1. From the Department of Medicine, Hospital of the University of Pennsylvania, and the Perelman School of Medicine, University of Pennsylvania — both in Philadelphia (J.S.B.); and the Departments of Radiology (O.R.), Medicine (A.Z.F., J.B.E.K.), and Pathology (V.E.K., M.N.A.), Massachusetts General Hospital, and the Departments of Radiology (O.R.), Medicine (A.Z.F., J.B.E.K.), and Pathology (V.E.K., M.N.A.), Harvard Medical School — both in Boston.