The main pancreatic duct is normally visible on ultrasound as a thin echogenic line through the pancreatic body, measuring up to 3 mm in diameter. Dilation (>3 mm) suggests obstruction from a ductal stone, stricture, or mass. A dilated pancreatic duct in conjunction with a dilated CBD (double duct sign) is a highly suspicious finding for pancreatic head carcinoma or ampullary malignancy. Pancreatic duct dilation is also seen in chronic pancreatitis, often with parenchymal calcifications and irregular duct contour.