1. From the Departments of Biomedical Engineering (Y.R.), Bioinformatics (X.X.), Radiology (D.L.N., J.Y.L., L.J.G.), and Electrical and Computer Engineering and Biomedical Engineering (J.Y.L.), Duke University, 2424 Erwin Rd, Studio #302, Durham, NC 27705; and iCAD Inc, Nashua, NH (Y.R., Z.L., J. Ge, J. Go).