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Grabtchak S, Montgomery LG, Pang B, Wang Y, Zhang C, Li Z, Xia Y, Whelan WM. Interstitial diffuse radiance spectroscopy of gold nanocages and nanorods in bulk muscle tissues. Int J Nanomedicine 2015; 10:1307-20. [PMID: 25709450 PMCID: PMC4335609 DOI: 10.2147/ijn.s79246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Radiance spectroscopy was applied to the interstitial detection of localized inclusions containing Au nanocages or nanorods with various concentrations embedded in porcine muscle phantoms. The radiance was quantified using a perturbation approach, which enabled the separation of contributions from the porcine phantom and the localized inclusion, with the inclusion serving as a perturbation probe of photon distributions in the turbid medium. Positioning the inclusion at various places in the phantom allowed for tracking of photons that originated from a light source, passed through the inclusion's location, and reached a detector. The inclusions with high extinction coefficients were able to absorb nearly all photons in the range of 650-900 nm, leading to a spectrally flat radiance signal. This signal could be converted to the relative density of photons incident on the inclusion. Finally, the experimentally measured quantities were expressed via the relative perturbation and arranged into the classical Beer-Lambert law that allowed one to extract the extinction coefficients of various types of Au nanoparticles in both the transmission and back reflection geometries. It was shown that the spatial variation of perturbation could be described as 1/r dependence, where r is the distance between the inclusion and the detector. Due to a larger absorption cross section, Au nanocages produced greater perturbations than Au nanorods of equal particle concentration, indicating a better suitability of Au nanocages as contrast agents for optical measurements in turbid media. Individual measurements from different inclusions were combined into detectability maps.
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Affiliation(s)
- Serge Grabtchak
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
- Departments of Electrical and Computer Engineering, and Physics, Dalhousie University, Halifax, Canada
| | - Logan G Montgomery
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - Bo Pang
- Department of Biomedical Engineering, Peking University, Beijing, People’s Republic of China
- The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Yi Wang
- The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Key Laboratory of Green Synthesis and Applications, College of Chemistry, Chongqing Normal University, Chongqing, People’s Republic of China
| | - Chao Zhang
- Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People’s Republic of China
- College of Physics and Optoelectronics, South China University of Technology, Guangzhou, People’s Republic of China
| | - Zhiyuan Li
- Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, People’s Republic of China
- College of Physics and Optoelectronics, South China University of Technology, Guangzhou, People’s Republic of China
| | - Younan Xia
- The Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- School of Chemistry and Biochemistry, and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - William M Whelan
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
- Atlantic Veterinary College, Charlottetown, PEI, Canada
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Grabtchak S, Montgomery LG, Whelan WM. Optical absorption and scattering properties of bulk porcine muscle phantoms from interstitial radiance measurements in 650-900 nm range. Phys Med Biol 2014; 59:2431-44. [PMID: 24743553 DOI: 10.1088/0031-9155/59/10/2431] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We demonstrated the application of relative radiance-based continuous wave (cw) measurements for recovering absorption and scattering properties (the effective attenuation coefficient, the diffusion coefficient, the absorption coefficient and the reduced scattering coefficient) of bulk porcine muscle phantoms in the 650-900 nm spectral range. Both the side-firing fiber (the detector) and the fiber with a spherical diffuser at the end (the source) were inserted interstitially at predetermined locations in the phantom. The porcine phantoms were prostate-shaped with ∼4 cm in diameter and ∼3 cm thickness and made from porcine loin or tenderloin muscles. The described method was previously validated using the diffusion approximation on simulated and experimental radiance data obtained for homogenous Intralipid-1% liquid phantom. The approach required performing measurements in two locations in the tissue with different distances to the source. Measurements were performed on 21 porcine phantoms. Spectral dependences of the effective attenuation and absorption coefficients for the loin phantom deviated from corresponding dependences for the tenderloin phantom for wavelengths <750 nm. The diffusion constant and the reduced scattering coefficient were very close for both phantom types. To quantify chromophore presence, the plot for the absorption coefficient was matched with a synthetic absorption spectrum constructed from deoxyhemoglobin, oxyhemoglobin and water. The closest match for the porcine loin spectrum was obtained with the following concentrations: 15.5 µM (±30% s.d.) Hb, 21 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The tenderloin absorption spectrum was best described by 30 µM Hb (±30% s.d), 19 µM (±30% s.d.) HbO2 and 0.3 (±30% s.d.) fractional volume of water. The higher concentration of Hb in tenderloin was consistent with a dark-red appearance of the tenderloin phantom. The method can be applied to a number of biological tissues and organs for interstitial optical interrogation.
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Affiliation(s)
- Serge Grabtchak
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada. Departments of Electrical and Computer Engineering, and Physics, Dalhousie University, Halifax, NS B3H3J5, Canada
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Grabtchak S, Callaghan KB, Whelan WM. Tagging photons with gold nanoparticles as localized absorbers in optical measurements in turbid media. BIOMEDICAL OPTICS EXPRESS 2013; 4:2989-3006. [PMID: 24409396 PMCID: PMC3862156 DOI: 10.1364/boe.4.002989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/19/2013] [Accepted: 11/21/2013] [Indexed: 06/03/2023]
Abstract
We analyze a role of a localized inclusion as a probe for spatial distributions of migrating photons in turbid media. We present new experimental data and two-dimensional analysis of radiance detection of a localized absorptive inclusion formed by gold nanoparticles in Intralipid-1% when the target is translated along the line connecting the light source and detector. Data are analyzed using the novel analytical expression for the relative angular photon distribution function for radiance developed by extending the perturbation approach for fluence. Obtained photon maps allow predicting conditions for detectability of inclusions for which proximity to the detector is essential.
