Non-linear imaging and characterization of atherosclerotic arterial tissue using combined SHG and FLIM microscopy
Authors: Cicchi R., Matthäus C., Meyer T., Lattermann A., Dietzek B., Brehm BR., Popp J., Pavone FS.
Autors Affiliation: National Institute of Optics, National Research Council (INO-CNR), Largo E. Fermi 6 – 50125,
European Laboratory for Non-Linear Spectroscopy (LENS), University of Florence, Via Nello Carrara, 1 – 50019, Sesto Fiorentino (Firenze), Italy;
Institute of Photonic Technology (IPHT-Jena), Albert Einstein Straße 9, 07745 Jena, Germany;
Institute of Pathology, Department of Neuropathology, Jena University Hospital – Friedrich-Schiller-University, Erlanger Allee 101, 07740 Jena, Germany;
Catholic Clinic – Koblenz, Internal Medicine & Cardiology, Rudolf Virchow Str. 9, 56073 Koblenz, Germany;
Institute of Physical Chemistry and Abbe Center of Photonics– Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;
Department of Physics, University of Florence, Via Giovanni Sansone 1 – 50019, Sesto Fiorentino, Italy
Abstract: Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view, especially for what is concerning collagen content and organization because collagen plays a crucial role in plaque vulnerability. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immune-histochemical examination and a morpho-functional approach. Non-linear microscopy techniques offer the potential for providing morpho-functional information on the examined tissues in a label-free way. In this study, we employed combined SHG and FLIM microscopy for characterizing collagen organization in both normal arterial wall and within atherosclerotic plaques. Image pattern analysis of SHG images allowed characterizing collagen organization in different tissue regions. In addition, the analysis of collagen fluorescence decay contributed to the characterization of the samples on the basis of collagen fluorescence lifetime. Different values of collagen fiber mean size, collagen distribution, collagen anisotropy and collagen fluorescence lifetime were found in normal arterial wall and within plaque depositions, prospectively allowing for automated classification of atherosclerotic lesions and plaque vulnerability. The presented method represents a promising diagnostic tool for evaluating atherosclerotic tissue and has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.
Conference title: Photonics West – BIOS 2015
KeyWords: Characterization; Collagen; Diagnosis; Diseases; Fluorescence; Histology, Atherosclerotic lesions; Automated classification; Cardio-vascular disease; Functional information; Histopathological examinations; Nonlinear microscopy; Scanning microscopy; Tissue characterization, Tissue