Changes

On '''[[ultrasonography of the biliary tract]]''', the width of the duct is usually easiest for the perihilar bile duct (which is the region where the common hepatic duct becomes the common bile duct, at the hilum of the liver). A normal width of the perihilar bile duct can be reported as for the extrahepatic bile ducts, since it also excludes a more distal common bile duct obstruction. The common bile duct is normally up to 8 mm.<ref name="HoeffelAzizi2006">{{cite journal|last1=Hoeffel|first1=Christine|last2=Azizi|first2=Louisa|last3=Lewin|first3=Maité|last4=Laurent|first4=Valérie|last5=Aubé|first5=Christophe|last6=Arrivé|first6=Lionel|last7=Tubiana|first7=Jean-Michel|title=Normal and Pathologic Features of the Postoperative Biliary Tract at 3D MR Cholangiopancreatography and MR Imaging|journal=RadioGraphics|volume=26|issue=6|year=2006|pages=1603–1620|issn=0271-5333|doi=10.1148/rg.266055730}}</ref>

<gallery>

File:Ultrasonography of dilated intrahepatic bile ducts.jpg|Dilated intrahepatic bile ducts.<ref>{{cite journal|last1=Yoo|first1=Youngsun|last2=Mun|first2=Seongpyo|title=Synchronous double primary squamous cell carcinoma and adenocarcinoma of the extrahepatic bile duct: a case report|journal=Journal of Medical Case Reports|volume=9|issue=1|year=2015|issn=1752-1947|doi=10.1186/s13256-015-0600-1}}</ref>