Sequential contrast-enhanced magnetic resonance imaging in the diagnosis of growth hormone deficiencies

The purpose of the present study was to assess the presence and the time-co urse of contrast-enhancement in the pituitary gland and pituitary stalk of 24 patients with isolated growth hormone (GH) deficiency and multiple pitui tary hormone deficiency. The patients were evaluated clinically (auxologica l measurements), endocrinologically (spontaneous GH secretion and GH stimul ation tests) and with conventional MRI scans. In addition, fast-framing dyn amic magnetic resonance imaging (MRI) with Gd-DTPA enhancement was used to quantitate the time course of contrast enhancement within the neurohypophys is, pituitary stalk, postero-superior adenohypophysis and antero-inferior a denohypophysis. In 3 patients without evidence of abnormalities at normal c onventional MRI scans (normal anterior lobe and pituitary stalk, normal pos terior lobe) and a high response to the GRF provocation test, sequential ti me-resolved Gd-enhanced MRI demonstrates reduced contrast enhancement in th e pituitary stalk. These findings are consistent with impairment in stalk v asculature, presumably located at the level of the portal venous system, an d could play a role in the pathogenesis of pituitary hormonal deficiency. ( J. Endocrinol. Invest. 22: 740-746, 1999) (C)1999, Editrice Kurtis.