1. 1Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2. 2Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3. 3Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, Washington.
4. 4Department of Radiology, University of Washington School of Medicine, Seattle, Washington.
5. 5Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
6. 6Department of Medicine, University of California, San Francisco, San Francisco, California.
7. 7Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California.
8. 8General Internal Medicine Section, Department of Veterans Affairs, University of California, San Francisco, California.
9. 9Department of Public Health Sciences, University of California, Davis, California.
10. 10Department of Surgery and University of Vermont Cancer Center, University of Vermont, Burlington, Vermont.