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Journal ArticleDOI

A review of the optical properties of biological tissues

TL;DR: The known optical properties (absorption, scattering, total attenuation, effective attenuation and/or anisotropy coefficients) of various biological tissues at a variety of wavelengths are reviewed in this article.
Abstract: The known optical properties (absorption, scattering, total attenuation, effective attenuation, and/or anisotropy coefficients) of various biological tissues at a variety of wavelengths are reviewed. The theoretical foundations for most experimental approaches are outlined. Relations between Kubelka-Munk parameters and transport coefficients are listed. The optical properties of aorta, liver, and muscle at 633 nm are discussed in detail. An extensive bibliography is provided. >
Citations
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Journal ArticleDOI
TL;DR: Sensitive and multicolor fluorescence imaging of cancer cells under in vivo conditions are achieved and a whole-body macro-illumination system with wavelength-resolved spectral imaging is integrated for efficient background removal and precise delineation of weak spectral signatures.
Abstract: We describe the development of multifunctional nanoparticle probes based on semiconductor quantum dots (QDs) for cancer targeting and imaging in living animals. The structural design involves encapsulating luminescent QDs with an ABC triblock copolymer and linking this amphiphilic polymer to tumor-targeting ligands and drug-delivery functionalities. In vivo targeting studies of human prostate cancer growing in nude mice indicate that the QD probes accumulate at tumors both by the enhanced permeability and retention of tumor sites and by antibody binding to cancer-specific cell surface biomarkers. Using both subcutaneous injection of QD-tagged cancer cells and systemic injection of multifunctional QD probes, we have achieved sensitive and multicolor fluorescence imaging of cancer cells under in vivo conditions. We have also integrated a whole-body macro-illumination system with wavelength-resolved spectral imaging for efficient background removal and precise delineation of weak spectral signatures. These results raise new possibilities for ultrasensitive and multiplexed imaging of molecular targets in vivo.

4,634 citations

01 Jan 1995
TL;DR: A Monte Carlo model of steady-state light transport in multi-layered tissues (MCML) has been coded in ANSI Standard C; therefore, the program can be used on various computers and has been in the public domain since 1992.
Abstract: A Monte Carlo model of steady-state light transport in multi-layered tissues (MCML) has been coded in ANSI Standard C; therefore, the program can be used on various computers. Dynamic data allocation is used for MCML, hence the number of tissue layers and grid elements of the grid system can be varied by users at run time. The coordinates of the simulated data for each grid element in the radial and angular directions are optimized. Some of the MCML computational results have been verified with those of other theories or other investigators. The program, including the source code, has been in the public domain since 1992.

2,889 citations


Cites background from "A review of the optical properties ..."

  • ...10 (1983) 824-830. [Z] S.& Prahl, M. Keijzer, St. Jacques and A.J. Welch, A Monte Carlo model of light propagation in tissue, Proc. SPIE IS 5 (1989) 102-111....

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Journal ArticleDOI
TL;DR: A Monte Carlo model of steady-state light transport in multi-layered tissues (MCML) has been coded in ANSI Standard C; therefore, the program can be used on various computers as mentioned in this paper.

2,678 citations

Journal ArticleDOI
TL;DR: This review focuses on those parameters that affect image signal and background during in vivo imaging with near-infrared light and exogenous contrast agents.

2,470 citations

Journal ArticleDOI
TL;DR: An overview of the rapidly expanding field of photoacoustic imaging for biomedical applications can be found in this article, where a number of imaging techniques, including depth profiling in layered media, scanning tomography with focused ultrasonic transducers, image forming with an acoustic lens, and computed tomography using unfocused transducers are introduced.
Abstract: Photoacoustic imaging (also called optoacoustic or thermoacoustic imaging) has the potential to image animal or human organs, such as the breast and the brain, with simultaneous high contrast and high spatial resolution. This article provides an overview of the rapidly expanding field of photoacoustic imaging for biomedical applications. Imaging techniques, including depth profiling in layered media, scanning tomography with focused ultrasonic transducers, image forming with an acoustic lens, and computed tomography with unfocused transducers, are introduced. Special emphasis is placed on computed tomography, including reconstruction algorithms, spatial resolution, and related recent experiments. Promising biomedical applications are discussed throughout the text, including (1) tomographic imaging of the skin and other superficial organs by laser-induced photoacoustic microscopy, which offers the critical advantages, over current high-resolution optical imaging modalities, of deeper imaging depth and higher absorptioncontrasts, (2) breast cancerdetection by near-infrared light or radio-frequency–wave-induced photoacoustic imaging, which has important potential for early detection, and (3) small animal imaging by laser-induced photoacoustic imaging, which measures unique optical absorptioncontrasts related to important biochemical information and provides better resolution in deep tissues than optical imaging.

