Takahito Nakajima, MD, Ph.D. is a radiologist with a career of over 20 years. He works at Gunma University Hospital and is the vice chair of the Radiology Department. His interest is in diagnostic radiology, including CT, MRI, PET, nuclear medicine and ultrasound sonography, ranging from basic science to clinical studies. In basic research, he engaged in in-vivo fluorescence imaging, in particular, activatable fluorescence and near-infrared based photoimmunotherapy. He has a long history of working in the clinical field and contributes quantitative imaging in various organs, with contrast agents being one of his research fields.