Localizing insulinomas with combined radiographic methods.

Twenty-one patients with hyperinsulinism were studied to localize the source of the insulin production. Nineteen patients had pancreatic tumors and two patients studied after pancreatectomy had hepatic metastases. Of the 19 pancreatic tumors, 16 were identified by angiography. CT found six tumors in 14 patients studied while sonography correctly localized only three of 12 tumors. Neither CT nor sonography was positive in those patients with a negative arteriogram. Noninvasive imaging methods can localize large tumors and may be useful for detecting hepatic metastases. Angiography, however, remains the most accurate method for detecting smaller lesions.