Congenital biliary atresia is a rare but dangerous disease. If not treated promptly, it can lead to complications of liver and biliary cirrhosis. Early diagnosis of biliary atresia can help guide treatment, improve clinical symptoms, and reduce the risk of recurrence. Ultrasound is the first-line imaging diagnostic tool because it is safe, non-radioactive, and can be used to monitor progress before and after surgery.

Renal pelvis-ureteral junction stenosis in children is a common urinary tract malformation that obstructs the flow of urine from the renal pelvis to the ureter. If not detected and treated promptly, it can cause dilation of the renal pelvis and serious kidney damage. For children, ultrasound is a safe, non-invasive, non-radioactive diagnostic imaging method and is widely used.