Endocrine Abstracts

Introduction: Previous studies demonstrated a relationship between T1- and T2-weighted signal intensity and tumor growth pattern in pituitary somatotropinomas. The goal of this retrospective study was to analyze the MRI characteristics of pituitary macroadenomas with different hormonal activity in newly diagnosed patients.

Material and methods: Pre-treatment T1- and T2-weighted MR-images (Intera Achieva, PHILIPS, 3.0T) of patients with 42 non-functional adenomas (NFA), 18 macroprolactinomas, 55 somatotropinomas were analyzed, taking into account the intensity of the signals produced by the tumors, as well as their dimensions and growth direction. The results were expressed as M? (25%; 75%).

Results: In NFA group, majority of patients (30/42, 71%) had isointensive T1-signal in the most common combinations with hyperintensive or isointensive T2 (18/42, 42.9 and 9/42, 21.4%, accordingly). NFA’s volumes did not differ between these subgroups. In prolactinoma group 15/18 (83.3%) patients showed hyperintense T2 in the most common combination with isointensive T1 (7/18, 38.9%) and hypointensive T1 (6/18, 33.3%). IsoT1/hyperT2 prolactinomas had bigger volume compared to hypoT1/hyperT2 ones. In somatotropinoma group 43/55 (78.2%) patients had hypointensive T1 in combinations with hypo-, iso- or hyperintensive T2 (22/55, 40%; 12/55, 21.8%; 9/55, 16.4%, respectively). HypoT1/hypoT2 tumors had the smallest volume.

Conclusion: In all type of pituitary tumors hypointensive MR-signal (either T1 or T2) was associated with infrasellar tumor expansion and smaller tumor volume. In contrast, hyperintesive T2 was associated with suprasellar tumor expansion and bigger tumor volume. IsoT1/isoT2 tumors were found only in NFA group; hypoT1/hypoT2 tumors were observed only in somatotropinomas so further investigations should be carried on to prove the diagnostic value of these results. Accurate determination of T1/T2 signal intensity can be used as additional predictors of hormonal and proliferative activity of pituitary tumors.