Hepatobiliary scintigraphy for early diagnosis of biliary atresia.

Introduction: The aim of this study was to evaluate the validity of (99m)Technetium-trimethylbromo-iminodiacetic acid hepatobiliary scintigraphy (HS) for the diagnosis of biliary atresia (BA).
Methods: From January 2005 to December 2009, a total of 47 infants with conjugated hyperbilirubinaemia (> 20 micromol/l total bilirubin of which 20% is conjugated) underwent HS. BA was suspected if no tracer was visualised in the gut 24 hours post-injection. The results of the HSs were compared with the gold standard, laparotomy with antegrade cholangiography findings.
Results: Considering the final diagnosis based on the gold standard, the sensitivity, specificity, positive predictive value and negative predictive value (NPV) of the HS in the diagnosis of BA was 100%, 63.6%, 53.8%, and 100%, respectively. The accuracy was 74.5%. BA patients with non-draining HS had significantly higher levels of gamma-glutamyl transpeptidase (GGTP) than non-BA patients with non-draining HS (p = 0.019) or draining HS (p = 0.0001).
Conclusions: HS plays an important role in the diagnostic strategy of infantile jaundice due to conjugated hyperbilirubinaemia. It is a non-invasive method that only seldomly calls for sedation. A high sensitivity and NPV prevent un-necessary surgery. Because of the low specificity of HS in diagnosing BA, it should be part of a multimodality imaging strategy when the result supports a clinical suspicion of BA. In cases with non-draining HS and normal GGTP blood levels, supplemental imaging modalities are especially needed.
Funding: none.
Trial Registration: not relevant.