1. From the Department of Radiology, Enloe Medical Center, 1531 Esplanade, Chico, CA 95926 (H.M.); Department of Radiology, Stanford University School of Medicine, Stanford, Calif (L.M., D.F.); and Department of Radiology, Centre Hospitalier de l’Université de Montréal, Montréal, Quebec, Canada (A.S.C.).