Prospective Assessment of Ultrasound Shear Wave Elastography for Discriminating Biliary Atresia from other Causes of Neonatal Cholestasis

Abstract

To prospectively assess the diagnostic performance of ultrasound shear wave elastography (SWE) and hepatobiliary laboratory biomarkers for discriminating biliary atresia from other causes of neonatal cholestasis. Forty-one patients <3months of age with neonatal cholestasis (direct bilirubin >2mg/dL) and possible biliary atresia were prospectively enrolled. Both 2-dimensional (2D) and point ultrasound SWE were performed prior to knowing the final diagnosis. Median 2D (8) and point (10) shear wave speed measurements were calculated for each subject and used for analyses. The Mann-Whitney U test was used to compare shear wave speed and laboratory measurements between patients with and without biliary atresia. Receiver operating characteristic curve analyses and multivariable logistic regression were used to evaluate diagnostic performance. Thirteen subjects (31.7%) were diagnosed with biliary atresia, and 28 subjects (68.3%) were diagnosed with other causes of neonatal cholestasis. Median age at the time of ultrasound SWE was 37days. Median 2D (2.08 vs 1.49m/s, P=.0001) and point (1.95 vs 1.21m/s, P=.0014) ultrasound SWE measurements were significantly different between subjects with and without biliary atresia. Using a cut-off value of >1.84m/s, 2D ultrasound SWE had a sensitivity=92.3%, specificity=78.6%, and area under the receiver operating characteristic curve (AuROC) of 0.89 (P<.0001). Using a cut-off value of >320 (U/L), gamma-glutamyl transferase (GGT) had a sensitivity=100.0%, specificity=77.8%, and AuROC of 0.85 (P<.0001). Multivariable logistic regression demonstrated an AuROC of 0.93 (P<.0001), with 2 significant covariates (2D ultrasound SWE [OR=23.06, P=.01]; GGT [OR=1.003, P=.036]). Ultrasound SWE and GGT can help discriminate biliary atresia from other causes of neonatal cholestasis.