Numerical investigation of thermal response of laser-irradiated biological tissue phantoms embedded with gold nanoshells

Recent technology developments have expanded the wavelength window for biological fluorescence imaging into the shortwave infrared. We show here a mechanistic understanding of how drastic changes in fluorescence imaging contrast can arise from slight changes of imaging wavelength in the shortwave infrared. We demonstrate, in 3D tissue phantoms and in vivo in mice, that light absorption by water within biological tissue increases image contrast due to attenuation of background and highly scattered light. Wavelengths of strong tissue absorption have conventionally been avoided in fluorescence imaging to maximize photon penetration depth and photon collection, yet we demonstrate that imaging at the peak absorbance of water (near 1,450 nm) results in the highest image contrast in the shortwave infrared. Furthermore, we show, through microscopy of highly labeled ex vivo biological tissue, that the contrast improvement from water absorption enables resolution of deeper structures, resulting in a higher imaging penetration depth. We then illustrate these findings in a theoretical model. Our results suggest that the wavelength-dependent absorptivity of water is the dominant optical property contributing to image contrast, and is therefore crucial for determining the optimal imaging window in the infrared.

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Electrical impedance spectroscopy (EIS)-based evaluation of biological tissue phantoms to study multifrequency electrical impedance tomography (Mf-EIT) systems

Journal of Visualization ◽

10.1007/s12650-016-0351-0 ◽

2016 ◽

Vol 19 (4) ◽

pp. 691-713 ◽

Cited By ~ 19

Author(s):

Tushar Kanti Bera ◽

J. Nagaraju ◽

Gilles Lubineau

Keyword(s):

Impedance Spectroscopy ◽

Electrical Impedance Tomography ◽

Biological Tissue ◽

Electrical Impedance ◽

Electrical Impedance Spectroscopy ◽

Impedance Tomography ◽

Tissue Phantoms

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Classification of Biological Spectrum Based on Principal Component Cluster Analysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.605-607.2245 ◽

2012 ◽

Vol 605-607 ◽

pp. 2245-2248

Author(s):

Lian Shun Zhang ◽

Ai Juan Shi

Keyword(s):

Cluster Analysis ◽

Biological Tissue ◽

Fiber Optic ◽

Scatter Correction ◽

Principal Component ◽

Correction Method ◽

Tissue Phantoms ◽

Spectrum Feature ◽

Biological Spectrum

Spectrums of 17 biological tissue phantoms were measured using the fiber-optic spectrometer. Then, the spectrum was preprocessed by multiplicative scatter correction method to devoice the spectrum. Afterwards the features of the spectrum were extracted via principal component analysis. Ultimately, we applied cluster analysis for the spectral features. The results showed that the accumulated credibility of the first 12 spectral principal components was 99.86% for the spectrum after preprocessing; indicating that this spectrum feature extraction might be done in the case of losing no key information. And the results showed that the 17 biological tissue phantoms can be divided into four main categories according their optical features.

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Numerical investigation of plasmonic properties of gold nanoshells

10.1117/12.2080428 ◽

2015 ◽

Cited By ~ 2

Author(s):

K. Sathiyamoorthy ◽

Michael C. Kolios

Keyword(s):

Numerical Investigation ◽

Gold Nanoshells

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Scattered and Fluorescent Photon Track Reconstruction in a Biological Tissue

International Journal of Photoenergy ◽

10.1155/2014/517510 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Maria N. Kholodtsova ◽

Pavel V. Grachev ◽

Tatiana A. Savelieva ◽

Nina A. Kalyagina ◽

Walter Blondel ◽

...

Keyword(s):

Brain Tissue ◽

Biological Tissue ◽

Tumor Location ◽

Accurate Information ◽

Track Reconstruction ◽

Excitation Radiation ◽

Probing Depth ◽

Tissue Phantoms ◽

Optical Probing ◽

Fluorescent Radiation

Appropriate analysis of biological tissue deep regions is important for tumor targeting. This paper is concentrated on photons’ paths analysis in such biotissue as brain, because optical probing depth of fluorescent and excitation radiation differs. A method for photon track reconstruction was developed. Images were captured focusing on the transparent wall close and parallel to the source fibres, placed in brain tissue phantoms. The images were processed to reconstruct the photons most probable paths between two fibres. Results were compared with Monte Carlo simulations and diffusion approximation of the radiative transfer equation. It was shown that the excitation radiation optical probing depth is twice more than for the fluorescent photons. The way of fluorescent radiation spreading was discussed. Because of fluorescent and excitation radiation spreads in different ways, and the effective anisotropy factor,geff, was proposed for fluorescent radiation. For the brain tissue phantoms it were found to be0.62±0.05and0.66±0.05for the irradiation wavelengths 532 nm and 632.8 nm, respectively. These calculations give more accurate information about the tumor location in biotissue. Reconstruction of photon paths allows fluorescent and excitation probing depths determination. Thegeffcan be used as simplified parameter for calculations of fluorescence probing depth.

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