Brain: Gadolinium-enhanced fast fluid-attenuated inversion-recovery MR imaging

PURPOSE: To determine the clinical utility of gadolinium-enhanced fluid-att enuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the b rain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation. MATERIALS AND METHODS: In 105 consecutive patients referred for gadolinium- enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumin e (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and w hether enhancement was more conspicuous with the FLAIR or T1-weighted seque nces. RESULTS: Thirty-nine studies showed intracranial contrast enhancement. Post contrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhan cement in 15 studies. Four cases demonstrated approximately equal contrast enhancement with both sequences. Six cases showed some areas of enhancement better with T1-weighted imaging with MT saturation and other areas better with postcontrast fast FLAIR imaging. Superficial enhancement was typically better seen with postcontrast fast FLAIR imaging. CONCLUSION: Fast FLAIR images have noticeable T1 contrast making gadolinium -induced enhancement visible. Gadolinium enhancement in lesions that are hy perintense on precontrast FLAIR images, such as intraparenchymal tumors, ma y be better seen on T1-weighted images than on postcontrast fast FLAIR imag es. However, postcontrast fast FLAIR images may be useful for detecting sup erficial abnormalities, such as meningeal disease, because they do not demo nstrate contrast enhancement of vessels with slow flow as do T1-weighted im ages.