WO2005083396A1 - Imagerie optique a onde continue tenant compte d'une loi de dispersion - Google Patents

Imagerie optique a onde continue tenant compte d'une loi de dispersion Download PDF

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Publication number
WO2005083396A1
WO2005083396A1 PCT/CA2004/000297 CA2004000297W WO2005083396A1 WO 2005083396 A1 WO2005083396 A1 WO 2005083396A1 CA 2004000297 W CA2004000297 W CA 2004000297W WO 2005083396 A1 WO2005083396 A1 WO 2005083396A1
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WIPO (PCT)
Prior art keywords
scatter
optical
concentration
chromophores
tissue
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Application number
PCT/CA2004/000297
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English (en)
Inventor
David J. Hall
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Art Advanced Research Technologies Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Art Advanced Research Technologies Inc. filed Critical Art Advanced Research Technologies Inc.
Priority to PCT/CA2004/000297 priority Critical patent/WO2005083396A1/fr
Publication of WO2005083396A1 publication Critical patent/WO2005083396A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/4795—Scattering, i.e. diffuse reflection spatially resolved investigating of object in scattering medium
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters

Definitions

  • TECHNICAL FIELD This invention relates to the field of optical imaging. More specifically the invention relates to the field of optical imaging of homogeneous or inhomogeneous turbid media such as biological tissue using continuous wave (CW) measurements.
  • CW continuous wave
  • TPSF based approaches are well suited for extracting absorption coefficients but the approach relies on expensive and complex hardware and software in order to perform the TPSF-based measurements. It is recognized that CW techniques are less expensive and simpler than the TPSF-based approach. However, it is well-known that the CW approach can only measure the attenuation coefficient and cannot decouple this into the absorption and scattering coefficients. This non-uniqueness problem for CW has been demonstrated mathematically by Arridge et al. (Optics Letters Vol. 23, No.
  • TECHNICAL FIELD This invention relates to the field of optical imaging. More specifically the invention relates to the field of optical imaging of homogeneous or inhomogeneous turbid media such as biological tissue using continuous wave (CW) measurements.
  • CW continuous wave
  • TPSF based approaches are well suited for extracting absorption coefficients but the approach relies on expensive and complex hardware and software in order to perform the TPSF-based measurements. It is recognized that CW techniques are less expensive and simpler than the TPSF-based approach. However, it is well-known that the CW approach can only measure the attenuation coefficient and cannot decouple this into the absorption and scattering coefficients. This non-uniqueness problem for CW has been demonstrated mathematically by Arridge et al. (Optics Letters Vol. 23, No.
  • TPSF-based approach in the frequency domain in order to measure the absorption and scattering coefficients of a selected type of tissue providing a homogenous medium at a few near infrared (NIR) wavelengths.
  • NIR near infrared
  • they derive the scattering coefficient over a wide wavelength range by fitting this law to the scattering coefficients at the few wavelengths measured by the TPSF-based approach. This is different than actually measuring the scattering coefficient over the complete wavelength range and therefore avoids the long acquisition time of TPSF-based information at all wavelengths of interest.
  • a CW approach is then used to derive the attenuation coefficient over this wavelength range.
  • a method and system for modeling an attenuation signal arising from the attenuation of a light beam injected into biological tissue is provided.
  • the method allows for the determination of concentrations of chromophores within the tissue without the need of acquiring time point spread function (TPSF) based information.
  • TPSF time point spread function
  • a method for determining concentration of one or more chromophores in a turbid medium comprising: measuring an attenuation signal using continuous wave (CW) at a predetermined number of wavelengths; providing a scatter law in which scatter is a function of wavelength; estimating scatter parameters of the provided scatter law and a concentration for the one or more chromophores, the chromophores having a predetermined relationship between chromophore absorption and concentration as a function of wavelength; calculating attenuation values at the predetermined wavelengths using the estimated concentrations and scatter parameters; adjusting the concentration for the one or more chromophores and the scatter parameters until the calculated attenuation values and the measured attenuation differ by less than a predetermined value thereby determining the concentration within the medium; and wherein the predetermined number of wavelengths is sufficient to provide a desired degree of accuracy in the determination of the concentration.
  • CW continuous wave
