Current status of abdominal pancreatic ultrasound. A retrospective analysis of 585 pancreatic ultrasound examinations

BACKGROUND: In the recent years several investigations focused on the diagnostic value of abdominal ultrasonography in pancreatic disorders. However, the diagnostic accuracy in these studies ranged between 40 and 90% probably related to variations in study design and other methodologic criteria. PATIENTS: We examined retrospectively 585 patients subdivided into six subgroups. 385 patients had a clinical question aimed at the pancreas and the remaining 200 functioned as screening patients. RESULTS: Using laboratory tests, CT, ERCP, surgery and autopsy as reference methods the positive predictive value for all pancreatic disorders was 85% with the best results for chronic pancreatitis (86% versus 77.5% for acute pancreatitis and 79.5% for malignant tumors). The prevalence of pancreatic disease in symptomatic patients was 28.6% versus only 2.5% in the screening groups. Therefore no significant differences could be detected in groups where the pancreas was not clearly visualized and groups with negative sonographic findings (4% false negative findings versus 1%, respectively). In groups with suspected pancreatic disease the negative predictive value was 86% which was independent of the visualization of the pancreas. CONCLUSION: In summary positive sonographic findings have a high predictive value for pancreatic disorders and negative results are not more reliable than missing visualization of the pancreas. The positive predictive value is independent from the kind of pancreatic disease and in screening examinations negative findings and findings without clearly visualization of the pancreas have both high negative predictive values.