1. From the Departments of Medicine (I.B., E.A.S., J.M.R.-L.), Radiology (W.R.B.), Anesthesia (J.C.C.), and Pathology (B.H.), Massachusetts General Hospital, and the Departments of Medicine (I.B., E.A.S., J.M.R.-L.), Radiology (W.R.B.), Anesthesia (J.C.C.), and Pathology (B.H.), Harvard Medical School — both in Boston.