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.