  • a method for optical imaging of a region of interest in a turbid medium comprising: injecting light at a predetermined number of wavelengths into the tissue at one or more injection ports; detecting the light at one or more detection ports to obtain a measured
  • DOCSOTT. 266151U attenuation function providing a scatter law; estimating a concentration for one or more chromophores and scatter parameters at a plurality of voxels in the region of interest; calculating attenuation values at the predetermined number of wavelengths using the estimated concentration and scatter parameters and a photon diffusion equation to generate a calculated attenuation function; adjusting the concentration and the scatter parameters until the calculated attenuation function and the measured attenuation function differ by less than a predetermined value; generating an image of the tissue using the adjusted concentration for the one or more chromophores at the plurality of voxels in the region of interest; and wherein a plurality of injection ports/detection ports configurations are used to measure the attenuation function.
  • a system for Continuous Wave optical imaging of a turbid medium comprising: at least one optical source for providing continuous optical energy; at least one optical detector for detecting optical energy and generating continuous data; a source/object optical coupling for coupling the optical source to a desired position on the object; a detector/object optical coupling for coupling the optical detector to a desired position on the object; an acquisition controller connected to the optical source and the optical detector for collecting the continuous data for a plurality of * source/detector geometries within a region of interest in the object; a continuous- wave photon migration model calculator for calculating attenuation values; and an estimator using the continuous data and the calculated values to estimate optical properties of the object.
  • FIG. 1 illustrates a flow chart diagram of an embodiment of the optical system in accordance with the invention
  • a method for modeling an attenuation signal arising from the attenuation of a light beam injected into biological tissue allows for the determination of concentrations of chromophores within the tissue without the need of acquiring time point spread function (TPSF) based information.
  • TPSF time point spread function
  • the method in accordance with the invention allows scatter parameters of the tissues to be estimated.
  • the integrated intensity of light injected into an object such as biological tissue is reduced as a result of absorption ( ⁇ a ) by chromophores as well as scattering ( ⁇ s ') within the object. Both processes are wavelength dependent.
  • ⁇ is a coefficient, specific to each chromophore, that incorporates the dependency of the absorption on the scattering and c is the concentration of the chromophore.
  • the absorption at each wavelength is the sum of the absorption due to each chromophore /.
  • the concentration of chromophores is estimated using a measured attenuation value obtained in CW mode and assuming a given scatter law.
  • the scatter law is assumed to be of the form A ⁇ 'B .
  • Gustav Mie developed a more general theory for spherical particles of arbitrary size, r.
  • neither laws are directly applicable to biological tissue it seems preferable to choose a scatter law of the general functional form A ⁇ "B . Taking this scatter law into consideration, the detected attenuation signal can be written:
  • ATT( i) — 3(A/r B + ⁇ i( ⁇ )Ci)exp[-(3 ⁇ i( ⁇ )Ci(A ⁇ - B + ⁇ i( ⁇ )Ci)] 1/2 r
  • the variables A, B and q are estimated and adjusted until the difference between the calculated and measured attenuation value is less than a predetermined value.
  • the coefficients ⁇ are known for the chromophores of interest determining substantially the optical properties of the object being imaged. Also, it is preferred that all the chromophores substantially contributing to the absorption signal are included in the estimation. - 6 - 9-15186-25PCT
  • a predetermined number of wavelengths may be selected based, for example, on the spectral behavior of each chromophore to optimize the sensitivity of the calculation to each chromophore.
  • the method described above can be advantageously used for estimating the spatial distribution of concentration of chromophores in non- homogeneous media such as animal tissues. This distribution can be converted into a medical image.
  • a region of interest (ROI) within the tissue can be represented by a three dimensional grid with j voxel elements.
  • the image of the ROI can be reconstructed by estimating the concentration c of one or more chromophores for each voxel element j.
  • the concentrations c are estimated based on CW measurements at a predetermined number of wavelengths to provide attenuation values, a predetermined scatter law and on a photon diffusion equation.
  • the concentration c of at least one chromophore and the scattering parameters A and B are set to initial values for all elements j of the grid.
  • the selected concentration and scatter parameters can be based on known average values for similar tissue.
