Visible to near-infrared refractive properties of freshly-excised human-liver tissues: marking hepatic malignancies

Giannios, Panagiotis; Toutouzas, Konstantinos G.; Matiatou, Maria; Stasinos, Konstantinos; Konstadoulakis, Manousos M.; Zografos, George; Moutzouris, K.

doi:10.1038/srep27910

Cited by 85 publications

(44 citation statements)

References 58 publications

(88 reference statements)

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“…For simplification, the values of the refractive index n and anisotropy g were considered to be independent from the wavelength in the 900 to 1600 nm range and equal to n ¼ 1.4 (typical values of n for the tissue from 1.35 to 1.41 8 and reviewed in Ref. 51), and anisotropy factor g ¼ 0.9 (typical values 0.80 to 0.95 52 ). The upper panel shows the distribution of the photon from the bottom view (entrance) and top view.…”

Section: Resultsmentioning

confidence: 99%

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

et al. 2016

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Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte–Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm; however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent.

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Section: Resultsmentioning

confidence: 99%

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

et al. 2016

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“…The plots obtained using Cauchy and Cornu equations do not stand well with previous publications demonstrating decreased RI as the wavelength increases. 2,17,18,31,32 As seen, along the spectrum of Figs. 5(a) and 5(b), there are minute differences between RI levels with changes in temperature.…”

Section: °C 43°cmentioning

confidence: 77%

Spectral refractive index assessment of turbid samples by combining spatial frequency near-infrared spectroscopy with Kramers–Kronig analysis

2018

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A practical algorithm for estimating the wavelength-dependent refractive index (RI) of a turbid sample in the spatial frequency domain with the aid of Kramers-Kronig (KK) relations is presented. In it, phase-shifted sinusoidal patterns (structured illumination) are serially projected at a high spatial frequency onto the sample surface (mouse scalp) at different near-infrared wavelengths while a camera mounted normally to the sample surface captures the reflected diffuse light. In the offline analysis pipeline, recorded images at each wavelength are converted to spatial absorption maps by logarithmic function, and once the absorption coefficient information is obtained, the imaginary part (k) of the complex RI (CRI), based on Maxell's equations, can be calculated. Using the data represented by k, the real part of the CRI (n) is then resolved by KK analysis. The wavelength dependence of n ( λ ) is then fitted separately using four standard dispersion models: Cornu, Cauchy, Conrady, and Sellmeier. In addition, three-dimensional surface-profile distribution of n is provided based on phase profilometry principles and a phase-unwrapping-based phase-derivative-variance algorithm. Experimental results demonstrate the capability of the proposed idea for sample's determination of a biological sample's RI value.

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“…The optical absorption and scattering phenomena strongly depend on the size of the nanoparticles and the dielectric constant of the surrounding medium. For small AuNPs in water (refractive index = 1.33 and dielectric constant = 2 ), total extinction is completely ruled by absorption; when the size increases, the scattering process appears and intensifies [20][21][22][23].…”

Section: Journal Of Nanomaterialsmentioning

confidence: 99%

“…For the media (liver or colon tissue), the complex dielectric constants were obtained following the same procedure employed for AuNP but using the complex index reported by Giannios et al [22,23]. The experimental data was used to obtain the values for the refractive index as a continuous function dependent on the wavelength.…”

Section: Complex Dielectric Constantmentioning

confidence: 99%

Study of the Optical Properties of Functionalized Gold Nanoparticles in Different Tissues and Their Correlation with the Temperature Increase

Carrillo-Cazares¹,

Jiménez-Mancilla²,

Luna-Gutiérrez³

et al. 2017

Journal of Nanomaterials

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Mie theory explains the interaction of light with a gold nanoparticle (AuNP) through the absorption ( abs ), scattering ( sca ), and extinction ( ext ) cross sections. These parameters have been calculated in the case of AuNPs dispersed in homogeneous media, but not for specific tissues. The aim of this research was to theoretically obtain the optical cross sections ( abs , sca , and ext ) of functionalized AuNPs in liver and colon tissues through Mie theory and correlate them with the temperature increase observed experimentally in tissues containing AuNPs under plasmonic photothermal irradiation using a Nd-YAG laser ( = 532 nm). Calculations showed that abs represents 98.96 ± 0.03% of ext at 532 nm. The ext value for a functionalized AuNP in water was 365.66 nm 2 (94% of the theoretical maximum value at 522.5 nm), 404.24 nm 2 in colon (98% of the theoretical maximum value at 525 nm), and 442.39 nm 2 in liver (96% of the theoretical maximum value at 525 nm). Therefore, nanoparticles irradiated at 532 nm are very close to their resonance value. These results correlated with the experimental irradiation of functionalized AuNPs in different tissues, where the average temperature increase showed the pattern liver > colon > water. The temperature increase observed (Δ up to 13 ∘ C) is sufficient to produce cellular death.

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Visible to near-infrared refractive properties of freshly-excised human-liver tissues: marking hepatic malignancies

Cited by 85 publications

References 58 publications

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

Spectral refractive index assessment of turbid samples by combining spatial frequency near-infrared spectroscopy with Kramers–Kronig analysis

Study of the Optical Properties of Functionalized Gold Nanoparticles in Different Tissues and Their Correlation with the Temperature Increase

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