Encapsulated collection of bile outside biliary tree

Ultrasound

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  Grayscale ultrasound

  
  
  
  
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    Focal collection of fluid within liver or close to biliary tree, or in gallbladder fossa in patients with recent cholecystectomy

    
    
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    Round or oval in shape, usually unilocular, usually no discernible thin capsule

    
    
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    Anechoic fluid content suggests fresh biloma

    
    
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    Debris or septa suggest infected biloma

    
    
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    May see echogenic foci at periphery related to clips from recent surgery

  
  
  
  
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  Color Doppler ultrasound

  
  
  
  
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    No vascularity within lesion

    
    
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    For infected biloma, there may be increased vascularity in adjacent tissue

  
  

CECT: Well-defined or slightly irregular cystic lesion without identifiable wall

Perihepatic collection/seroma/lymphocele

Hepatic cyst

Hepatic abscess

Intrahepatic hematoma

Iatrogenic: Laparoscopic cholecystectomy, post liver transplantation, ERCP or other instrumentation of biliary tree, liver biopsy

Post traumatic: Blunt trauma, motor vehicle accident

Spontaneous rupture of bile duct

Look for low-level echoes within biloma, which can indicate underlying infection