Design of a Multimodal Imaging System and Its First Application to Distinguish Grey and White Matter of Brain Tissue. A Proof-of-Concept-Study

• Published in: Applied sciences Vol. 11; no. 11; p. 4777
• Main Authors: Heintz, Annabell, Sold, Sebastian, Wühler, Felix, Dyckow, Julia, Schirmer, Lucas, Beuermann, Thomas, Rädle, Matthias
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2021
• Subjects: Animal tissues; Axons; Biomedical materials; brightfield microscopy; darkfield microscopy; Data acquisition; Differentiation (biology); Imaging; Incident light; Lasers; Light; Light microscopy; Lipids; Mass spectrometry; Measurement techniques; Microscopy; Morphology; multimodal imaging; Neuroimaging; Optical microscopy; Polarization; polarization microscopy; Proteins; Raman spectroscopy; reflectance spectroscopy; Scientific imaging; Spectroscopy; Stains & staining; Substantia alba; Substantia grisea; Tomography; United States > US; Germany
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11114777

Multimodal imaging gains increasing popularity for biomedical applications. This article presents the design of a novel multimodal imaging system. The centerpiece is a light microscope operating in the incident and transmitted light mode. Additionally, Raman spectroscopy and VIS/NIR reflectance spectroscopy are adapted. The proof-of-concept is realized to distinguish between grey matter (GM) and white matter (WM) of normal mouse brain tissue. Besides Raman and VIS/NIR spectroscopy, the following optical microscopy techniques are applied in the incident light mode: brightfield, darkfield, and polarization microscopy. To complement the study, brightfield images of a hematoxylin and eosin (H&E) stained cryosection in the transmitted light mode are recorded using the same imaging system. Data acquisition based on polarization microscopy and Raman spectroscopy gives the best results regarding the tissue differentiation of the unstained section. In addition to the discrimination of GM and WM, both modalities are suited to highlight differences in the density of myelinated axons. For Raman spectroscopy, this is achieved by calculating the sum of two intensity peak ratios (I2857 + I2888)/I2930 in the high-wavenumber region. For an optimum combination of the modalities, it is recommended to apply the molecule-specific but time-consuming Raman spectroscopy to smaller regions of interest, which have previously been identified by the microscopic modes.