1. From the Department of Radiology, Duke University School of Medicine, 2424 Erwin Road, Suite 302, Durham, NC 27705 (M.B., B.W.T., J.K.H., M.A.M.); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (D.T., W.D.M.); Department of Radiology, University of Alabama at Birmingham, Birmingham, Ala (F.N.T.); and Department of Electrical and Computer Engineering, Duke University, Durham, NC (M.A.M.).