1. From the Department of Medicine, University of Alabama Birmingham School of Medicine, Birmingham (M.S.); and the Departments of Radiology (D.P.M.), Medicine (M.S.S., G.M.C.), and Pathology (A.R.S.), Massachusetts General Hospital, and the Departments of Radiology (D.P.M.), Medicine (M.S.S., G.M.C.), and Pathology (A.R.S.), Harvard Medical School — both in Boston.