1. Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
2. Radiation Oncology Department, University of Pennsylvania, Philadelphia, PA 19104, USA
3. Ultrasound Research Lab, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19103, USA
4. Informatics Division of the Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
5. Emergency Medicine Department, La Madrida Hospital, 28006 Madrid, Spain