1. From the Departments of Emergency Medicine, (K.W., M.S., C.M.) and Radiology and Biomedical Imaging (A.M.), Yale School of Medicine, 464 Congress Ave, Suite 273, New Haven, CT 06510; Department of Quality and Safety, American College of Radiology, Reston, Va (P.K., D.S., M.B.C., J.B.); and Department of Radiology, Massachusetts General Hospital, Boston, Mass (M.K.).