1 Center for Evidence-Based Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Department of Emergency Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.
2 Center for Evidence-Based Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.
3 Center for Evidence-Based Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.