Accuracy of delayed post-contrast flair MR imaging for the diagnosis of leptomeningeal infectious or tumoral diseases

Aims: To compare unenhanced, gadolinium enhanced, delayed gadolinium enhanced FLAIR images, gadolinium, enhanced and delayed gadolinium enhanced T1 images in different types of leptomeningeal diseases, and to determine the most accurate MRI sequence for the diagnosis of leptomeningeal disease. Material and methods: Ten patients (6 men, 4 women, age: 52,7+/-16,4) clinically suspected of cerebral leptomeningeal infectious or tumoral disease underwent brain MR examination: Axial FLAIR and T1 SE images were acquired before, immediately after administration of gadobenate dimeglumine (0.1mmol per kilogram of body weight) (early enhancement), and 20 minutes after injection of contrast media (delayed enhancement). Images were analysed to determine the more appropriate technique for the diagnosis of leptomeningeal disease. Results: Early enhanced FLAIR and delayed enhanced T1 were always more or equally accurate for the diagnosis of leptomeningeal diasease, as compared to, respectively, unenhanced FLAIR and early enhanced T1 images Delayed enhanced FLAIR was always more accurate for the diagnosis of leptomeningeal disease as compared to early enhanced FLAIR images. Delayed enhanced FLAIR was in most of the cases more accurate for the diagnosis of leptomeningeal disease as compared to delayed enhanced T1 images. Conclusion: Delayed enhanced FLAIR MR sequence seems to improve the diagnosis of leptomeningeal infectious or tumoral diseases as compared to other MR sequences.