 The investigators plan a prospective, multi-center study to determine if liver ultrasound shear wave speed measurements acquired at clinical presentation can discriminate biliary atresia BA from other causes of liver disease in the setting of neonatal cholestasis. The investigators also plan to determine if liver ultrasound shear wave speed measurements acquired at clinical presentation or longitudinally during the first one-year period after Kasai can predict important long-term outcomes in BA patients. 