title: A spectral approach for the quantitative description of cardiac collagen network from nonlinear optical imaging.
abstract: The assessment of collagen structure in cardiac pathology, such as atrial fibrillation (AF), is essential for a complete understanding of the disease. This paper introduces a novel methodology for the quantitative description of collagen network properties, based on the combination of nonlinear optical microscopy with a spectral approach of image processing and analysis. Second-harmonic generation (SHG) microscopy was applied to atrial tissue samples from cardiac surgery patients, providing label-free, selective visualization of the collagen structure. The spectral analysis framework, based on 2D-FFT, was applied to the SHG images, yielding a multiparametric description of collagen fiber orientation (angle and anisotropy indexes) and texture scale (dominant wavelength and peak dispersion indexes). The proof-of-concept application of the methodology showed the capability of our approach to detect and quantify differences in the structural properties of the collagen network in AF versus sinus rhythm patients. These results suggest the potential of our approach in the assessment of collagen properties in cardiac pathologies related to a fibrotic structural component.
authors.forename: Michela
authors.initials: M
authors.lastname: Masè
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cristoforetti
authors.forename: Laura
authors.initials: L
authors.lastname: Avogaro
authors.forename: Francesco
authors.initials: F
authors.lastname: Tessarolo
authors.forename: Federico
authors.initials: F
authors.lastname: Piccoli
authors.forename: Iole
authors.initials: I
authors.lastname: Caola
authors.forename: Carlo
authors.initials: C
authors.lastname: Pederzolli
authors.forename: Angelo
authors.initials: A
authors.lastname: Graffigna
authors.forename: Flavia
authors.initials: F
authors.lastname: Ravelli
mesh_terms: D000465:Algorithms; D001281:Atrial Fibrillation / Q000378:metabolism / Q000473:pathology; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D005109:Extracellular Matrix; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D036641:Microscopy, Fluorescence, Multiphoton; D061848:Optical Imaging
chemical_list: D003094:Collagen