1. Department of Radiology Technology, Faculty of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
2. Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
3. Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
4. Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
5. Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva 4, Switzerland
6. Geneva University Neurocenter, Geneva University, Geneva, Switzerland
7. Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
8. Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark