1. Department of Emergency Medicine, University of California, San Francisco, 505 Parnassus Ave, San Francisco, CA 94143
2. Department of Emergency Medicine and Pediatrics, University of California, San Francisco, San Francisco, CA
3. Departments of Radiology and Biomedical Imaging, Epidemiology and Biostatistics and the Philip R. Lee Institute for Health Policy Studies, University of California San Francisco, San Francisco, CA
4. Department of Surgery, McGovern Medical School at UTHealth, Houston, TX