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IMAGE INTERPRETATION · HEPATOBILIARY AND GI

Biliary Atresia on Neonatal HIDA Scan

Tc-99m HIDA scan (5–50 min and 4 hr) showing hepatic uptake with absent biliary excretion into bowel — pattern of biliary atresia
Tc-99m HIDA scan (5–50 min and 4 hr) showing hepatic uptake with absent biliary excretion into bowel — pattern of biliary atresia

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Question

A Tc-99m HIDA scan is performed in a jaundiced neonate to differentiate biliary atresia from neonatal hepatitis. The scan shows good hepatic uptake but NO excretion into the biliary system or bowel on 24-hour images. This pattern is MOST consistent with:

  1. ANeonatal hepatitis — diffuse hepatocellular dysfunction impairs IDA tracer processing, causing globally reduced hepatic extraction and delayed or diminished biliary excretion that may eventually appear on 24-hour images after phenobarbital pretreatment
  2. BNormal neonatal liver maturation — physiologic immaturity of hepatocyte organic anion transport (OATP1B1/B3 isoforms) transiently delays biliary IDA excretion until 6–8 weeks of age, mimicking pathologic obstruction on early imaging
  3. CBiliary atresia — absent biliary excretion into bowel despite hepatocyte uptake indicates complete biliary obstruction
  4. DCholedochal cyst — focal fusiform or cystic dilatation of the common bile duct creates a photopenic defect on delayed imaging with pooling of tracer within the cyst and eventual slow bowel transit, distinguishable from atresia by late excretion
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C. Biliary atresia — absent biliary excretion into bowel despite hepatocyte uptake indicates complete biliary obstruction

HIDA scan is a key test for differentiating biliary atresia (BA) from neonatal hepatitis in jaundiced neonates: (1) In BILIARY ATRESIA: hepatocyte function is initially preserved (good hepatic uptake), but the obliterated bile ducts prevent any biliary excretion — absent bowel activity on 24-hour images despite hepatocyte uptake. (2) In NEONATAL HEPATITIS: hepatocyte function is impaired (poor or delayed hepatic uptake), but the biliary tree is patent — some delayed bowel activity may eventually appear. Pretreatment with phenobarbital (5 mg/kg/day × 5 days before scan) enhances bile production and improves test specificity. Absent bowel activity in BA is 100% sensitive; the Kasai procedure (hepatoportoenterostomy) must be performed before 60 days of age for best outcomes.

More hepatobiliary and gi images

Tc-99m RBC scan (ANT 60 min, sequential frames) — focal activity appearing in the right lower quadrant and migrating along the colon, indicating active GI hemorrhageActive Lower GI Bleed on Tagged RBC Scan Tc-99m mebrofenin hepatobiliary scan: 12 sequential frames over the first hourNormal Hepatobiliary Scan Sequence (Mebrofenin) Tc-99m mebrofenin hepatobiliary scan: 12 sequential frames over the first hourPatient Preparation for a HIDA Scan Dynamic abdominal scan: sequential frames at 3 min/frame from 30 to 60 minutes post-injectionMeckel’s Diverticulum Scan with Tc-99m Pertechnetate Tc-99m HIDA scan post-morphine augmentation (2-minute frames, 0–70 min) — absent gallbladder filling despite biliary excretion, consistent with acute cholecystitisAcute Cholecystitis on HIDA Scan with Morphine Tc-99m HIDA with CCK infusion (LAO15, 4 min/frame) — gallbladder fills but GBEF = 22% at 59 min, consistent with biliary dyskinesiaLow Gallbladder Ejection Fraction on CCK HIDA
← Low Gallbladder Ejection Fraction on CCK HIDAActive Lower GI Bleed on Tagged RBC Scan →

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