1. From the Department of Radiology (J.R.S., A.P.S., D.W.W., J.H.B., T.G.W., C.P.G.), Department of Pulmonary, Critical Care, Allergy, and Immunologic Medicine (K.W.G.), and Department of Neurology (D.E.S.), Wake Forest School of Medicine, Wake Forest Baptist Health, 1 Medical Center Blvd, Winston-Salem, NC 27157.