1. From the Department of Radiology, VA Palo Alto Health Care System, Palo Alto, Calif (S.T.C.); Department of Radiology, Stanford University School of Medicine, 300 Pasteur Dr, H1307 MC 5621, Stanford, CA 94305 (S.T.C., T.S.D.); Department of Radiology, Mayo Clinic, Scottsdale, Ariz (C.O.M., A.K.H.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (M.G.L.); and Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (V...