X-ray, MRI and ultrasound have problems of ionized radiation, large-scale equipment and limited spatial resolution, respectively. The near-infrared (NIR) light can be the candidate of another modality for medical imaging. Its attenuation in animal tissue is relatively low among light wavelengths, and we can detect the NIR light through an animal body. However, because of the strong scattering in the tissue, it is difficult to get clear image of deep-seated structure in the tissue. Its practical applicability has been limited only to the subcutaneous structure in thin body parts. We have developed some techniques to suppress the scattering in turbid media, and attempted to use them for the imaging through animal body. The NIR imaging is radiation-free and can be implemented into a small and light instrument. This talk presents the techniques for three dimensional (3D) trans-body imaging, and the examples of their application to noninvasive imaging of macroscopic internal structure.

Koichi Shimizu received M.S. and Ph.D. degrees, from University of Washington (UW), Seattle, USA in 1976 and 1979, respectively. He was a Research Associate in University of Washington in 1974-79. He was an Assistant Professor, an Associate Professor, and a Professor in Hokkaido University, Sapporo, Japan in 1979-2016. He was a Professor in Waseda University in 2016-2021. He is currently a Professor of Xidian University, China, an Invited Research Professor of Waseda University, Japan, and a Professor Emeritus of Hokkaido University, Japan. He has been engaged in the studies of biomedical engineering including those of wave propagation in biological media, optical imaging and measurement, biotelemetry, and biological effects of electromagnetic field. He served as an associate editor of IEEE Trans. ITB in 1999–2007. He has been a Fellow of the Electromagnetics Academy, and an editorial board member of Scientific Reports, Nature.