Perinatal abnormalities and subhypothalamic bright spot on magnetic resonance imaging in pituitary dwarfs.

Sir .—The survey results on magnetic resonance imaging (MRI) in patients with idiopathic pituitary dwarfism as reported by Root et al 1 were interesting and warrant further observations. The authors demonstrated that MRI in two patients with pituitary dwarfism without asphyxia at birth (one had panhypopituitarism with intact posterior function, and the other had central hypothyroidism) had a signal of high intensity near the optic tract. 2,3 A small pituitary gland and an unclear defined pituitary stalk were also observed. 4 To ascertain that the hypopituitary state was a result of an insult to the pituitary stalk, we compared the T 1 -weighted MRI findings of the hypothalamic-pituitary structure in two groups, a total of 14 patients, of idiopathic pituitary dwarfs. The two groups were the following: those with perinatal abnormalities were group 1 (5 boys and 2 girls) (6 had had asphyxia at birth and 1, dystocia with vacuum