1. Comprehensive Kidney Stone Center, Duke University Medical Center, Durham, North Carolina.
2. Radiation Safety Division, Duke University Medical Center, Durham, North Carolina.
3. Department of Radiology, Duke University, Durham, North Carolina.
4. Graduate Program of Medical Physics, Duke University, Durham, North Carolina.
5. Urology Department, University of California, Irvine, Orange, California.
6. Duke Clinical Research Institute, Duke University, Durham, North Carolina.
7. Department of Radiation Oncology, Duke University, Durham, North Carolina.