FLAIR imaging in the diagnosis of cerebral gliomas and metastases

This study demonstrates the value of a fast fluid-attenuated inversion-reco very (FLAIR) technique in the assessment of cerebral gliomas and metastases . Thirty-five patients with cerebral gliomas and 12 patients with a total o f 39 cerebral metastases were examined by T2/proton density-weighted fast s pin echo,fast FLAIR with and without contrast medium and contrast-enhanced T1-weighted spin echo using identical slice parameters. The images were eva luated using quantitative and qualitative criteria. Quantitative criteria w ere tumor-to-background and tumor-to-cerebrospinal fluid contrast and contr ast-to-noise,The qualitative evaluation was performed as a multireader anal ysis concerning lesion detection,lesion delineation and image artifacts. In the qualitative evaluation, all readers found fast FLAIR to be superior to fast spin echo in the exact delineation of cerebral tumors (P<0.007) and t he delineation of enhancing and non-enhancing tumor parts. Fast FLAIR was s uperior in the delineation of cortically located and small lesions but was limited in lesions adjacent to the ventricles. Fast FLAIR provided a signif icantly better tumor-to-CSF contrast-and tumor-to-CSF contrast-to-noise (P< 0.001). The tumor-to-background contrast and tumor-to-background contrast-t o-noise of the fast FLAIR images were lower than that of T2-weighted spin-e cho images but were significantly increased after the application of contra st medium. FLAIR images had a more image artifacts, but these influenced th e image interpretation in only two patients. Signal hyperintensities at the ventricular border were present in 92% of the patients. These are common f indings in fast FLAIR and should be included in image interpretation.