The transverse common duct.
The sonographic appearance and incidence of transverse common ducts were studied. A review of 118 intraoperative cholangiograms showed a transverse segment longer than 35 mm in 18% of the dilated extrahepatic ducts and in 6% of the normal caliber ducts. The causes of obstruction varied. When dilated, the transverse segment may be confused with the portal and splenic veins on a sonogram. An awareness of this anatomic variation can be helpful in locating an obstructing lesion of the extrahepatic bile duct.
D014670:Ampulla of Vater / Q000000981:diagnostic imaging; D001659:Biliary Tract / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D002277:Carcinoma / Q000175:diagnosis; D002758:Cholangiography; D001651:Cholestasis, Extrahepatic / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003137:Common Bile Duct Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003138:Common Bile Duct Neoplasms / Q000175:diagnosis; D042882:Gallstones / Q000175:diagnosis; D006801:Humans; D010190:Pancreatic Neoplasms / Q000175:diagnosis; D014463:Ultrasonography