1. From the Departments of Radiology (D.B.L., M.P.L., S.S.H., C.P.L.), Computer Science (M.C.C.), and Biomedical Informatics (C.P.L.), Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105; and Department of Radiology, Children’s Hospital Colorado, Aurora, Colo (N.V.S.).