2,343 citations

References
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Journal ArticleDOI
TL;DR: An integrated review of the transfer of optical radiation into human skin is presented, aimed at developing useful models for photomedicine.

2,499 citations

Journal ArticleDOI
TL;DR: In this paper, the Gurevic and Judd formulas were derived from the Kubelka-Munk differential equations, and they are exact under the same conditions as in this paper, that is, when the material is perfectly dull and when the light, is perfectly diffused or if it is parallel and hits the specimen under an angle of 60° from normal.
Abstract: The system of differential equations of Kubelka-Munk, -di=-(S+K)idx+Sjdx, dj=-(S+K)jdx+Sidx(i, j⋯ intensities of the light traveling inside a plane-parallel light-scattering specimen towards its unilluminated and its illuminated surface; x⋯ distance from the unilluminated surface S, K⋯ constants), has been derived from a simplified model of traveling of light in the material. Now, without simplifying assumptions the following exact system is derived: -di=-12(S+K)uidx+12Svjdx,dj=-12(S+K)vjdx+12Suidx,u≡∫0π/2(∂i/i∂φ)(dφ/cosφ), v≡∫0π/2(∂j/j∂φ)(dφ/cosφ), φ≡angle from normal of the light). Both systems become identical when u=v=2, that is, for instance, when the material is perfectly dull and when the light, is perfectly diffused or if it is parallel and hits the specimen under an angle of 60° from normal. Consequently, the different formulas Kubelka-Munk got by integration of their differential equations are exact when these conditions are fulfilled. The Gurevic and Judd formulas, although derived in another way by their authors, may be got from the Kubelka-Munk differential equations too. Consequently, they are exact under the same conditions. The integrated equations may be adapted for practical use by introducing hyperbolic functions and the secondary constants a=12(1/R∞+R∞) and b=12(1/R∞-R∞), (R∞≡reflectivity). Reflectance R, for instance, is then represented by the formula R=1-Rg(a-b ctghbSX)a+b ctghbSX-Rg(Rg≡reflectance of the backing, X=thickness of the specimen) and transmittance T by the formula T=ba sinhbSX+b coshbSX.In many practical cases the exact formulas may be replaced by appropriated approximations.

2,322 citations

Journal ArticleDOI
TL;DR: A simple model is developed, based on the diffusion approximation to radiative transfer theory, which yields analytic expressions for the pulse shape in terms of the interaction coefficients of a homogeneous slab.
Abstract: When a picosecond light pulse is incident on biological tissue, the temporal characteristics of the light backscattered from, or transmitted through, the sample carry information about the optical absorption and scattering coefficients of the tissue. We develop a simple model, based on the diffusion approximation to radiative transfer theory, which yields analytic expressions for the pulse shape in terms of the interaction coefficients of a homogeneous slab. The model predictions are in good agreement with the results of preliminary in vivo experiments and Monte Carlo simulations.

2,242 citations

Book
01 Jan 1952

1,440 citations

Journal ArticleDOI
TL;DR: In this paper, the delta-Eddington approximation was used to calculate monochromatic radiative fluxes in an absorbing-scattering atmosphere, by combining a Dirac delta function and a two-term approximation, which overcomes the poor accuracy of the Eddington approximation for highly asymmetric phase functions.
Abstract: This paper presents a rapid yet accurate method, the “delta-Eddington” approximation, for calculating monochromatic radiative fluxes in an absorbing-scattering atmosphere. By combining a Dirac delta function and a two-term approximation, it overcomes the poor accuracy of the Eddington approximation for highly asymmetric phase functions. The fraction of scattering into the truncated forward peak is taken proportional to the square of the phase function asymmetry factor, which distinguishes the delta-Eddington approximation from others of similar nature. Comparisons of delta-Eddington albedos, transnmissivities and absorptivities with more exact calculations reveal typical differences of 0–0.022 and maximum differences of 0.15 over wide ranges of optical depth, sun angle, surface albedo, single-scattering albedo and phase function asymmetry. Delta-Eddington fluxes are in error, on the average, by no more than 0.5%0, and at the maximum by no more than 2% of the incident flux. This computationally fa...

1,075 citations