1. Department of Biofunctional Imaging Fukushima Medical University Fukushima City Fukushima Japan
2. Drug Discovery and Cyclotron Research Center Southern Tohoku Research Institute for Neuroscience Koriyama Fukushima Japan
3. Department of Radiology National Center of Neurology and Psychiatry Kodaira Tokyo Japan
4. Department of Radiological Sciences School of Health Sciences Fukushima Medical University Sakae Fukushima Japan