Hyperintensity in the subarachnoid space on FLAIR MRI

Abstract

Objective: The purposes of this essay are to illustrate the causes of FLAIR hyperintensity in the subarachnoid space and to outline the mechanisms of the findings.

Conclusion: FLAIR subarachnoid space hyperintensity may be encountered with both pathological conditions and artifacts. Knowledge of these conditions and appearances coupled with any associated findings may suggest the cause of the FLAIR subarachnoid space hyperintensity. A diffuse distribution and a lack of ancillary findings often remain nonspecific and may require clinical correlation and CSF analysis.