Ex Vivo Determination of Broadband Absorption and Effective Scattering Coefficients of Porcine Tissue

Abstract

A novel approach for precise determination of the optical scattering and absorption properties of porcine tissue using an optimized integrating sphere setup was applied. Measurements on several sample types (skin, muscle, adipose tissue, bone, cartilage, brain) in the spectral range between 400 nm and 1400 nm were performed. Due to the heterogeneity of biological samples, measurements on different individual animals as well as on different sections for each sample type were carried out. For all samples, we used an index matching method to reduce surface roughness effects and to prevent dehydration. The derived absorption spectra were used to estimate the concentration of important tissue chromophores such as water, oxy- and deoxyhemoglobin, collagen and fat.

Lateral Heterostructured Vis–NIR Photodetectors with Multimodal Detection for Rapid and Precise Classification of Glioma

“…The accurate judgment for the boundary and invasive growth of glioma in the brain is the premise of precise diagnosis and treatment. The cell morphology and component of the normal brain tissues and different grades of glioma are inconsistent and dynamically changing, which leads to differences in their absorption of light at different wavelengths. , Based on the sensitive photoelectric response in the wide band, our Vis–NIR photodetectors can be employed to distinguish normal tissues from glioma, as well as glioma grades.…”

“…Recently, tissue optical properties vary with the degree of cancer or tissue lesion severity, , which have the potential to aid in the diagnosis of glioma. In most cases, investigations on the tissue optics focus solely on the near-infrared (NIR) region for deep tissue penetration. , The differences of morphology and composition in different tissues can also cause the specificity of light absorption in the visible region. − It should be noted that the combination of multimodal detection covering the visible and near-infrared light is more suitable for glioma diagnosis, which facilitates guiding the surgery and therapy accurately.…”

“…Recently, tissue optical properties vary with the degree of cancer or tissue lesion severity, 13,14 which have the potential to aid in the diagnosis of glioma. In most cases, investigations on the tissue optics focus solely on the near-infrared (NIR) region for deep tissue penetration.…”

Hybrid confocal fluorescence and photoacoustic microscopy for the label-free investigation of melanin accumulation in fish scales

“…With the exception of hemoglobin, all of the typical endogenous tissue chromophores present virtually negligible absorption coefficients in the visible part of the optical spectrum when compared to melanin. For a usual PA excitation wavelength at 532 nm, melanin is characterized by an absorption coefficient of approximately 500 cm −1 43 , which is at least 3 orders higher than the respective values for lipids (~ 0.01 cm −1 ) 44 , collagen (~ 0.25 cm −1 ) 45 and elastin (~ 0.5 cm −1 ) 46 . Within this context, the high potential of PA microscopy concerning the sensitive detection of endogenous optical absorbers in tissues, has been effectively combined with several pure optical techniques in multimodal instruments, such as confocal fluorescence microscopy 47 – 49 , non-linear imaging 50 – 52 and optical coherence tomography (OCT) 53 – 56 .…”

Grading cartilage damage with diffuse reflectance spectroscopy: Optical markers and mechanical properties

“…The anisotropy factor g for each layer was fixed to 0.9 according to the published values [36][37][38]. The value of the refractive index was the same for each layer and set to 1.4 as it was estimated elsewhere [39]. Each MCML simulation was carried out for 10 7 photon packages.…”