[Imaging of pituitary adenomas].

In cases of pituitary hormone hypersecretion, magnetic resonance imaging (MRI) can demonstrate the causal lesion, which is often small (microadenoma). In pituitary adenomas with suprasellar extension, MRI shows the tumor's relation to the surrounding structures: the optic chiasm, the internal carotid artery, the sphenoidal sinus, etc. MRI usually makes it possible confirm or rule out any cavernous sinus invasion by the pituitary adenoma, a determination essential for planning treatment. After pituitary surgery, MR imaging is again essential for visualizing any residual tumor tissue and - if the MRI is carefully performed to be reproducible - for assessing its development over time.