Shear Wave Elastography: A Reliable Secondary Parameter for Diagnosing Biliary Atresia in Infants With Neonatal Cholestasis

Objective In this study, we aimed to optimize various grayscale, Doppler, and elastography parameters and evaluate their diagnostic performance in the preoperative diagnosis of biliary atresia (BA). Materials and methods A total of 158 infants aged <6 months with neonatal cholestasis (NC) were enrolled in the study and sonography was performed after four hours of fasting. For comparison of elastography, 31 exclusively age-matched controls, not suffering from liver disease, were included separately. Triangular cord and gallbladder (GB) parameters were considered as primary parameters, while right hepatic artery (RHA) caliber, RHA-to-right portal vein (RPV) ratio, hepatic subcapsular flow (HSF), and shear wave elastography (SWE) were considered as secondary parameters. Diagnosis of infants with BA was confirmed on histopathology. Data were presented as mean ±standard deviation (SD) and frequency. Differences between groups were compared using the Chi-square test and the unpaired student t-test. Receiver operating characteristic (ROC) curve analysis was done for individual ultrasound/Doppler/SWE parameters to calculate the optimal cutoff value. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for each parameter and their combinations. Results Of the primary parameters, GB contractility index (CI) and length showed the highest sensitivity and specificity respectively. A cutoff of 14 kPA was derived for SWE for the diagnosis of BA. Among secondary parameters, SWE had the best diagnostic performance, better than even the individual primary parameters. A combination of primary parameters with SWE in series showed the highest accuracy. Conclusion Among secondary parameters, elastography can prove to be highly useful. The highest accuracy in diagnosing BA can be obtained by combining primary parameters with SWE.