1 From the Imaging Institute, Cleveland Clinic, 9500 Euclid Ave, L10, Cleveland, OH 44195-5243 (D.E.S.); Department of Radiology, University of Alabama at Birmingham School of Medicine, Birmingham, Ala (C.A.W.); Medical Research Institute of New Zealand, Wellington, New Zealand, and Artibiotics, Wellington, New Zealand (C.K.); and Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (K.M.M.).