title: Letter: Hub modification to prevent air bubble artifacts during transduodenal ampullary cannulation.
mesh_terms: D014670:Ampulla of Vater / Q000000981:diagnostic imaging*; D001659:Biliary Tract / Q000000981:diagnostic imaging; D002404:Catheterization / Q000009:adverse effects / Q000295:instrumentation*; D004724:Endoscopy; D006801:Humans; D008297:Male; D011859:Radiography