1. From the Department of Radiology, The Ottawa Hospital, University of Ottawa, 1053 Carling Ave, Ottawa, ON, Canada K1Y4E9 (M.L.B.V.); Division of Diagnostic Imaging, Sheba Medical Center, Tel Aviv, Israel (M.K.); Department of Radiology, University of California San Diego, San Diego, Calif (M.H.); and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Mass (C.V.).