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.
Pediatric Imaging 