Cancer imaging using terahertz (THz) electromagnetic waves has the potential to overcome the drawbacks of existing cancer imaging techniques because of the unique properties of THz radiation. It is nonionizing, highly sensitive to water molecules, and suitable for the observation of many biomolecular characteristics based on low-energy vibrational modes. Consequently, it is advantageous to use THz cancer imaging for detection, especially of superficial carcinomas in soft tissues. However, there are three primary challenges facing this type of cancer imaging that must be addressed before it can be applied medically: the limited penetration depth in hydrated tissues, the difficulty of obtaining molecular resonance fingerprints of cancers, and the low image contrast between tissues. These challenges can be overcome by applying several state-of-the-art techniques; the penetration depth has been enhanced sufficiently to observe cancer lesions deep inside tissues by using freezing and penetration-enhancing agents: the biochemical modification of DNA can be utilized to track the resonance fingerprints of carcinogenesis at the genomic DNA level; and nanoparticles can increase the THz imaging contrast if they are employed similarly to how they are used in magnetic resonance imaging. These solutions are important to enable THz cancer imaging to be performed in clinical settings.
Joo-Hiuk Son received his BS and MS in electronics engineering from Seoul National University, Seoul, Republic of Korea, in 1986 and 1988, respectively, and his PhD in electrical engineering from the University of Michigan, Ann Arbor, in 1994. His PhD work was on the experimental and theoretical study of transient velocity overshoot dynamics in semiconductors by monitoring femtosecond-laser-driven terahertz pulses. After leaving Michigan, he worked as a postdoctoral scientist at Lawrence Berkeley National Laboratory and the Department of Electrical Engineering and Computer Science, University of California, Berkeley, where he continued his research on the terahertz spectroscopy of semiconductors from 1994 to 1996. In 1997, he joined the Department of Physics at the University of Seoul, Seoul, Republic of Korea, as an assistant professor and was later promoted to professor. In the early years, his research was focused on the characterization of electrical and optical properties of various nanosized materials including carbon nanotubes and graphenes utilizing terahertz time-domain spectroscopy. In recent years, his interest shifted to terahertz electromagnetic interactions with biological materials and their applications in medicine. Combining his expertise on nanomaterials and terahertz medical diagnosis, he invented a highly sensitive terahertz molecular imaging technique using nanoparticle probes. He is an editor of “Terahertz Biomedical Science and Technology” published by CRC Press.