Scoring of collagen organization in healthy and diseased human dermis by multiphoton microscopy

We have used nonlinear imaging to evaluate collagen organization in connective tissue ex-vivo samples. Image analysis methods were tested on healthy dermis, normal scars, and keloids. The evaluation of the second harmonic to autofluorescence aging index of dermis (SAAID) has allowed a first characterization of tissues by scoring the collagen/elastin content. Further analyses on collagen morphology in healthy dermis and keloids were performed by image-pattern analysis of SHG images. The gray-level co-occurrence matrix (GLCM) analysis method has allowed classification of different tissues based on the evaluation of geometrical arrangement of collagen fibrillar bundles, whereas a pattern analysis of the FFT images has allowed the discrimination of different tissues based on the anisotropy of collagen fibers distribution, This multiple scoring method represents a promising tool to be extended to other collagen disorders, as well as to be used in in-vivo skin-imaging applications. [GRAPHICS] Slice of a sample of keloid labeled with H&E staining and imaged using nonlinear microscopy. Field of view: 1 x 0.5 mm (C) 2010 by WILEY-VCH Verlag GmbH & Co. KGaA. Weinheim