Three-dimensional optical tomography of hemodynamics in the human head

Bluestone, Avraham Y.; Abdoulaev, Gassan S.; Schmitz, Christoph; Barbour, Randall L.; Hielscher, Andreas H.

doi:10.1364/oe.9.000272

Cited by 246 publications

(172 citation statements)

References 46 publications

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“…Here, we refer to the image obtained by an optimal solution of the inverse problem as the diffuse optical tomography (DOT) image. There are only a few published examples of DOT images of brain hemodynamics, for example, in rodents (Culver et al, 2003a,b;Siegel et al, 1999), in newborn human babies (Hintz et al, 2001), and in adult humans (Bluestone et al, 2001). The advancement of true DOT for brain activation in humans would improve the image spatial resolution and quantitative accuracy over that of current interpolating backprojection methods.…”

Section: Improving Image Resolution With Overlapping Measurementsmentioning

confidence: 99%

Diffuse optical imaging of brain activation: approaches to optimizing image sensitivity, resolution, and accuracy

2004

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Near-infrared spectroscopy (NIRS) and diffuse optical imaging (DOI) are finding widespread application in the study of human brain activation, motivating further application-specific development of the technology. NIRS and DOI offer the potential to quantify changes in deoxyhemoglobin (HbR) and total hemoglobin (HbT) concentration, thus enabling distinction of oxygen consumption and blood flow changes during brain activation. While the techniques implemented presently provide important results for cognition and the neurosciences through their relative measures of HbR and HbT concentrations, there is much to be done to improve sensitivity, accuracy, and resolution. In this paper, we review the advances currently being made and issues to consider for improving optical image quality. These include the optimal selection of wavelengths to minimize random and systematic error propagation in the calculation of the hemoglobin concentrations, the filtering of systemic physiological signal clutter to improve sensitivity to the hemodynamic response to brain activation, the implementation of overlapping measurements to improve image spatial resolution and uniformity, and the utilization of spatial prior information from structural and functional MRI to reduce DOI partial volume error and improve image quantitative accuracy. D 2004 Elsevier Inc. All rights reserved.

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Section: Improving Image Resolution With Overlapping Measurementsmentioning

confidence: 99%

Diffuse optical imaging of brain activation: approaches to optimizing image sensitivity, resolution, and accuracy

2004

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“…However, in spite of a significant amount of theoretical work (Boas et al, 2004a,b;Boas and Dale, 2005;Guven et al, 2005;Li et al, 2005;Xu et al, 2005), the literature on practical three dimensional fNIRSI of the human brain is limited to a few papers (Bluestone et al, 2001;Boas et al, 2004b;Hintz et al, 2001;Hoshi et al, 2000;Zhang et al, 2005a,b). The reason for the modest progress in full three-dimensional fNIRS is the combination of the extremely high scattering of light in biological tissue, together with the optical heterogeneity of the human head.…”

Section: Introductionmentioning

confidence: 99%

A spatial and temporal comparison of hemodynamic signals measured using optical and functional magnetic resonance imaging during activation in the human primary visual cortex

2007

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Functional near infrared spectro-imaging (fNIRSI) is potentially a very useful technique for obtaining information about the underlying physiology of the blood oxygenation level dependent (BOLD) signal used in functional magnetic resonance imaging (fMRI). In this paper the temporal and spatial statistical characteristics of fNIRSI data are compared to those of simultaneously acquired fMRI data in the human visual cortex during a variable-frequency reversing checkerboard activation paradigm. Changes in the size of activated volume caused by changes in checkerboard reversal frequency allowed a comparison of the behavior of the spatial responses measured by the two imaging methods. fNIRSI and fMRI data were each analyzed using standard correlation and fixed-effect group analyses of variance pathways. The statistical significance of fNIRSI data was found to be much lower than that of the fMRI data, due mainly to the low signal-to-noise of the measurements. Reconstructed images also showed that, while the time-course of changes in the oxy-, deoxy-, and total hemoglobin concentrations all exhibit high correlation with that of the BOLD response, the changes in the volume of tissue measured as "activated" by the BOLD response demonstrate a closer similarity to the corresponding changes in the oxy-and total hemoglobin concentrations than to that of the deoxyhemoglobin.

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“…Reconstructions of hemodynamic changes in the adult head based on intensity data have been reported in (Bluestone et al, 2001). The authors repeatably performed the Valsava maneuver on the subject, and reconstructed a time-series of images representing the changes in the concentrations of oxy-and deoxyhemoglobin in a volume under the forehead of the subject.…”

Section: Optical Tomography Of the Brainmentioning

confidence: 99%

Diffuse Optical Imaging

Nissilä

Noponen

Heino

et al.

Advances in Electromagnetic Fields in Living Systems

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Diffuse optical imaging is a functional medical imaging modality which takes advantage of the relatively low attenuation of near-infrared light to probe the internal optical properties of tissue. The optical properties are affected by parameters related to physiology such as the concentrations of oxy-and deoxyhemoglobin. Instrumentation that is used for optical imaging is generally able to measure changes in the attenuation of light at several wavelengths, and in the case of time-and frequency-domain instrumentation, the time-of-flight of the photons in tissue.Light propagation in tissue is generally dominated by scattering. Models for photon transport in tissue are generally based on either stochastic approaches or approximations derived from the radiative transfer equation. If a numerical forward model which describes the physical situation with sufficient accuracy exists, inversion methods may be used to determine the internal optical properties based on boundary measurements.Optical imaging has applications in, e.g., functional brain imaging, breast cancer detection, and muscle imaging. It has the important advantages of transportable instrumentation, relatively high tolerance for external electromagnetic interference, non-invasiveness, and applicability for neonatal studies. The methods are not yet in clinical use, and further research is needed to improve the reliability of the experimental techniques, and the accuracy of the models used. In this chapter, we describe the interaction between light and tissue, light propagation models and inversion methods used in optical tomography, and instrumentation and experimental techniques used in optical imaging. The main applications of optical imaging are described in detail, with results from recent literature.

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Three-dimensional optical tomography of hemodynamics in the human head

Cited by 246 publications

References 46 publications

Diffuse optical imaging of brain activation: approaches to optimizing image sensitivity, resolution, and accuracy

Diffuse optical imaging of brain activation: approaches to optimizing image sensitivity, resolution, and accuracy

A spatial and temporal comparison of hemodynamic signals measured using optical and functional magnetic resonance imaging during activation in the human primary visual cortex

Diffuse Optical Imaging

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