Magnetic resonance imaging. Its role in the neuroradiologic evaluation of neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome.

BACKGROUND: Magnetic resonance imaging (MRI) has rapidly become a major diagnostic technique, displacing computed tomography (CT) as the primary neuroimaging modality in many disorders of the central nervous system. Neuroimaging studies are valuable in the diagnosis and management of neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome. This article reviews the technique of MRI and its role in identifying the characteristic central nervous system manifestations of these neurocutaneous syndromes. OBSERVATIONS: MRI offers superior soft-tissue contrast without the use of ionizing radiation. It provides more detailed imaging than CT of the characteristic central nervous system lesions of neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome. In neurofibromatosis type 1, these include optic glioma, astrocytoma, and plexiform neurofibroma, and "unidentified bright objects" that are seen only with MRI. Bilateral acoustic neuromas are the hallmark of neurofibromatosis type 2. Subependymal nodules and cortical and white matter tubers are characteristic of tuberous sclerosis. Manifestations of Sturge-Weber syndrome include leptomeningeal angiomatosis, hemiatrophy, cortical calcification, and patchy parenchymal gliosis and demyelination.
CONCLUSIONS: MRI, especially with gadolinium enhancement, appears to be more sensitive than CT in the detection of neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome. MRI may be the imaging method of choice for following certain patients or screening family members.