Role of magnetic resonance imaging in the diagnosis and prognosis of growth hormone deficiency

OBJECTIVE In patients with congenital GH deficiency (GHD), magnetic resonance imaging (MRI) has revealed morphological abnormalities such as pituitary hypoplasia, absence of the stalk and ectopia of the posterior pituitary (PPE). Our study was aimed at investigating the possible relationship between neuroradiological images and the presence of isolated GH or multiple pituitary hormone deficiency. DESIGN We studied 121 patients, aged 0.3-25 years, with isolated GHD (IGHD, 81 cases) or multiple pituitary hormone deficiency (MPHD, 40 cases). Of 81 IGHD patients, 50 were at prepubertal and 22 at pubertal age, while 9 had a delayed onset of puberty. Out of 40 MPHD patients, 25 were at prepubertal age and 15 at the age of puberty. RESULTS Pituitary hypoplasia, defined as a gland with a height of less than -2 SD for age, was observed more frequently in prepubertal (66%) than pubertal (18%) IGHD patients. It was also found in the majority of MPHD patients of prepubertal (76%) and pubertal age (80%), and of IGHD patients with delayed onset of puberty (100%). Mean+/-SEM pituitary height was significantly lower(P <0.001) in both prepubertal IGHD (-2.70+/-0.20 SD) and MPHD children (-3.10+/-0.39 SD) than in IGHD patients with normal onset of puberty (-1.55+/-0.2 SD). A significantly greater pituitary height was observed in IGHD patients with normal onset of puberty (-1.55+/-0.20 SD) than in MPHD patients at the age of puberty (-4.38+/-0.61 SD, P <0.001) and in IGHD subjects with delayed onset of puberty (-4.06+/-0.41 SD, P <0.001). An important increase (P <0.02) in the height of the pituitary gland was found in 6 of the 9 patients with delayed puberty when they were re-evaluated after completing their spontaneous pubertal development. The frequency of other MRI abnormalities (PPE, stalk transection) was significantly higher in MPHD patients than in IGHD patients (P <0.001). CONCLUSION Our results confirm the usefulness of MRI in the evaluation of children affected by GH deficiency. The association of gland hypoplasia with other MR abnormalities could suggest the presence of multiple anterior pituitary deficiencies. Finally, puberty seems to play an important role in the increase of pituitary size in multiple pituitary hormone deficiency and isolated GH deficiency patients.