Evaluation of three-dimensional MRI exploration of prolactin-secreting microadenomas.
Over an 8-month period (July 1990-to February 1991), we explored 21 women presenting with a clinical and laboratory profile of prolactin-secreting microadenoma of the pituitary gland. Magnetic resonance imaging (MRI) is undoubtedly the most efficient method to explore microadenomas, especially when carried out in the absence of any treatment. In 8 cases, MRI was performed in the absence of medical treatment and gave a positive result, i.e. always showed a focal lesion. In the remaining 13 cases the patients had been treated before the exploration, and MRI detected a microadenoma in only 4 cases. The duration of treatment and the time elapsed between its withdrawal and the MRI examination did not seem to influence the positivity or negativity of the imaging results. Among the 9 cases where MRI failed to show a focal lesion, the image was normal in 3 cases and displayed an arachnoidocele in 3 cases; the pituitary gland was convex and homogeneous in 1 case and convex and heterogenous in 3 cases, which raised the problem of the effects of bromocriptine on the MRI images. As regards signals, in 5 cases the microadenoma was hyperintense on the spin-echo sequence without contrast injection; it was undetectable on the same sequence in 2 cases. In 4 cases the lesion was contrast-enhanced after gadolinium injection. Using millimetric sections enables small-size adenomas (2.5 x 3 mm) to be visualized.
Girard
N
N
Service de Radiologie, Hôpital Nord, Marseille.
Cortesi
L
L
Chabert-Orsini
V
V
Maman
P
P
Brue
T
T
Jaquet
P
P
Raybaud
C
C
D000293:Adolescent; D000328:Adult; D001099:Arachnoid / Q000473:pathology; D001971:Bromocriptine / Q000627:therapeutic use; D003287:Contrast Media; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D011388:Prolactin / Q000097:blood; D015175:Prolactinoma / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology
D003287:Contrast Media; D001971:Bromocriptine; D011388:Prolactin; D005682:Gadolinium