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

Hepatobiliary scintigraphy plays an important role in the differentiation of biliary atresia (BA) and non-BA. The usefulness of ^99mTc-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 ^99mTc-N-pyridoxyl-5-methyl-tryptophan (PMT). Our objective was to evaluate the usefulness of ^99mTc-PMT scintigraphy in the diagnosis of BA.

52 infants who received ^99mTc-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 ^99mTc-PMT scintigraphy, various clinical and investigational parameters in the diagnosis of BA.

The final diagnoses in this group were BA (67.3%) and non-BA (32.7%). ^99mTc-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 ^99mTc-PMT scintigraphy and γ-GTP were independent predictors of BA. The diagnostic accuracy of ^99mTc-PMT scintigraphy was 94.2%.

^99mTc-PMT scintigraphy is more accurate in the diagnosis of BA than other conventional examinations. In addition, false positives of ^99mTc-PMT scintigraphy could be reduced by combining γ-GTP level monitoring.