Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA.|Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA.|Department of Computer Science, University of Southern California, Los Angeles, CA, USA.|Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA.|Department of Computer Science, Stanford University, Stanford, CA, USA.|Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA.|Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA.|Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA.