1. Department of Radiology, Stanford University School of Medicine, Stanford, CA.
2. Department of Radiology, Division of Abdominal Imaging, Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.
3. Carl E. Ravin Advanced Imaging Laboratories (RAI Laboratories), Duke University Medical Center, Durham, NC.
4. Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC.