Effectiveness of Contrast-Enhanced Ultrasonography for the Characterization of Small and Early Stage Pancreatic Adenocarcinoma.

The purpose of this retrospective study is to evaluate the effectiveness of contrast-enhanced ultrasonography for the characterization of small and early stage pancreatic adenocarcinoma. Contrast-enhanced ultrasonography and contrast-enhanced computed tomography (CT) were performed in 200 cases, with pancreatic hypoechoic regions detected with ultrasonography. Assuming that hypo-enhancement was indicative of pancreatic adenocarcinoma, the sensitivity of each imaging modality was calculated. The sensitivities of contrast-enhanced ultrasonography and contrast-enhanced CT to characterize adenocarcinoma were 97.0% and 77.0% (p < 0.0001) for all 100 adenocarcinoma cases, 100% and 76.7% (p = 0.0016) for 43 small (≤20 mm) cancers, 100% and 58.3% (p = 0.0253) for 12 smaller (≤10 mm) cancers and 100% and 72.2% (p = 0.0016) for 36 stage IA cancers, respectively. The sensitivity of contrast-enhanced ultrasonography was sufficiently high and significantly superior to that of contrast-enhanced CT. Contrast-enhanced ultrasonography is a sensitive tool for selecting highly possible pancreatic adenocarcinoma lesions without overlooking early stage tiny adenocarcinomas among a large number of hypoechoic lesions detected with ultrasonography.