1. Mallinckrodt Institute of Radiology, Washington University in St. Louis, 510 S Kingshighway Blvd, St. Louis, MO 63110
2. Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN
3. Department of Radiology, The Perelman School of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA
4. Department of Diagnostic Imaging, Rhode Island Hospital, Brown University, Providence, RI
5. Department of Radiology, University of Kentucky, Lexington KY
6. Department of Radiology, Stanford University Medical Center, Stanford University, Stanford, CA