Tc-99m PMT scintigraphy in the diagnosis of pediatric biliary atresia.

Purpose: Hepatobiliary scintigraphy plays an important role in the differentiation of biliary atresia (BA) and non-BA. The usefulness of Tc-iminodiacetic acid (IDA) derivatives in BA diagnosis is reported in several papers. In contrast, there are no comprehensive data on differentiating BA from non-BA using Tc-N-pyridoxyl-5-methyl-tryptophan (PMT). Our objective was to evaluate the usefulness of Tc-PMT scintigraphy in the diagnosis of BA.

Materials And Methods: 52 infants who received Tc-PMT scintigraphy for suspected BA were retrospectively evaluated. Preoperative cholangiograms or follow-ups were used as the gold standard for diagnosis of BA. We analyzed the utility of Tc-PMT scintigraphy, various clinical and investigational parameters in the diagnosis of BA.

Results: The final diagnoses in this group were BA (67.3%) and non-BA (32.7%). Tc-PMT scintigraphy, stool color change, total bilirubin, direct bilirubin, aspartate aminotransferase (AST) and γ-glutamyl transferase (γ-GTP) led to distinguishing between BA and non-BA in univariate analysis. Subsequent multivariate logistic regression analysis indicated that Tc-PMT scintigraphy and γ-GTP were independent predictors of BA. The diagnostic accuracy of Tc-PMT scintigraphy was 94.2%.

Conclusions: Tc-PMT scintigraphy is more accurate in the diagnosis of BA than other conventional examinations. In addition, false positives of Tc-PMT scintigraphy could be reduced by combining γ-GTP level monitoring.