Background: Magnetic resonance imaging (MRI) has proved to be an accurate method to show neuroanatomical changes in the pituitary gland. Thus it has become one of the basic investigations in patients with hypopituitarism. In most of these patients growth hormone deficiency is present either as an isolated form (IGHD) or multiple hormone deficiency (MPHD) of the pituitary gland. The aim of MRI is firstly to rule out an invasive etiology of hypopituitarism, but recently there is an evidence, that MRI may play a role in predicting functional characteristics of the disease and may also help to select a subgroup of genetic base etiology. Aim: To evaluate the role of MRI in predicting etiology and prognosis of hypopituitarism in patients treated for pituitary deficiency. To follow up the relationship between hormone deficiency and morphology of the hypophysis. Patients and methods: Retrospective study of 44 hypopituitary children who had undergone MRI. All patients had growth hormone (GH) deficiency proved by at least two tests. According to the peakGH response, the patients were assorted as having mild or severe GHD. By examining levels of LH, FSH, TSH, fT4 and cortisol the group was divided into IGHD and MPHD. Chi-square test was used to evaluate the results. Results: Pathology on the MRI scan was found in 16 of 29 patients with IGHD (55 %) an in 14 of 15 MPHD patients (93 %), p < 0.01. SevereGHdeficiency was present in 73%of all patients and there wereMRI abnormities in 81 % of this subgroup, whereas in mild GHD patients (27%of all patients) pathology on MRI was detected in 33 %, p < 0.004. Concerning personal history there were MRI abnormities found in 4 of 5 children with breech delivery, in all 5 children with perinatal hypoxia, in 4 patients with a brain tumour and 1 patient with head trauma. Conclusions: Pathologic MRI scan in hypopituitarism is an essential factor of functional hypopituitary deficiency. It identifies a group of patients with increased risk of developing panhypopituitarism. The history of

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