Anisotropy in the absorption and scattering spectra of chicken breast tissue

Abstract

Oblique incidence reflectometry is a simple and accurate method for measuring the absorption and the reduced-scattering coefficients of turbid media. We used this technique to deduce absorption and reduced-scattering spectra from wavelength-resolved measurements of the relative diffuse reflectance profile of white light as a function of source-detector distance. In this study, we measured the absorption and the reduced-scattering coefficients of chicken breast tissue in the visible range ͑400 -800 nm͒ with the oblique incidence probe oriented at 0°and 90°relative to the muscle fibers. We found that the deduced optical properties varied with the probe orientation. Measurements on homogenized chicken breast tissue yielded an absorption spectrum comparable with the average of the absorption spectra for 0°and 90°probe orientations measured on the unhomogenized tissue. The reduced-scattering spectrum for homogeneous tissue was greater than that acquired for unhomogenized tissue taken at either probe orientation. This experiment demonstrated the application of oblique-incidence, fiber-optic reflectometry to measurements on biological tissues and the effect of tissue structural anisotropy on optical properties.

Performance benchmarks of an array-based hand-held photoacoustic probe adapted from a clinical ultrasound system for non-invasive sentinel lymph node imaging

“…The measured penetration depth for 1/e decay in chicken breast tissue is approximately 1.16 cm, which matches well with the value reported in the literature (approx. 1.13 cm) at an optical wavelength of 650 nm [15]. The 5 cm penetration depth (approx.…”

Imaging 2D optical diffuse reflectance in skeletal muscle

“…On one hand, an increase in sarcomere length can alter the scattering phase function and scatter more light toward fiber orientation [22]. On the other hand, the decrease in fiber diameter may reduce the scattering cross section [15], which reduced the probability that light being scattered away from the fiber orientation. More studies are necessary to elucidate the detailed mechanism.…”

“…Because of the inherent fibrous structure, light propagation in muscle is anisotropic [14], and optical properties of muscle depend on measurement orientation [15,16]. More importantly, our recent studies [17] have found that light scattering in bulk muscle is strongly affected by sarcomere structure.…”

Stereoscopic imaging through scattering media

“…5 The thicknesses of the rear tissue T 1 and the front tissue T 2 , were approximately 3 and 4.5 mm, respectively. The reference point was created by placing a pinhole with an adjustable aperture at a short distance (22 mm) behind tissue T 2 , between T 2 and the MLAs.…”