T2 FLAIR: why the CSF is dark and what it finds
FLAIR cancels the CSF signal so lesions beside the ventricles and sulci stand out. These are its uses and its artifacts.
T2 FLAIR
A T2 image with CSF made black. Lesions next to CSF stay bright.
Periventricular and cortical lesions (demyelination, small-vessel disease, cortical infarct, encephalitis). Abnormal bright sulci point to blood, pus or protein in the subarachnoid space.
CSF flow artifacts in the posterior fossa and basal cisterns. Supplemental oxygen and recent gadolinium also make CSF bright.
This page is one entry from the MRI Technologist Reference
The full reference has 31 protocols, 9 dynamic study timelines, 19 artifacts, 16 scanner problems and 15 safety topics, as a PDF in English and Arabic plus an interactive tool.
Educational reference. It does not replace your site protocols, the radiologist's instructions, the MR safety officer, or the manufacturer's instructions for any implant, device or contrast agent. Parameter values are typical starting points at 1.5 T and must be adapted to the scanner, coil and patient.