Utility of magnetic resonance imaging in the evaluation of the child with central diabetes insipidus.

Because of the association of central diabetes insipidus (CDI) and occult neoplasia, magnetic resonance imaging (MRI) is an important component of the diagnostic evaluation of a child with CDI. In more than 90% of these children, MRI (T1 weighted-image, without contrast) demonstrates an absence of the normal hyperintensity of the posterior pituitary. In one third of patients, the pituitary stalk is also thickened, suggesting infiltrative disease. Of those with a thickened stalk, the etiology of the CDI remains undetermined in about 60% of patients, whereas histiocytosis and occult germinoma each account for approximately 15-20% of patients. In contrast, germinoma is infrequent (3%) in children with CDI and an MRI showing a normal infundibular stalk, though histiocytosis still accounts for 15-20% of patients. In this paper, a diagnostic approach in children with CDI is proposed.