Value of nuclear magnetic resonance tomography in the diagnosis and therapy outcome of prolactinomas

: 30 MR tomographies were performed in 15 patients suspected of having a prolactinoma on account of clinical examinations and test in the chemical laboratory. The T1 and T2 times of the adenomas were determined quantitatively. In addition, high resolution CT imaging had been performed in all patients. The signal performance of the normal pituitary gland determined in 11 healthy persons on the basis of quantitatively measured T1 and T2 times, was found to largely correspond with that of grey matter of the brain. Of the 14 confirmed prolactinomas, 11 were microadenomas and 3 macroadenoma. Solid adenomas were identified by enhanced T1 values. It was possible to differentiate these from cystic, haemorrhagic and necrotic tumour components by differences in signal performance. 7 patients on drug therapy with dopamine agonists were controlled by means of MR tomography. No measurable size reduction of tumour was seen in 3 patients with cystic or haemorrhagic tumour components. On the other hand, tumour reduction was seen after brief drug therapy in 2 macroprolactinomas and one microprolactinoma. An essential advantage offered by MR is, besides the absence of exposure to radiation, in the first place the better and more precise information on the relative position of the adenoma with reference to the vessels and the optic chiasm, and, secondly, better identification of cystic and haemorrhagic processes within the prolactinoma.