Pituitary stalk and ectopic hyperintense T1 signal on magnetic resonance imaging. Implications for anterior pituitary dysfunction.

ABSTRACT

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.