High-Resolution Fourier Transform Infrared (FT-IR) Spectroscopic Imaging for Detection of Lung Structures and Cancer-Related Abnormalities in a Murine Model

Abstract

Label-free molecular imaging is a promising utility to study tissues in terms of the identification of their compartments as well as chemical features and alterations induced by disease. The aim of this work was to assess if higher magnification of optics in the FTIR microscope coupled with the focal plane detector (FPA) resulted in better resolution of lung structures and if the histopathological features correlated with clustering of spectral images. FTIR spectroscopic imaging was performed on paraffinized lung tissue sections from mice with optics providing a total magnification of 61× and 36×. Then, IR images were subjected to unsupervised cluster analysis and, subsequently, cluster maps were compared with hematoxylin and eosin staining of the same tissue section. Based on these results, we observed minute features such as cellular compartments in single alveoli and bronchiole, blood cells and megakaryocytes in a vessel as well as atelectasis of the lung. In the case of the latter, differences in composition were also noted between the tissue from the non-cancerous and cancerous specimen. This study demonstrated the ability of high-definition FTIR imaging to evaluate the chemical features of well-resolved lung structures that could complement the histological examination widely used in animal models of disease.

Endothelial-mesenchymal transition induced by metastatic 4T1 breast cancer cells in pulmonary endothelium in aged mice

“…Spectral distances were computed as D-values, and the individual clusters were extracted according to Ward’s algorithm. ROIs were segmented into the regions of atelectasis with low lung airiness, parenchyma with normal airways and thin-walled alveoli, and fibrous/muscular tissue according to a previously reported protocol ( Augustyniak et al, 2021 ). The classification was based on their characteristic spectral profile and confirmed by H&E staining.…”

Chemometric-empowered spectroscopic techniques in pharmaceutical fields: A bibliometric analysis and updated review

“…The application ranged from detecting cancer to the most recent infectious disease -coronavirus 2019 (COVID-19) [35,36]. As a complementary technique, imaging FTIR in combination with PCA and unsupervised hierarchical cluster analysis Original Research (UHCA) was used to detect lung cancer in animal tissue, giving a comprehensive outlook on histological images [37]. Sometimes the methods were combined with HPLC to provide more comprehensive metabolomic data [38].…”