[Magnetic resonance imaging and hypothalamo-hypophyseal disorders in children: morpho-functional and etiologic aspects].

In recent years magnetic resonance (MR) has improved the diagnostic accuracy of the study of the sellar area. In patients with growth hormone deficiency, particularly when associated with other hormonal defects, MR has identified the picture characterized by posterior lobe ectopia, non-visible stalk, hypoplasia of the anterior lobe and presence of intrasellar CSF (empty sella). The latter is not exclusive of growth hormone deficient patients, but can be found also in children with disorders of puberty. Although a certain relationship between pituitary height and growth hormone secretion has been described, it is usually difficult to find a clear association between pituitary dimensions and function of the gland. The theory supporting the congenital origin of the above mentioned abnormalities, which may be part of midline abnormalities, is currently sustained by most Authors. In diabetes insipidus the posterior lobe may or may not be visible and a thickened stalk has been found in patients with disease duration of less than 2 years. In disorders of puberty morphological abnormalities of the sellar area are rare. In girls with precocious puberty the pathological findings described are hamartoma of the tuber cinereum, empty sella and pituitary height increased for age. There seems to be a certain relationship between gonadotropin secretion and pituitary dimensions.