1. Kavli IPMU, The University of Tokyo, Kashiwa, Japan
2. Department of Physics, The University of Tokyo, Tokyo, Japan
3. Occupational Health and Safety Section, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
4. High Energy Accelerator Research Organization, Tsukuba, Japan
5. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan
6. Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
7. Division of Functional Imaging, National Cancer Center, Kashiwa, Japan
8. Department of Medical Imaging and College of Optical Sciences, University of Arizona, Tucson, AZ, USA