Post-traumatic diabetes insipidus: MR demonstration of pituitary stalk rupture.

We report the magnetic resonance findings in a case of post-traumatic diabetes insipidus (DI). They consisted of pituitary stalk rupture shown on both coronal and sagittal planes with associated disappearance of the normal high signal intensity of the posterior lobe on T1 images. This last sign, previously described in nontraumatic DI, appears to represent a finding indicating nonfunctioning neurohypophysis.