1. Department of Emergency Medicine, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA (A.M.C., J.EH.).
2. Department of Radiology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia (H.I.L.).
3. Center for Statistical Sciences (B.S.S., C.G.)
4. Department of Biostatistics (C.G.)
5. Brown University School of Public Health, Providence, RI. Novartis Institutes for BioMedical Research, Cambridge, MA (E.M.G.).
6. Department of Emergency Medicine, Wake Forest School of Medicine, Winston-Salem, NC (C.D.M.).
7. Department of Radiology, Pennsylvania State Hershey Medical Center (H.S.).
8. Johns Hopkins School of Medicine, Baltimore, MD (K.J.O.).