1 Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1364 Clifton Rd, Room 125 D, Atlanta, GA 30322. Electronic address: gsadigh@emory.edu.
2 Harvey L. Neiman Health Policy Institute, Reston, Virginia; School of Economics, Georgia Institute of Technology, Atlanta, Georgia.
3 Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.