1. Radiation Physics Division; Physical Measurements Laboratory; National Institute of Standards and Technology; Gaithersburg MD 20899 USA
2. Siemens Medical Solutions USA Inc.; Malvern PA 19355 USA
3. Toshiba Medical Research Institute USA Inc.; Vernon Hills IL 60061 USA
4. Department of Radiology; Brigham & Women's Hospital; Boston MA 02115 USA
5. VIDA Diagnostics Inc.; Coralville IA 52241 USA
6. Departments of Radiology and Biomedical Engineering; University of Iowa; Iowa City IA 52242 USA
7. Department of Radiology; National Jewish Health; Denver CO 80206 USA
8. Statistical Engineering Division; Information Technology Laboratory; National Institute of Standards and Technology; Gaithersburg MD 20899 USA
9. Department of Medical Physics; University of Wisconsin School of Medicine and Public Health; Madison WI 53705 USA