1. Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
2. Department of Radiology, Seoul National University College of Medicine, Seoul 03080, Korea.
3. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Korea.
4. Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Korea.
5. General Electronics (GE) Healthcare Korea, Seoul 06060, Korea.