HYPOPHYSITIS - ENDOCRINOLOGIC AND DYNAMIC MR FINDINGS

PURPOSE: Our purpose was to assess the worth of dynamic MR imaging in the evaluation of vascular changes of the pituitary in patients with l ymphocytic hypophysitis, METHODS: Five patients (four males, one femal e; 9 to 53 years old) with lymphocytic hypophysitis or infundibuloneur ohypophyitis were studied, All patients underwent endocrinologic studi es and a series of two to five MR examinations performed over a period of 8 months to 5 years, including a total of nine dynamic imaging stu dies, RESULTS: Two patients had panhypopituitarism and three had parti al hypopituitarism. Diabetes insipidus was present in four patients, A mong the five patients, the pituitary was enlarged in three, of whom t wo showed improvement on follow-up MR studies, Three patients had a th ickened stalk, which improved on subsequent examinations, In all nine dynamic studies, the enhancement time of the whole pituitary was delay ed to over 90 seconds, even though five of the nine conventional, simu ltaneously performed MR studies showed a normal pituitary, The peak ti me of posterior pituitary enhancement in the first dynamic study was a lso delayed in all patients (from 60 to 120 seconds), In two patients, normal early enhancement of the posterior pituitary was identified on initial studies but not on subsequent studies, CONCLUSION: Dynamic MR imaging can display an abnormality of the hypophysial vasculature eve n if the pituitary disease is seen to regress on the conventional MR s tudy, The delay or even the lack of early enhancement of the posterior pituitary in lymphocytic hypophysitis may be due to secondary inflamm atory changes.