RESUMO
Objective To assess the clinical value of low-frequency mini - probe sonography ( LFMPS) in preoperative localization of pancreatic endocrine tumors comparing with other imaging methods. Methods Twenty one cases with suspected pancreatic endocrine tumors were enrolled from June 2000 to June 2002, we compared the diagnostic results of LFMPS, transcutaneous ultrasonography ( US) , helico-computed tomography ( HCT) and magnetic resonance imaging (MRI) with surgical localization and histopathological results by using Fujinon 7. 5 MHz miniature probe and SP-701 ultrasonic system. Results Sixteen pancreatic insulinomas and 1 extra pancreatic VIPoma (vesoactive intestinal polypeptide tumor) were confirmed by surgery and histopathological examination in 17 of the 21 patients, and the rest 4 patients didn't receive surgical procedure because of the negative results in all imaging studies. Among pancreatic lesions, they located on head, body and tail in 9, 3 and 4 cases respectively; the average diameter of all 17 lesions was 2. 02cm. LFMPS correctly localized the tumor in 14 of 17 patients (82. 4% ) while CT in 15 of 17 patients (88. 2% ) , MRI in 12 of 17 patients (70. 6% ) and US in 9 of 17 patients (52. 9% ). Besides, the diagnostic accuracy of LFMPS in detection of small size (