Phase and Texture Characterizations of Scar Collagen Second-Harmonic Generation Images Varied with Scar Duration

Abstract

This work developed a phase congruency algorithm combined with texture analysis to quantitatively characterize collagen morphology in second-harmonic generation (SHG) images from human scars. The extracted phase and texture parameters of the SHG images quantified collagen directionality, homogeneity, and coarseness in scars and varied with scar duration. Phase parameters showed an increasing tendency of the mean of phase congruency with scar duration, indicating that collagen fibers are better oriented over time. Texture parameters calculated from local difference local binary pattern (LD-LBP) and Haar wavelet transform, demonstrated that the LD-LBP variance decreased and the energy of all subimages increased with scar duration. It implied that collagen has a more regular pattern and becomes coarser with scar duration. In addition, the random forest regression was used to predict scar duration, demonstrating reliable performance of the extracted phase and texture parameters in characterizing collagen morphology in scar SHG images. Results indicate that the extracted parameters using the proposed method can be used as quantitative indicators to monitor scar progression with time and can help understand the mechanism of scar progression.

Navigating the Collagen Jungle: The Biomedical Potential of Fiber Organization in Cancer

“…A number of groups, including our own, have investigated the best computational approaches to quantify changes in collagen fiber organization in a wide range of biomedical applications. The main features that were found to be meaningful to date are collagen fiber amount or density [57,58], orientation and anisotropy of orientations (or alignment) [46,59], individual fiber properties including angle, width, length and curvature, texture analysis-based collagen fiber patterns [10,[60][61][62], fiber network branching [63], and features related to combined analysis of collagen fibers and their associated tumor cells such as tumor-associated collagen signatures [8,46,64]. Among all of these features, collagen fiber orientation and alignment were of most interest to investigators.…”

Muscular and Tendon Degeneration after Achilles Rupture: New Insights into Future Repair Strategies

“…Second-harmonic generation (SHG) is a non-linear microscopy modality highly sensitive to the collagen fibril/fiber structure [ 30 ]. Thus, we used SHG to obtain structural information on the assembly of collagen fibers in the Achilles tendon after rupture, in the tendon itself and at its insertion into the gastrocnemius.…”

Texture analysis of second‐harmonic‐generation images for quantitative analysis of reticular dermal collagen fibre in vivo in human facial cheek skin

“…Also, the grey‐level co‐occurrence matrix (GLCM) analysis of SHG images was applied for classification of different tissues based on the evaluation of geometrical arrangement of collagen fibrillar bundles . Furthermore, more complicated SHG texture analysis based on local difference local binary pattern and Haar wavelet transform enables us to quantify collagen directionality, homogeneity and coarseness in scars and varied with scar duration . These SHG texture analyses highlight a potential for classification of different types of tissues, diseased tissues (eg healthy dermis and cancer dermis) or largely alternated tissues (eg healthy dermis, normal scars and keloids); however, it is unknown whether those analyses are sensitive to small alternation of dermal collagen fibres (eg normal dermis, intrinsic‐aging dermis) or not.…”