Contrast-enhanced Fast Fluid-attenuated Inversion Recovery MR Imaging in Patients with Brain Tumors

ABSTRACT

PURPOSE: To assess the feasibility of contrast-enhanced fast fluid-attenuated inversion recovery (fast FLAIR) MR imaging in patients with brain tumors. MATERIALS AND METHODS: This study involved 31 patients with pathologically proven brain tumors and nine with clinically diagnosed metastases. In all patients, T2-weighted, fast FLAIR, contrast-enhanced fast FLAIR and contrast-enhanced T1-weighted MR images were obtained. Contrast-enhanced fast FLAIR images were visually compared with other MR sequences in terms of tumor conspicuity. In order to distinguish tumor and surrounding edema, contrast-enhanced fast FLAIR images were compared with fast FLAIR and T2-weighted im-ages. The tumor-to- white matter contrast-to-noise ratios (CNRs), as demonstrated by T2-weighted, fast FLAIR, contrast-enhanced fast FLAIR and contrast-enhanced T1-weighted imaging, were quantitatively assessed and compared. RESULTS: For the visual assessment of tumor conspicuity, contrast-enhanced fast FLAIR image imaging superior to fast FLAIR in 60% of cases (24/40), and superior to T2-weighted in 70% (28/40). Contrast-enhanced fast FLAIR imaging was inferior to contrast-enhanced T1-weighted in 58% of cases (23/40). For distinguishing between tumor and surrounding edema, contrast-enhanced fast FLAIR imaging was superior to fast FLAIR or T2-weighted in 22 of 27 tumors with peritumoral edema (81%). Quantitatively, CNR was the highest on contrast-enhanced fast FLAIR image and the lowest on fast FLAIR. For the detection of leptomeningeal metastases, contrast-enhanced fast FLAIR was partially superior to contrast-enhanced T1-weighted imaging in two of three high-grade gliomas. CONCLUSION: Although contrast-enhanced fast FLAIR imaging should not be seen as a replacement for conventional modalities, it provides additional information for assessment of the extent of glial cell tumors and leptomeningeal metastases in patients with brain tumors.