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Affiliation(s)
- Serge Grabtchak
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada
- Departments of Electrical and Computer Engineering, and Physics, Dalhousie University, Halifax, NS B3H3J5, Canada
| | - Kristen B. Callaghan
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada
| | - William M. Whelan
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada
- Atlantic Veterinary College, Charlottetown, PEI C1A4P3, Canada
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Swami MK, Patel HS, Geethu P, Uppal A, Kushwaha PK, Gupta PK. Effect of gold nanoparticles on depolarization characteristics of Intralipid tissue phantom. OPTICS LETTERS 2013; 38:2855-7. [PMID: 23903162 DOI: 10.1364/ol.38.002855] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report results of studies on the effect of different shapes and sizes of gold nanoparticles (GNPs) on the depolarization characteristics of Intralipid tissue phantoms. For a given extinction coefficient, the absorption characteristics of the GNPs contributed more to the depolarization of the turbid medium, and the contribution of scattering was significant only for the larger-sized particles. For rod-shaped GNPs, their depolarization plays an important role in the low scattering regime in which the depolarization properties of the nanoparticles (NPs) dominate in the turbid medium even if the contribution of the scattering from the NPs is about an order of magnitude less. For highly scattering samples, GNP absorption significantly modulates the depolarization spectra of the turbid medium.
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Affiliation(s)
- M K Swami
- Laser Biomedical Applications and Instrumentations Division, Raja Ramanna Centre for Advanced Technology, Indore, India
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Grabtchak S, Palmer TJ, Vitkin IA, Whelan WM. Radiance detection of non-scattering inclusions in turbid media. BIOMEDICAL OPTICS EXPRESS 2012; 3:3001-11. [PMID: 23162735 PMCID: PMC3493233 DOI: 10.1364/boe.3.003001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 05/10/2023]
Abstract
Detection of non-scattering domains (voids) is an area of active research in biomedical optics. To avoid complexities of image reconstruction algorithms and requirements of a priori knowledge of void locations inherent to diffuse optical tomography (DOT), it would be useful to establish specific experimental signatures of voids that would help identify and detect them by other means. To address this, we present a radiance-based spectro-angular mapping approach that identifies void locations in the angular domain and establishes their spectral features. Using water-filled capillaries in scattering Intralipid as a test platform, we demonstrate perturbations in the directional photon density distribution produced by individual voids.
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Affiliation(s)
- Serge Grabtchak
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
- Departments of Electrical and Computer Engineering, and Physics, Dalhousie University, Halifax, NS, Canada
| | - Tyler J. Palmer
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - I. Alex Vitkin
- Departments of Medical Biophysics and Radiation Oncology, University of Toronto and Ontario Cancer Institute/University Health Network, Toronto, ON, Canada
| | - William M. Whelan
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI, Canada
- Atlantic Veterinary College, Charlottetown, PEI, Canada
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Grabtchak S, Whelan WM. Separation of absorption and scattering properties of turbid media using relative spectrally resolved cw radiance measurements. BIOMEDICAL OPTICS EXPRESS 2012; 3:2371-80. [PMID: 23082279 PMCID: PMC3469994 DOI: 10.1364/boe.3.002371] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/27/2012] [Accepted: 08/27/2012] [Indexed: 05/10/2023]
Abstract
We present a new method for extracting the effective attenuation coefficient and the diffusion coefficient from relative spectrally resolved cw radiance measurements using the diffusion approximation. The method is validated on both simulated and experimental radiance data sets using Intralipid-1% as a test platform. The effective attenuation coefficient is determined from a simple algebraic expression constructed from a ratio of two radiance measurements at two different source-detector separations and the same 90° angle. The diffusion coefficient is determined from another ratio constructed from two radiance measurements at two angles (0° and 180°) and the same source-detector separation. The conditions of the validity of the method as well as possible practical applications are discussed.
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Affiliation(s)
- Serge Grabtchak
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada
- Department of Electrical and Computer Engineering, Dalhousie University, Halifax, NS B3J1Z1, Canada
- Department of Physics, Dalhousie University, Halifax, NS B3H3J5, Canada
| | - William M. Whelan
- Department of Physics, University of Prince Edward Island, Charlottetown, PEI C1A4P3, Canada
- Atlantic Veterinary College, Charlottetown, PEI C1A4P3, Canada
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Grabtchak S, Palmer TJ, Foschum F, Liemert A, Kienle A, Whelan WM. Experimental spectro-angular mapping of light distribution in turbid media. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:067007. [PMID: 22734785 DOI: 10.1117/1.jbo.17.6.067007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present a new approach to the analysis of radiance in turbid media. The approach combines data from spectral, angular and spatial domains in a form of spectro-angular maps. Mapping provides a unique way to visualize details of light distribution in turbid media and allows tracking changes with distance. Information content of experimental spectro-angular maps is verified by a direct comparison with simulated data when an analytical solution of the radiative transfer equation is used. The findings deepen our understanding of the light distribution in a homogenous turbid medium and provide a first step toward applying the spectro-angular mapping as a diagnostic tool for tissue characterization.
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Affiliation(s)
- Serge Grabtchak
- University of Prince Edward Island, Department of Physics, Charlottetown, PEI Canada.
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