1. Center for Evidence-Based Imaging, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115.
2. Department of Radiology, Brigham and Women's Hospital, Boston, MA.
3. Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA.
4. Harvard Medical School, Boston, MA.
5. Department of Medicine, Brigham and Women's Hospital, Boston, MA.
6. Department of Emergency Medicine, Brigham and Women's Hospital, Boston, MA.
7. Department of Urology, Brigham and Women's Hospital, Boston, MA.