Purpose: Previous studies have suggested that the hypopituitarism following traumatic brain injury (TBI) is more prevalent than traditionally thought. The objective of this study was to characterize longitudinal MRI morphometric changes of pituitary gland in patients with severe TBI.Materials and methods: Fourteen patients who had suffered a severe TBI (Glasgow Coma Score=3 - 8) underwent MRI at three time points: Time 1 (mean=31. 5 days), Time 2 (98. 0) and Time 3 (185. 5). The pituitary gland volume was quantified by manually tracing on T1-weighted magnetic resonance images. Data from TBI patients were compared to 14 age- and sex-matched uninjured controls. The relationships between pituitary volumetric measures and patient demographics, length of respiratory support and coma, and presence of intracranial hemorrhage or skull fractures were also analyzed.Results: Following TBI, the pituitary volumes were significantly greater at all three time points: Time 1: median=665mm3, range=460-830mm3, p=0. 007; Time 2: 694mm3, 467-866mm3, 0. 007; and Time 3: 655mm3, 444-795mm3, 0. 015, compared with controls (504mm3, 433-591mm3). At Time 1, pituitary volume was increased in 10 out of 14 patients. Of these, early pituitary enlargements persisted up to six months in nine patients. Pituitary enlargements were negatively correlated with GCS, but not with other variables.Conclusion: Following a severe TBI, early pituitary enlargement found in most of our patients persisted in the chronic phases. Our data suggest a potential role of MRI morphometry in early prediction of pituitary dysfunction following head trauma, but further studies including hormonal measurements are necessary for validation