  • the measured attenuation function can be compared with a bank of attenuation functions for similar tissues to find a "best match" and using the corresponding concentrations values for chromophores and scatter parameters.
  • ⁇ a and ⁇ s ' are calculated for each voxel element j.
  • the photon diffusion equation can then be used to calculate the attenuation at each of the predetermined wavelengths for the selected detector positions.
  • the calculated and measured attenuation values are
  • DOCSOTT: 266151 ⁇ l then compared and the c, and A and B can be adjusted until the difference between the measured and calculated attenuation is less than a predetermined value.
  • the scatter parameters A and B may be restricted to a constant value while c, are modified until the calculated attenuation converges to a predetermined value at which point A and B may then be modified and the process repeated until final convergence value is obtained.
  • Other optimization algorithms as would be apparent to one skilled in the art are also possible.
  • the calculation of ⁇ a using c is based on a predetermined equation defining their relationship. In particular this equation may comprise chromophore and wavelength specific coefficients.
  • variable parameters that is the concentration of the chromophores and the scatter parameters, of each grid element can be adjusted using a minimization fitting approach until the difference between the calculated and the measured attenuation functions reaches a predetermined value.
  • the attenuation function is reconstructed using an inhomogeneous model of light propagation where the problem is minimized until the solution of the equation approaches the experimental attenuation function. This provides the coefficient for the concentration of the chromophores and the scattering parameters within each voxel from which the image of the tissue can be reconstructed.
  • chromophores may include but are not limited to oxyhemoglobin, deoxyhemoglobin, water, and lipid.
  • the concentrations c are constrained to ranges of values compatible with the tissue being analyzed, i.e. physiologically realistic.
  • the scattering parameters can be constrained to a range of expected realistic values which are known a priori, such as from TPSF-based measurements. - 8 - 9-15186-25PCT
  • the concentration of at least 4 chromophores is estimated and adjusted.
  • the method of the present invention uses attenuation measurements of a continuous wave light source injected at a plurality of wavelengths into a tissue to reconstruct an optical image of the tissue.
  • Fig. 1 an embodiment of a system used to obtain attenuation measurements of light transmitted through a tissue is shown.
  • Light generated by source 10 is injected at one or more injection ports provided by the source/object optical coupling 12 and travels through the object 14, which can be animal tissue while being scattered and absorbed and exits the tissue to be detected at one or more collection ports provided by detector/object optical coupling 16. Injection and collection may be achieved using optical fibers for example.
  • the geometry of the injection and detection ports relative to the region of interest in the tissue is optimized for parameters such as sensitivity, signal intensity and the like and preferably involves a plurality of source/detector configurations.
  • the configuration of the injection/detection port combination could depend on the chromophores that are used to obtain the image.
  • Light exiting is detected at detector 18 to produce an optical signal that is used to generate attenuation values.
  • Acquisition controller 26 is used to adjust the optical source intensity as a function of the detected optical energy for optimizing signal to noise ratio.
  • a broadband light source can be detected by a simultaneous multi-wavelength detector so as to inject and detect light simultaneously for a given source-detector geometry. Data acquisition is greatly accelerated by such a system configuration.
  • Light can be injected at one wavelength at a time and detected using a detector that is not wavelength selective.
  • light can be injected using a broadband source and detected using a spectrometer or filter that detects one selected wavelength at a time.
  • DOCSOTT: 266151 ⁇ 1 A 2D or 3D image processing and display system (not shown) reads the image data from store 24 for displaying a reconstituted image of the tissue or other turbid medium. Chromophore concentrations and scatter parameters are estimated in estimator 20 using predetermined criteria. The estimated concentrations and parameters are then used to calculate ⁇ a and ⁇ s ' (as a function of wavelength) in calculator 21 using the known chromophore spectral data in store 25.
  • the resulting estimated values of ⁇ a and ⁇ s ' (as a function of wavelength) for each voxel are provided to CW photon migration model calculator 22 where calculated attenuation values (as a function of wavelength) are generated using a photon diffusion equation and compared with measured attenuation values (as a function of wavelength) to provide a comparative basis for adjusting the c, A and B.
  • concentrations, A and B thus ⁇ a and ⁇ s ' spectra
  • An acquisition controller 26 is also provided that controls acquisition by determining the wavelengths of acquisition and the source/detector configurations.

