1. From the Department of Radiology (Thoracic Division), Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115 (M.M.H.); Institute of Technology Assessment, Massachusetts General Hospital, Boston, Mass (A.L.E.); Department of Statistical Science, Duke University, Durham, NC (L.L.P.); and Icahn School of Medicine at Mount Sinai, New York, NY (C.Y.K.).