CT scan of pituitary adenomas.

CT scan is an extremely useful, almost harmless means of diagnosing pituitary adenomas. Growth hormone (GH)-secreting adenomas tent to have higher absorption coefficient on plain CT than the nonfunctioning and prolactin (PRL)-secreting adenomas. The absorption coefficient on contrasting enhanced CT does not identify the specific type of adenoma. Ring-like enhancement was observed in five nonfunctioning and four PRL-secreting adenomas with suprasellar extension, while cystic components were observed in four nonfunctioning and four PRL-secreting adenomas. In three of ten cases of PRL-microadenomas, the site corresponding to the adenoma was not enhanced, whereas the normal pituitary was. A correlation exists between the size of PRL-secreting adenoma and the serum PRL level, but not between the size of GH-secreting adenomas and the serum GH level.