Gallbladder

Adenomyomatosis

• Accumulation of cholesterol crystals in gallbladder with formation of GB wall out-pouchings called Rokitansky-Aschoff sinuses

• Comet-tail artifact is highly suggestive of diagnosis

  • Looks like a dot with streaky line following it

• 3 types - doesnt really matter although

  • Hourglass gallbladder = cholesterol granules and sinuses accumulate symmetrically on each side of GB wall pushing the walls inward to look like an hourgalass

    • Seen in segmental form

Biliary Ductal dilatation

• On US can differentiate from vessels by putting on doppler

  • Biliary ducts will have no flow

• Dilatation

  • >2mm for intrahepatic ducts

  • >6mm for extrahepatic ducts

  • > 10mm (1.0 cm) for extrahepatic ducts if had cholecystectomy

Hepatolithiasis

• Stone in intrahepatic biliary duct

• Causes

  • Primary sclerosing cholangitis

  • Recurrent pyogenic cholangitis

  • Biliary anastomosis

Primary Sclerosing cholangitis

• Multifocal structures of the intra and extrahepatic biliary ducts

• Increased risk for cholangiocarcinoma

• Associated with ulcerative colitis

• Findings

  • US

    • Biliary wall thickening

    • Biliary strictures

Pneumobilia

• Air in biliary tree

• Findings

  • US

    • Linear hyperechoic structures

    • Dirty shadowing

• DDX

  • Recent procedure

  • Sphincter of Oddi dysfunction/incompetence

  • Fistula

  • Infection

Acute Cholecytitis

• Dilation, inflammatory changes of the GB

• Tensile Gallbladder Wall sign

  • Distended GB causes mass effect on the abdominal wall causing the abdominal wall to bow outward

Klatskin Tumor (Hilar Cholangiocarcinoma)

• Typically at bifurcation of common bile duct

• Findings

  • Intrahepatic biliary ductal dilation

  • Mass at liver hilum

Choledochal Cysts

• 5 Flavors

• Type 1

  • Most common

  • 1A - diffuse - involve entire extrahepatic biliary ducts

  • 1B - focal - involve segment of extrahepatic biliary duct

  • 1C - fusiform - only affect CBD

• Type 2

  • Extrahepatic biliary duct diverticula

• Type 3

  • Choledococele = ectasia of CBD segment

• Type 4

  • Multiple intrahepatic and extrahepatic aspects

• Type 5

  • Caroli disease = congenital cystic dilatation of the intrahepatic biliary ducts

Biliary Cystadenocarcinoma

• Multiseptate liver mass

• Proteinacous fluid content better seen on MR than CT (see different signal on MR not seen on CT basically)

• Cannot really be differentiated fro biliary cystadenoma on imaging alone

  • Nodularity of septa suggests malignancy