MAGNETIC-RESONANCE-IMAGING OF POSTERIOR PITUITARY FOR EVALUATION OF THE NEUROHYPOPHYSEAL FUNCTION IN IDIOPATHIC AND AUTOSOMAL-DOMINANT NEUROHYPOPHYSEAL DIABETES-INSIPIDUS

We investigated the role of MR imaging for evaluation of the functiona l status of the neurohypophyseal in both idiopathic central diabetes i nsipidus (DI) and familial autosomal dominant neurohypophyseal DI. the patients and family with DI were analyzed retrospectively for the pre sence or absence of posterior pituitary gland hyperintense signal on M R images. A total of 19 adult patients with idiopathic central DI, 7 m embers of a family with autosomal dominant DI and 20 control subjects were in included in the study. Diagnosis of idiopathic DI was based on the presence of central DI in the absence of any alteration that is k nown to be responsible for DI. patients were studied retrospectively a nd the morphology and intensity of the posterior lobe by MR imaging wa s assessed by blinded reading. In all patients with idiopathic central DI and the affected members of the family, the posterior bright signa l was absent while the stalk was normal on MR images. contrast, normal posterior pituitary bright al and stalk were found in unaffected memb ers of the family and all control subjects. We conclude that MR imagin g of the posterior pituitary lobe can be used to evaluate the function al status of the neurohypophyseal system in idiopathic central DI and familial autosomal dominant DI.