1. Section of Nuclear Medicine, Department of Radiology, Duke University Medical Center
2. Department of Biomedical Engineering, Duke University, Durham, North Carolina 27710
3. Photon Imaging, Inc., 19355 Business Center Drive, Suite 8, Northridge, California 91324
4. Division of Nuclear Medicine & Biophysics, Department of Molecular & Medical Pharmacology, UCLA School of Medicine, Los Angeles, California 90095