1. From the Department of Radiology, University of Kentucky, 800 Rose St, MN 109-B, Lexington, KY 40536 (A.R.A., J.T.L.); Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Ga (K.H., J.L., G.J., J.G., C.H., T.N.H.); and Department of Radiology, Boston University, Boston, Mass (C.A.L., A.J., J.A.S.).