Fluid-attenuated-inversion-recovery (FLAIR) imaging in the diagnosis of cerebral gliomas and metastases

Abstract

This study demonstrates the value of a fast fluid-attenuated inversion-recovery (FLAIR) technique in the assessment of cerebral gliomas and metastases. Thirty-five patients with cerebral gliomas and 12 patients with a total of 39 cerebral metastases were examined by T2/proton density-weighted fast spin echo, fast FLAIR with and without contrast medium and contrast-enhanced T1-weighted spin echo using identical slice parameters. The images were evaluated using quantitative and qualitative criteria. Quantitative criteria were tumor-to-background and tumor-to-cerebrospinal fluid contrast and contrast-to-noise. The qualitative evaluation was performed as a multireader analysis 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 < 0.001) and the delineation of enhancing and non-enhancing tumor parts. Fast FLAIR was superior in the delineation of cortically located and small lesions but was limited in lesions adjacent to the ventricles. Fast FLAIR provided significantly 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-to-noise of the fast FLAIR images were lower than that of T2-weighted spin-echo images but were significantly increased after the application of contrast medium. FLAIR images had a more image artifacts, but these influenced the image interpretation in only two patients. Signal hyperintensities at the ventricular border were present in 92% of the patients. These are common findings in fast FLAIR and should be included in image interpretation.