title: Origin and quantification of differences between normal and tumor tissues observed by terahertz spectroscopy.
abstract: The origin of the differences in the refractive index observed between normal and tumor tissues using terahertz spectroscopy has been described quantitatively. To estimate water content differences in tissues, we prepared fresh and paraffin-embedded samples from rats. An approximately 5% increase of water content in tumor tissues was calculated from terahertz time domain spectroscopy measurements compared to normal tissues. A greater than 15% increase in percentage of cell nuclei per unit area in tumor tissues was observed by hematoxylin and eosin stained samples, which generates a higher refractive index of biological components other than water. Both high water content and high cell density resulted in higher refractive index by approximately 0.05 in tumor tissues. It is predicted that terahertz spectroscopy can also be used to detect brain tumors in human tissue due to the same underlying mechanism as in rats.
authors: R&D Headquarters, Canon Inc., 3-30-2 Shimomaruko, Ohta-ku, Tokyo 146-8501, Japan.
authors: Sayuri
authors: S
authors: Yamaguchi
authors: Yasuko
authors: Y
authors: Fukushi
authors: Oichi
authors: O
authors: Kubota
authors: Takeaki
authors: T
authors: Itsuji
authors: Toshihiko
authors: T
authors: Ouchi
authors: Seiji
authors: S
authors: Yamamoto
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology* / Q000378:metabolism; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology*; D005910:Glioma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012031:Refractometry; D055068:Terahertz Spectroscopy / Q000379:methods*; D014867:Water / Q000737:chemistry* / Q000378:metabolism
chemical_list: D014867:Water