1. From the Department of Medicine, Boston Medical Center (H.W.F.), the Department of Medicine, Boston University School of Medicine (H.W.F.), the Departments of Radiology (S.M.), Medicine (A.S.W., N.P.K., E.M.M.), and Pathology (J.R.S.), Massachusetts General Hospital, and the Departments of Radiology (S.M.), Medicine (A.S.W., N.P.K., E.M.M.), and Pathology (J.R.S.), Harvard Medical School — all in Boston.