1. From the Divisions of Thoracic Imaging and Intervention (S.M., F.J.F., M.C.P., J.O.S., A.S.) and Thoracic Surgery (H.C.O., A.M.), Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Founders 2, Boston, MA 02114; and the Department of Radiology, MedStar Georgetown University Hospital, Washington, DC (N.E.F.).