Assessment of portal vein invasion in pancreatic cancer by fusion 3-dimensional ultrasonography

Objective. The purpose of this study was to assess the usefulness of a newly developed imaging technique, fusion 3-dimensional ultrasonography (3DUS) in the diagnosis of portal vein (PV) invasion in patients with pancreatic cancer (PC). Methods. Fourteen patients with proven PC were examined by fusion 3DUS presented as shaded volume-rendering and multiplanar reconstruction images. The surgical findings were obtained in all patients (12 with resection and 2 without). The findings were compared with those of 2-dimensional ultrasonography (2DUS), contrast-enhanced computed tomography (CT), dynamic CT (DCT), angiography, and surgical findings. Portal vein invasion was assessed by 3 independent radiologists for each modality, and objectivity of the assessment was examined by interobserver variability analysis (K value). Results. On the basis of surgical findings, the accuracy rates of 2DUS, fusion 3DUS, DCT, and angiography were 78.6%, 92.9%, 85.3%, and 66.7%, respectively. The K values of 2DUS, fusion 3DUS, DCT, and angiography for PV invasion were 0.57, 0.90, 0.63, and 0.49, respectively, being most objective in fusion 3DUS. Conclusions. Fusion 3DUS is useful for diagnosis of PV invasion of PC.