MR imaging of prolactin-secreting microadenomas.
Eight proven and three presumed prolactin-secreting microadenomas were studied with magnetic resonance (MR) imaging. All 11 cases had CT evidence of a tumor. Technical factors for MR included use of 1.3-1.5 T MR systems, 3 mm slice thickness, short repetition time (TR) (T1-weighted) and long TR (T2-weighted) spin-echo pulse sequences. Six microadenomas were demonstrated with MR. Four tumors had a long T1 and long T2, one had a long T1 and short T2, and one bromocriptine-treated tumor had a short T1 and short T2. MR failed to delineate the focal mass within the pituitary gland in the other five patients. The cause of the MR failures was not determined; however, tumor size did not appear to be a factor. MR signals arising from microadenomas are variable and possibly related to the activity of the prolactin-secreting cells. Correlation of findings from MR imaging, spectroscopy, and electron microscopy may lead to an understanding of the variable MR appearance of microadenomas.
Pojunas
K W
KW
Daniels
D L
DL
Williams
A L
AL
Haughton
V M
VM
D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D010911:Pituitary Neoplasms / Q000175:diagnosis*; D011388:Prolactin / Q000378:metabolism*
D011388:Prolactin