1 Department of Emergency Medicine, Keck School of Medicine, University of Southern California, 1200 N. State Street, Room 1011, Los Angeles, California, 90033. Electronic address: Robert.Allen@med.usc.edu.
2 Director of Clinical Ultrasound Fellowship, Department of Emergency Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.
3 Director of Emergency Medicine Ultrasound, Department of Emergency Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.