Biliary Atresia

  • Etiology:
    — Perinatal (Acquired) is 80% of cases and is due to inflammation causing destruction of fully formed biliary ducts
    — Embryonic (Fetal) is 20% of cases
  • Imaging: Absence of biliary tree
  • Imaging US:
    — Gallbladder is absent to atretic (less than 15-19 millimeters in length
    — Triangular cord sign of triangular-shaped echogenic tissue anterior to portal vein which represents obliterated fibrous ductal remnant with thickening near bifurcation of portal vein that is positive if greater than 3-4 millimeters but is difficult to identify
    — Nonvisualization of common bile duct
    — Hypertrophied hepatic artery
    — Increased liver stiffness on elastography
  • Imaging HIDA scan:
    — Pretreat with phenobarbital for 1 week to optimize liver uptake
    — Decreased uptake of radiotracer in liver
    — No excretion of radiotracer into biliary tree or bowel
  • DDX: Neonatal hepatitis
  • Complications:
  • Treatment: Kasai hepatic portoenterostomy – resect biliary remnant and creat Roux-en-Y intestinal anastomosis within 60 days to prevent liver fibrosis and failure
  • Clinical:
    — Most common cause of neonatal cholestasis
    — Most common cause of liver transplantation in children
    — Clinical triad is jaundice, acholic stool, dark urine
    — Preduodenal portal vein (60%)
    — Interrupted inferior vena cava (40%)
    — Cardiac anomalies (50%)
    — Embryonic (Fetal) type associated with heterotaxy (50%) and thus polysplenia or asplenia and malrotation

Radiology Cases of Biliary Atresia

hepatobiliary scintigraphy scan of biliary atresia
Immediate image (upper left) from a hepatobiliary scintigraphy exam performed after pre-treatment with phenobarbital shows good uptake of radiotracer in the liver with the 24 hour delayed image (upper right) showing no excretion of radiotracer into the bowel. Transverse US of the liver (lower left) shows the presence of a gallbladder. AP image of an intraoperative cholangiogram shows a dilated gallbladder (with some contrast extravasation outside of the gallbladder) and minimal visualization of the intrahepatic biliary tree and no visualization of the extrahepatic biliary tree.
Hepatobiliary scan of biliary atresia
Transverse US of the liver (above) at the level of the main portal vein shows the liver and intrahepatic and extrahepatic biliary tree to be unremarkable. The gall bladder (not shown) was small and collapsed, although the patient had been fasting for 12 hours before the exam. Serial images from a hepatobiliary scan performed after pretreatment with phenobarbital obtained up to 5 minutes after the injection of radiotracer (below left) show prompt uptake of radiotracer by the liver but no excretion of radiotracer into the biliary tree, gall bladder, or bowel. Delayed image obtained at 24 hours after injection of radiotracer (below right) again fails to show excretion of radiotracer into the biliary tree, gall bladder, or bowel.

Nuclear medicine HIDA scan of biliary atresia
AP images from a HIDA scan performed after pretreatment with phenobarbital show good hepatic uptake at 5 minutes after radiotracer injection (above left) without visualization of the biliary tree or gallbladder or small bowel on images obtained at 6 hours (above right) or at 24 hours (below) after injection.