Increased Liver Stiffness: A Study of Acoustic Radiation Force Impulse (ARFI) Elastography

The goal of this study is to determine if ultrasound tools can be used to detect liver stiffness. Acoustic radiation force impulse (ARFI) elastography and backscatter will be used to see if they can detect liver stiffness in different populations of patients with liver disease. The study is measuring liver stiffness in pediatric patients aged 2-5 years. Patients either have had a Fontan cardiac surgery or have liver disease. Ultrasound scanning takes images of the liver and has much lower risks for patients. ARFI elastography and other tools can be used to measure liver stiffness.