1. From the Departments of Computer Science (J.D., L.M., A.J.B., C.R.) and Electrical and Computer Engineering (C.R.), Duke University, 308 Research Dr, LSRC Building D101, Duke Box 90129, Durham, NC 27708; Department of Radiology and Imaging Services, Emory University, Atlanta, Ga (H.T.); Department of Radiology, Harvard University, Cambridge, Mass (F.S.); and Department of Radiology, Duke University School of Medicine, Durham, NC (J.L.).