Legend Axial T2 weighted images demonstrate bilateral diffuse increased signal intensity of the white matter in the brainstem, cerebellar peduncles, and cerebellum.

Legend Axial T2, left, and axial FLAIR, right, images also demonstrate abnormal white matter signal intensity in the posterior limb of the internal capsules, in the genu of the corpus callosum, and in the anterior commissure.

Legend Despite the extensive white matter involvement there is no abnormal enhancement following contrast administration. Key words: mri phakomatoses

Brain Diagnosis: Dysmyelination (vacuolar myelin) Neurofibromatosis, Type 1