1 May 1991 Near-infrared imaging in vivo: imaging of Hb oxygenation in living tissues
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Proceedings Volume 1431, Time-Resolved Spectroscopy and Imaging of Tissues; (1991) https://doi.org/10.1117/12.44203
Event: Optics, Electro-Optics, and Laser Applications in Science and Engineering, 1991, Los Angeles, CA, United States
Abstract
1 ) To enhance spatial resolution of near-infrared (NIR) imaging in vivo, we performed computer-aided refocusing of NIR-projection images of human forearm. Simple inverse, constrained least squares, and Wiener filters were tested as refocusing algorithms. Wiener filter gave the best result in terms of image quality and computation time. By applying Wiener filter, we obtained enhanced spatial resolution. 2) We also examined 2-dimensional visualization of Hb oxygenation state using NIR-projection images of human forearm. Forearm occlusion caused increase in 2-dimensional O.D. at 700 nm, while slight decrease was observed at 800 nm. On the basis of in vitro experiments using RBC suspension and test phantoms, we calculated 2-dimensional changes in Hb oxygenation in the human forearm caused by ischemia. 3) To confirm whether NIR-CT can detect changes in Hb quantity in the living tissues, we reconstructed CT images from NIR-projection data of mouse abdomen measured at 700 and 800 nm. Infusion of physiological saline into the liver caused decrease in gray level in the location of the liver in the CT images (700-800 nm), although uncertain artifacts were observed in the other areas. Although more detailed considerations are required for practical application of this technique, we have obtained NIR-projection and CT images which indicate regional changes in the state of Hb in the living tissues.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ryuichiro Araki, Ryuichiro Araki, Ichiro Nashimoto, Ichiro Nashimoto, } "Near-infrared imaging in vivo: imaging of Hb oxygenation in living tissues", Proc. SPIE 1431, Time-Resolved Spectroscopy and Imaging of Tissues, (1 May 1991); doi: 10.1117/12.44203; https://doi.org/10.1117/12.44203
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