1. From the Department of Radiology, Maisonneuve-Rosemont Hospital, Université de Montréal, 5415 Assumption Blvd, Montreal, QC, Canada H1T 2M4 (G.F.); Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Mass (A.O., S.I.L.); and Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass (G.M.N.).