1. From the Department of Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (L.F.A., J.D.L., J.G.C.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (T.N.H., P.A.H.); Department of Radiology, University of Mississippi Medical Center, Jackson, Miss (M.S.R.); and Department of Radiology and Imaging, Medical College of Georgia, Augusta, Ga (P.K.M.).