Imaging in Transport Processes

ISBN Print: 978-1-56700-382-6

NEAR-INFRARED IMAGING IN VIVO

Sinopsis

Oxygenation-deoxygenation state of hemoglobin (Hb) in vivo has been measured here by means of near-infrared (NIR) spectrophotometry. Several authors have examined quantitative analysis of Hb oxygenation in the living tissues on the basis of 2- or 3-wavelength spectrophotometry and multicomponent analysis of NIR spectra. However, attempts to measure spatial distribution of this parameter by NIR spectrophotometry, namely, NIR imaging, have been hampered by strong light scattering due to optical turbidity of the tissues, and thus have not been established yet. Since NIR imaging in vivo has potential capability to measure spatial distribution of tissue oxygen insufficiency noninvasively, picosecond time-resolved spectroscopy and coherent detection imaging have been proposed to reduce scattered light components. However, the intensity of the unscattered component in the light transmitted through the tissue is weak and it is difficult to obtain a sufficient quality of images. To utilize scattered light components, we applied computer-aided image refocusing technique, and obtained improved resolution of the NIR imaging. By using 2-wavelength imaging technique, we have also obtained NIR-projection and CT images which indicate the state of Hb in living tissues.