1 From the Department of Radiology and Imaging Sciences (G.J., S.N.G., K.D.H.) and Department of Emergency Medicine (G.J., K.D.H.), Emory University School of Medicine, 550 Peachtree Street NE, Atlanta, GA, 30308; Department of Radiology and Imaging Sciences, Grady Medical Hospital, Atlanta, Ga (G.J., K.D.H.); DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, Tenn (D.A.S.); and Mallinckrodt Institute of Radiology (V.M.M., C.J.) and Department of Pediatrics, Saint Louis Children's Hospital (C.J.), Washington University School of Medicine, St Louis, Mo.