1. From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114 (P.N.); Department of Radiology, New York University School of Medicine, New York, NY (B.B., H.C.); and Biomedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY (L.F.).