Contrast-enhanced ultrasound in the staging of acute pancreatitis.

Abstract

To determine the diagnostic value of contrast-enhanced ultrasound (CEUS) in the assessment of acute pancreatitis, with computed tomography (CT) as the reference standard. Fifty consecutive patients (mean age 58.4 years; range 23-86 years) with acute pancreatitis underwent prospectively both CT and ultrasonography, including CEUS, within a 24-h interval. Pancreatic vascularisation was evaluated with CEUS after injection of a second-generation US contrast-enhancing agent. Acute pancreatitis severity was graded according to the Balthazar index. The results were compared with CT severity index and clinical outcome by using Spearman's correlation coefficient. A significant correlation between CT and CEUS was found for the CT severity index (r = 0.926), extent of necrosis (r = 0.893) and Balthazar grade (r = 0.884). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting severe acute pancreatitis based on CT findings (severity index greater than 3 and/or presence of necrosis) were respectively 91%, 100%, 100% and 83%. A significant correlation between CEUS severity index and clinical variables was found: Ranson score (r = 0.442), C-reactive protein (CRP) levels 48 h after admission (r = 0.385) and length of hospital stay (r = 0.362). CEUS is comparable to CT in detecting pancreatic necrosis as well as predicting its clinical course. Therefore, when CT is contraindicated CEUS may be a valid alternative.