Abstract

La présente invention concerne un procédé et un système permettant de déterminer la concentration de chromophores, et de reconstruire des images en milieu trouble, notamment des tissus animaux, grâce à une approche optique à onde continue. L'approche s'appuie plus particulièrement sur des mesures de signaux d'atténuation et le calcul de concentrations de chromophores au moyen d'une loi de dispersion définie. Le système comprend un calculateur à modèle de migration des photons en ondes continues, couplé à une source optique et à un détecteur destiné à évaluer les concentrations de chromophores et les paramètres de dispersion utilisés en reconstruction d'image.
PCT/CA2004/000297 2004-03-01 2004-03-01 Imagerie optique a onde continue tenant compte d'une loi de dispersion WO2005083396A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102402795A (zh) * 2010-09-14 2012-04-04 汤姆森特许公司 估计均匀介质中光散射的方法
US8374409B2 (en) 2006-12-21 2013-02-12 Koninklijke Philips Electronics N.V. Method for optically imaging an interior of a turbid medium, method for reconstructing an image of an interior of a turbid medium, device for imaging an interior of a turbid medium, medical image acquisition device and computer program
CN104114090A (zh) * 2011-12-23 2014-10-22 通用电气公司 用于无创测量血液中的血红蛋白浓度的方法、布置、传感器和计算机程序产品
CN108139201A (zh) * 2015-11-24 2018-06-08 特鲁塔格科技公司 使用靶向空间光谱检测的标签读取

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020190212A1 (en) * 2000-12-15 2002-12-19 Boas David Alan Indirect mode imaging
US6549284B1 (en) * 1999-09-17 2003-04-15 The General Hospital Corporation Calibration methods and systems for diffuse optical tomography and spectroscopy
US20040133085A1 (en) * 2003-01-07 2004-07-08 Art Advanced Research Technologies Inc. Continuous wave optical imaging assuming a scatter-law

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6549284B1 (en) * 1999-09-17 2003-04-15 The General Hospital Corporation Calibration methods and systems for diffuse optical tomography and spectroscopy
US20020190212A1 (en) * 2000-12-15 2002-12-19 Boas David Alan Indirect mode imaging
US20040133085A1 (en) * 2003-01-07 2004-07-08 Art Advanced Research Technologies Inc. Continuous wave optical imaging assuming a scatter-law

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ARRIDGE S R AND SCHWEIGER M: "A gradient-based optimisation scheme for optical tomography", OPTICS EXPRESS, vol. 2, no. 6, 16 March 1998 (1998-03-16), pages 213 - 226, XP002303804 *
CORLU A ET AL: "Uniqueness and wavelength optimization in continuous-wave multispectral diffuse optical tomography", OPTICS LETTERS, vol. 28, no. 23, 1 December 2003 (2003-12-01), pages 2339 - 2341, XP002303803 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8374409B2 (en) 2006-12-21 2013-02-12 Koninklijke Philips Electronics N.V. Method for optically imaging an interior of a turbid medium, method for reconstructing an image of an interior of a turbid medium, device for imaging an interior of a turbid medium, medical image acquisition device and computer program
CN102402795A (zh) * 2010-09-14 2012-04-04 汤姆森特许公司 估计均匀介质中光散射的方法
CN104114090A (zh) * 2011-12-23 2014-10-22 通用电气公司 用于无创测量血液中的血红蛋白浓度的方法、布置、传感器和计算机程序产品
CN104114090B (zh) * 2011-12-23 2016-03-23 通用电气公司 用于无创测量血液中的血红蛋白浓度的方法、布置、传感器
US10092226B2 (en) 2011-12-23 2018-10-09 General Electric Company Method, arrangement, sensor, and computer program product for non-invasively measuring hemoglobin concentrations in blood
CN108139201A (zh) * 2015-11-24 2018-06-08 特鲁塔格科技公司 使用靶向空间光谱检测的标签读取

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