Measurement of multispectral scattering properties in mouse brain tissue

Abstract

Abstract:We present the scattering properties of mouse brain using multispectral diffraction phase microscopy. Typical diffraction phase microscopy was incorporated with the broadband light source which offers the measurement of the scattering coefficient and anisotropy in the spectral range of 550-900 nm. The regional analysis was performed for both the myeloarchitecture and cytoarchitecture of the brain tissue. Our results clearly evaluate the multispectral scattering properties in the olfactory bulb and corpus callosum. The scattering coefficient measured in the corpus callosum is about four times higher than in the olfactory bulb. It also indicates that it is feasible to realize the quantitative phase microscope in near infrared region for thick brain tissue imaging.

Multiline orthogonal scanning temporal focusing (mosTF) microscopy for scattering reduction in in vivo brain imaging

“…The mean free path length at 532 nm is about 43.5–58.8 µm calculated from the reported scattering parameters measured in vitro 26 – 28 . The anisotropy of mouse brain tissue is about 0.98 according to previous work 29 . These values inform our choice of intralipid concentration and thickness to mimic brain scattering.…”

Characterization of color cross-talk of CCD detectors and its influence in multispectral quantitative phase imaging

“…The developed algorithm with some advancement can be further employed for the multispectral quantitative phase imaging of various industrial and biological specimens. The benchmarking of color crosstalk in the detector will be useful for multi-spectral quantitative phase imaging of tissues sections that exhibit strong auto-fluorescence signatures at different wavelengths [27]. The present study may also find useful applications in pulse oximetry, currently, being used to provide important information about tissue perfusion, oxygenation and potentially function during surgery [28,29].…”

Fiberoptic hemodynamic spectroscopy reveals abnormal cerebrovascular reactivity in a freely moving mouse model of Alzheimer’s disease

“…The rationale for this wavelength range is that the optical penetration is restricted to the superficial brain layers including the cortex and that the range includes multiple isosbestic points of the hemoglobin absorption curve so it is rich in information content regarding hemoglobin saturation. Regarding the superficial penetration, our visible light at approximately 600 nm penetrated to a depth of the MFP, which is 0.39 mm (Equation 2) whereas optical scattering properties of mouse brain tissue at the 950 nm near infrared wavelength are less diffusing, with a deeper sampling (Min et al, 2017).…”

“…Compared to fMRI, fiberoptic spectroscopy is inexpensive and portable and offers a higher temporal resolution. While the Near-Infrared light (650-950 nm) used in fNIRS is capable of penetrating several centimeters through brain tissue to capture human brain structures accurately (Min et al, 2017;Pinti et al, 2020), we chose a relatively narrow spectral range (540-650 nm) because the penetration is more superficial (~0.39 mm due to higher scattering) and our chosen range contains not only multiple isobestic points in the hemoglobin absorption spectra for oxygenated vs. de-oxygenated around 550 nm, but also a point around 640 nm where absorption by oxyhemoglobin is 10-fold lower than absorption by deoxyhemoglobin. Our method offers measurement in a banana-shaped volume between a source fiber that illuminates the brain surface and a radiallydisplaced detector fiber (see Supplementary Figure 1).…”