Time-Resolved Diffuse Optical Tomography of Human Forearm Under Exercise

Light in the near-infrared wavelength range can penetrate deeping into biological tissues because the absorption by both water and hemoglobin is much smaller than in the other wavelength ranges. Oxygenated and deoxygenated hemoglobins have different light absorption characteristics. Therefore, by obtaining tomographic images of the absorption characteristics, it will be possible to know the hemodynamics inside deep tissues. Thus, the diffuse optical tomography (DOT) is expected as a new modality of biomedical imaging. In this study, we try to obtain DOT images of the forearms by conducting two types of exercise, and their differences caused by the muscle activity are discussed. By comparing the reconstructed DOT images with the magnetic resonance images of the forearm at the same position, the activated muscles can be identified in detail. As a result, the hemodynamics in the dominant muscles when performing flexion and extension of wrist are observed.

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Effect of the Arrangement of Optodes for 3D Diffuse Optical Tomography

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44480 ◽

2011 ◽

Author(s):

Kazuhiro Uchida ◽

Shinpei Okawa ◽

Kazuto Masamoto ◽

Yoko Hoshi ◽

Yukio Yamada

Keyword(s):

Blood Volume ◽

Wavelength Range ◽

Near Infrared ◽

Optical Tomography ◽

Diffuse Optical Tomography ◽

High Quality ◽

Tomographic Images ◽

Infrared Wavelength ◽

Optimum Arrangement ◽

Simulation Results

Diffuse optical tomography (DOT) can obtain tomographic images of hemodynamics such as the oxygenation state and blood volume in tissues using light in the near infrared wavelength range where tissues absorb light weakly and oxy- and deoxy-hemoglobins show different absorbing characteristics. For 3D-DOT, much more optodes than those for 2D-DOT are desirable for high quality images. But practically the number of the optodes is limited and it is necessary to find the optimum arrangement of the optodes. This paper studies the effect of the optode arrangement on the reconstructed images by simulation of 3D-DOT when the number of the optodes is 16 and the object is a sphere with a diameter of 100 mm. Simulation results show that the optode arrangement which can effectively detect the light propagating through the target is important to reconstruct the target at the correct positions.

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Influences of target size and contrast on near infrared diffuse optical tomography: a comparison between featured-data and full time-resolved schemes

10.1117/12.710877 ◽

2006 ◽

Author(s):

Feng Gao ◽

Huijuan Zhao ◽

Yukari Tanikawa ◽

Kazuhiro Homma ◽

Yukio Yamada

Keyword(s):

Near Infrared ◽

Optical Tomography ◽

Diffuse Optical Tomography ◽

Target Size ◽

Full Time ◽

Time Resolved

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Near-Infrared Diffuse Optical Tomography

Disease Markers ◽

10.1155/2002/164252 ◽

2002 ◽

Vol 18 (5-6) ◽

pp. 313-337 ◽

Cited By ~ 94

Author(s):

A. H. Hielscher ◽

A. Y. Bluestone ◽

G. S. Abdoulaev ◽

A. D. Klose ◽

J. Lasker ◽

...

Keyword(s):

Near Infrared ◽

Imaging Modality ◽

Low Cost ◽

Optical Tomography ◽

Diffuse Optical Tomography ◽

Biological Tissues ◽

Body Parts ◽

Reconstruction Algorithms ◽

Cross Sectional ◽

Magnetic Resonance Imaging Mri

Diffuse optical tomography (DOT) is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR) light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI) or X-ray computerized tomography (CT), DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals.

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