MR findings in hereditary isolated growth hormone deficiency.

PURPOSE: To describe the MR characteristics by which patients with hereditary isolated growth hormone deficiency (GHD) can be distinguished from patients with other types of GHD. METHODS: A total of 51 patients with GHD were examined prospectively with MR imaging. On the basis of familial occurrence of GHD and genetic analysis, 10 patients met the criteria for hereditary deficiency. In each case, the height of the pituitary gland, the presence and location of the posterior neurohypophysis, and the completeness of the stalk were recorded. The findings in the hereditary group were compared with those in the rest of the patients. RESULTS: In all 10 patients with hereditary GHD, the adenohypophysis, the neurohypophysis, and the stalk were normal. Of the other 41 patients, the height of the gland was normal in three (7%), the neurohypophysis was abnormal in all, and the stalk was truncated in all but two patients (95%). CONCLUSIONS: The subgroup of patients with hereditary GHD exhibited an anatomically normal pituitary-hypothalamic region. This is in contrast to the majority of patients with idiopathic GHD. MR imaging can contribute to the classification of patients with GHD.