1. Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, 2301 Erwin Rd, Durham, NC 27705.
2. Department of Radiology, Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC.
3. Department of Radiology, Duke University, Durham, NC.
4. Department of Radiology, Division of Pediatric Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, NC.