Magnetic resonance imaging in growth hormone deficiency: Relationship between endocrine function and morphological findings

Magnetic resonance imaging (MRI) using gadopentetate dimeglumine (Gd-DTPA) improves the delineation of hypothalamic-pituitary structures and facilitat es the detection of anatomical abnormalities which are indicators of perman ent growth hormone deficiency (GHD), The aim of this study was to determine the frequency of neuroradiological abnormalities in 85 (52 M, 33 F) patien ts with hereditary or idiopathic forms of isolated GHD (IGHD) or multiple p ituitary hormone deficiency (MPHD) and also to investigate the relationship between anatomical findings and hormonal status. Pituitary hypoplasia with absent or thin infundibulum and ectopic posterior pituitary (EPP) were the most frequent findings in 39 patients with MPHD, whereas in 46 patients wi th IGHD the most frequent finding was pituitary hypoplasia without neurorad iological abnormalities. All patients whose infundibulum was not visualized after Gd-DTPA injection belonged to the MPHD group; therefore, absence of pituitary stalk can be a good indicator of the severity of hormonal deficie ncies. Pituitary hypoplasia was found in all patients with familial IGHD, A mong patients with abnormalities of the hypothalamic pituitary area on MRT, normal or breech delivery frequency distributed equally. Therefore it seem s that mechanical or hypoxic prenatal events cannot be the primary etiologi cal factor in all patients with neuroradiological abnormalities since half of these patients had normal delivery and birth history. The localization o f the bright spot of the posterior pituitary at the level of the median emi nence, midstalk position or at the end of the infundibulum may suggest a ne uronal migration defect which may occur during early embryogenesis, In conc lusion, in children with GHD a careful examination of the hypothalamic pitu itary area by MRI after enhancement helps to establish the diagnosis and pr edicts the prognosis.