OBJECTIVETo evaluate prospectively the efficacy and clinical significance of ultrasonography (US), helical computed tomography (HCT), endoscopic ultrasonography (EUS) and magnetic resonance imaging (MRI) in assessing locoregional invasion to the surrounding tissue or organs of primary pancreatic carcinoma.

METHODSSixty-eight consecutive patients with pancreatic carcinoma underwent US, HCT, EUS and MRI examinations before surgical exploration. All imaging results in terms of tumor size and locoregional invasion were assessed separately by two diagnostic radiologists and compared with the surgical and pathological findings.

RESULTSAmong the HCT, US, EUS and MRI examinations, EUS had the highest accuracy in assessing tumor size with a regression coefficient for the maximal and minimal diameter of 1.0250 (P = 0.0426) and 0.9873 (P < 0.0001), respectively. In the assessment of locoregional invasion to the surrounding tissue or organs, EUS also had the highest accuracy (75.8%) and sensitivity (80.0%), but MRI had the highest positive predicting value (97.4%). None of these four imaging techniques was significantly correlated with the surgical findings when analyzed by univariate logistic regression.

CONCLUSIONEndoscopic ultrasonography may be the most useful imaging technique in assessing tumor size, but for assessing loco-regional invasion of primary pancreatic carcinoma, combination of more than one imaging techniques may be necessary.