Localization of pancreatic insulinomas with MR imaging at 0.5 T.
OBJECTIVE
To determine the role of MR imaging in the localization of pancreatic insulinomas in patients with clinical and laboratory diagnosis of insulin-producing tumor.


METHODS
Thirty-one patients presenting with signs and symptoms of pancreatic insulinomas were prospectively included in our study. Twenty-six patients underwent surgery, and pathologic specimens were examined: 5 patients, in whom the initial diagnosis of insulinoma was excluded, were also studied and then followed up. All patients were studied with a high gradient power 0.5 T magnet. Images were evaluated by 2 radiologists blinded to previous investigations, tests and results.


RESULTS
MR imaging correctly localized 24 of the 26 insulinomas (2 were false-negative and 1 false-positive) and was correctly negative in the 5 control patients. The interobserver agreement had a kappa value of 0.89.


CONCLUSIONS
MR imaging was accurate in localizing pancreatic insulinomas and as a consequence, patients in our institution are now submitted to surgery directly after the MR examination. Invasive methods are considered only in cases in which, despite clear biochemical results, MR imaging has not demonstrated a pancreatic focal lesion.
Catalano
C
C
Department of Radiology, II Chair, University of Rome La Sapienza, Italy.
Pavone
P
P
Laghi
A
A
Panebianco
V
V
Fraioli
F
F
Pediconi
F
F
Napoli
A
A
Passariello
R
R
D000293:Adolescent; D000328:Adult; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007340:Insulinoma / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016896:Treatment Outcome