TI = ln(2)·T1fat,
where the signal of fat is zero. This equates to approximately 140 ms at 1.5 T.
To distinguish two tissue components with this technique, their T1 values must be different. FLAIR is a similar technique to suppress water.
Inversion recovery imaging allows homogeneous and global fat suppression and can be used with low-field-strength magnets. However, this technique is not specific for fat. Thus, the signal intensity of tissue with a long T1 and tissue with a short T1 may cause ambiguity.
Since STIR sequences use short inversion recovery time, they cannot be used with gadolinium injection because tissues that take up gadolinium will exhibit T1 shortening and may inadvertently be nulled.
Related Radiopaedia articles
Physics and Imaging Technology: MRI
- MRI (introduction)
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MRI physics
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- chemical shift
- dependence of magnetization (proton density, field strength and temperature)
- echo time
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MRI pulse sequences (basics | abbreviations | parameters)
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perfusion-weighted imaging
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MR spectroscopy (MRS)
- 2-hydroxyglutarate peak: resonates at 2.25 ppm
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- choline peak: resonates at 3.2 ppm
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- creatine peak: resonates at 3.0 ppm
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- Hunter's angle
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MRI artifacts
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