Pituitary Stalk and Ectopic Hyperintense T1 Signal on Magnetic Resonance Imaging

OBJECTIVE: To determine if improved delineation of hypothalamic-pituitary neuroanatomy by magnetic resonance imaging, especially the posterior pituitary hyperintense T1 signal, can be correlated with anterior and posterior pituitary endocrine function. DESIGN: Children with ectopic posterior pituitary tissue were identified at the Endocrine Clinic of the Children's Hospital of Pittsburgh (Pa) and their records were reviewed. PARTICIPANTS: Ten children with ectopic posterior pituitary tissue. MEASUREMENTS: Anterior pituitary hormone status, determined by standard testing, was correlated with the morphologic anomalies of the hypothalamic-pituitary region on magnetic resonance imaging. RESULTS: Patients were categorized by the appearance of the pituitary stalk based on the magnetic resonance image: attenuation of the stalk (group 1) or nonvisualization of the stalk (group 2). Patients in group 1 retained partial anterior pituitary function. Patients in group 2 had panhypopituitarism. CONCLUSION: Prospective evaluation of affected individuals may provide insight into the pathophysiologic mechanisms of idiopathic hypopituitarism.