Functional imaging of the vascular bed by dynamic optical tomography

Barbour, Randall L.; Graber, Harry L.; Pei, Yaling; Schmitz, Christoph; Xu, Yong; Martino, Adriana Di; Castellanos, F. Xavier; Klemer, David P.; Hardin, Rosemarie E.; Franco, Nelson A.; Katz, Michael; Zenilman, Michael E.; Smeraldi, Alessandro G.; Panetta, Thomas F.

doi:10.1117/12.537957

Cited by 7 publications

(9 citation statements)

References 24 publications

(27 reference statements)

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“…Second, we have sought to improve on the stability and speed of the numerical methods used for image reconstruction [29]- [31]. Third, we have focused our attention on characterizing the accuracy with which temporal information attributable to dynamic processes can be identified in reconstructed spatial maps obtained using the experimental and numerical methods we have developed [2]- [4].…”

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confidence: 99%

Imaging of spatiotemporal coincident states by DC optical tomography

Graber

Pei²,

Barbour

2002

IEEE Trans. Med. Imaging

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Abstract-The utility of optical tomography as a practical imaging modality has, thus far, been limited by its intrinsically low spatial resolution and quantitative accuracy. Recently, we have argued that a broad range of physiological phenomena might be accurately studied by adopting this technology to investigate dynamic states ( One such phenomenon holding considerable significance is the dynamics of the vasculature, which has been well characterized as being both spatially and temporally heterogeneous.In this paper, we have modeled such heterogeneity in the limiting case of spatiotemporal coincident behavior involving optical contrast features, in an effort to define the expected limits with which dynamic states can be characterized using two newly described reconstruction methods that evaluate normalized detector data: the normalized difference method (NDM) and the normalized constraint method (NCM). Influencing the design of these studies is the expectation that spatially coincident temporal variations in both the absorption and scattering properties of tissue can occur in vivo. We have also chosen to model dc illumination techniques, in recognition of their favorable performance and cost for practical systems. This choice was made with full knowledge of theoretical findings arguing that separation of the optical absorption and scattering coefficients under these conditions is not possible.Results obtained show that the NDM algorithm provides for good spatial resolution and excellent characterization of the temporal behavior of optical properties but is subject to interparameter crosstalk. The NCM algorithm, while also providing excellent characterization of temporal behavior, provides for improved spatial resolution, as well as for improved separation of absorption and scattering coefficients. A discussion is provided to reconcile these findings with theoretical expectations.Index Terms-Crosstalk and nonuniqueness, dynamic optical tomography, inverse problem, physiological dynamics, physiological oscillations.

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confidence: 99%

Imaging of spatiotemporal coincident states by DC optical tomography

Graber

Pei²,

Barbour

2002

IEEE Trans. Med. Imaging

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“…By contrast, while we also adopt applied-force maneuvers as a means to provoke a physiological response, we believe it is important to specifically measure the mechanical response as well as to impose maneuvers in ways that support a broad range of protocols. Beyond this, and in keeping with our original description of the fundamental utility of dynamic NIR spectroscopic tomography [16,17], we believe that the capacity to account for intrinsic responses by involving simultaneous bilateral breast measures should serve to improve the diagnostic potential of any given protocol.…”

Section: Inversion Of Optical Datamentioning

confidence: 99%

“…Among the features that have been described using this approach are elements of the hemoglobin (Hb) signal, tissue water, lipid, and measures of scattering amplitude and scattering power [15]. The other approach is to define dynamic responses of the tissue based on measures of relative changes in the optical signal [16,17]. While not easily supporting absolute constituent measures, this approach has the added benefit of exploring any of a host of dynamic features associated with Hb signals that may occur spontaneously (e.g., vascular rhythms) [18] or can be induced by controlled provocations [19,20].…”

Section: Introductionmentioning

confidence: 99%

Optomechanical imaging system for breast cancer detection

Abdi

Graber

et al. 2011

J. Opt. Soc. Am. A

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Imaging studies of the breast comprise three principal sensing domains: structural, mechanical, and functional. Combinations of these domains can yield either additive or wholly new information, depending on whether one domain interacts with the other. In this report, we describe a new approach to breast imaging based on the interaction between controlled applied mechanical force and tissue hemodynamics. Presented is a description of the system design, performance characteristics, and representative clinical findings for a second-generation dynamic near-infrared optical tomographic breast imager that examines both breasts simultaneously, under conditions of rest and controlled mechanical provocation. The expected capabilities and limitations of the developed system are described in relation to the various sensing domains for breast imaging.

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“…An important point, stressed in our first dynamic-imaging report [1] and has elaborated upon in subsequent papers and presentations [5][6][7], is that the most effective means of extracting clinically valuable information available from NIR optical tomography is through application of mathematical time-series analysis methods to sequences of detector data and/or reconstructed images rather than by direct inspection of individual optical coefficient or hemoglobin concentration images. This point is born out by the case results to follow, wherein a different analytic strategy we are studying was used to analyze the data collected from each subject.…”

Section: Introductionmentioning

confidence: 99%

Time-frequency analysis of functional optical mammographic images

et al. 2003

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We have introduced working technology that provides for time-series imaging of the hemoglobin signal in large tissue structures. In this study we have explored our ability to detect aberrant time-frequency responses of breast vasculature in subjects with Stage II breast cancer, at rest and in response to simple provocations. The hypothesis being explored is that time-series imaging will be sensitive to the known structural and functional malformations of the tumor vasculature. Mammographic studies were conducted using an adjustable hemispheric measuring head containing 21 source and 21 detector locations (for 441 source-detector channels). Simultaneous dual-wavelength (760 and 830 nm) studies were performed on women lying prone with the breast hanging in a pendant position. Two classes of measure were performed: 1) 20-minute baseline measurements wherein the subject was at rest; 2) provocation studies wherein the subject was asked to perform some simple breathing maneuvers. Collected data were analyzed to identify the central tendencies and time-frequency structure of the detector responses, and those of the image time series. Image data were generated using the Normalized Difference Method [Pei et al., Appl. Opt. 40, 5755-5769 (2001)]. Results obtained clearly document three classes of dynamic anomaly in the tumor-bearing breast relative to the healthy contralateral breast. First, breast tumors exhibit oxygen supply/demand imbalance in response to an oxidative challenge (breath hold). Second, the vasomotor response of the tumor vasculature is mainly depressed and exhibits an altered modulation. Third, the region of the breast wherein the altered vasomotor signature is seen extends well beyond the margins of the tumor itself.

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Functional imaging of the vascular bed by dynamic optical tomography

Cited by 7 publications

References 24 publications

Imaging of spatiotemporal coincident states by DC optical tomography

Imaging of spatiotemporal coincident states by DC optical tomography

Optomechanical imaging system for breast cancer detection

Time-frequency analysis of functional optical mammographic images

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