1. From the Departments of Medicine (M.W.F., S.L.A., R.H.G.), Radiology (A.K.S.), Neurology (A.C.G.), and Pathology (N.F.C.), Massachusetts General Hospital, and the Departments of Medicine (M.W.F., S.L.A., R.H.G.), Radiology (A.K.S.), Neurology (A.C.G.), and Pathology (N.F.C.), Harvard Medical School — both in Boston.