1. From the Department of Radiology, Saint Louis University Hospital, 3635 Vista Ave, 2nd Floor, Deslodge Tower, St Louis, MO 63103-2097 (J.M., A.U.); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (J.M., M.Z.); Department of Radiology, Mayo Clinic, Scottsdale, Ariz (K.S.Z., C.O.M.); and Department of Radiology, Massachusetts General Hospital, Boston, Mass (A.H.).