1. From the Department of Radiology (J.A.M., Z.Z., B.K., M.A.M., W.F.W., M.R.B.), Department of Electrical and Computer Engineering (M.A.M.), Department of Computer Science (M.A.M.), Center for Advanced Magnetic Resonance Development (M.R.B.), and Division of Gastroenterology, Department of Medicine (M.R.B.), Duke University, 2301 Erwin Rd, Durham, NC 27710.