title: Near-infrared laser tomographic imaging with right-angled scattered coherent light using an optical heterodyne-detection-based confocal scanning system.
abstract: We demonstrate, what is to the best of our knowledge, a novel optical tomographic method for the visualization of the inner structure of scattering media such as biological tissue in the near-infrared region. We constructed a scanning confocal imaging system with a cross-axes arrangement using optical fibers. This system is based on the optical heterodyne technique and enables the detection of very weak coherence photons that are generated in the spatially restricted confocal region and scattered laterally (90 degrees ) against an incident beam. To evaluate the fundamental imaging capabilities of the system, we assessed measurements from scattering phantoms composed of an Intralipid suspension with varying volume concentrations. The results of this study demonstrate that the right-angled scattered light adheres to the Lambert-Beer law and that the present system can detect light propagating through a distance of approximately 31l of the mean free path. An inclusion as small as 100 microm can be discriminated in a scattering media with an optical thickness of 4. We investigated the potential of the proposed system for imaging biological tissues in preliminary experiments using samples of chicken breast tissue.
authors: Department of Bio-System Engineering, Yamagata University, Yonezawa, Japan. inishi@yz.yamagata-u.ac.jp
authors: Izumi
authors: I
authors: Nishidate
authors: Masaki
authors: M
authors: Goto
authors: Yoshiaki
authors: Y
authors: Sasaki
authors: Tetsuya
authors: T
authors: Yuasa
authors: Balasigamani
authors: B
authors: Devaraj
authors: Kyuichi
authors: K
authors: Niizeki
authors: Takao
authors: T
authors: Akatsuka
mesh_terms: D000818:Animals; D001940:Breast / Q000166:cytology; D002645:Chickens; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000295:instrumentation* / Q000379:methods; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods