<prompt> Linear filling defect on ERCP is characteristic of -Bile duct stonePancreatic duct stoneWorm in biliary treeStricture  <response>: Ans. is c i.e., Worm in biliary tree Imaging in ascariasiso Plain abdominal X ray: calcified worm,o USG: moving echogenic structures or strips,o ERCP: linear filling defect. 