Pituitary magnetic resonance imaging in normal human volunteers: occult adenomas in the general population.
OBJECTIVE
To determine the prevalence of focal lesions of the pituitary gland that suggest the presence of a pituitary adenoma in asymptomatic persons.


METHODS
100 normal volunteers (70 women, 30 men; age range, 18 to 60 years old) were studied by high-resolution magnetic resonance imaging (MRI) of the pituitary gland before and after administration of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA).


METHODS
Occult pituitary adenomas are identified at autopsy in 3% to 27% of unselected asymptomatic patients. The frequency of incidental pituitary adenomas detected by MRI in normal persons is unknown.


METHODS
The MRI scans from volunteers were randomly mixed with scans of 57 patients with Cushing disease and interpreted independently by three blinded reviewers.


RESULTS
Seven women (10%) and three men (10%) had focal areas of decreased signal intensity in the pituitary gland after administration of Gd-DTPA. The lesions ranged from 3 to 6 mm in greatest diameter and were diagnosed as pituitary adenomas by at least two of the three reviewers. When similar lesions were detected on MRI scans in patients with Cushing disease, the positive predictive value for identification of an adenoma at that site was 86%.


CONCLUSIONS
About 10% of the normal adult population have pituitary abnormalities on MRI scans that are compatible with the diagnosis of asymptomatic pituitary adenomas. Most pituitary adenomas remain asymptomatic and do not require treatment.
Hall
W A
WA
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
Luciano
M G
MG
Doppman
J L
JL
Patronas
N J
NJ
Oldfield
E H
EH
D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D003287:Contrast Media; D003480:Cushing Syndrome / Q000175:diagnosis; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D010902:Pituitary Gland / Q000033:anatomy & histology* / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D012016:Reference Values; D016037:Single-Blind Method
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA