Quantitative analysis of forward and backward second-harmonic images of collagen fibers using Fourier transform second-harmonic-generation microscopy.

Laboratory for Photonics Research of Bio/nano Environments (PROBE), Department of Electrical and Computer Engineering,University of Illinois Urbana-Champaign, 1406 W Green Street, Urbana, Illinois 61801, USA.
Optics Letters (Impact Factor: 3.39). 12/2009; 34(24):3779-81. DOI: 10.1364/OL.34.003779
Source: PubMed

ABSTRACT Fourier transform second-harmonic generation (SHG) microscopy has been applied to quantitatively compare the information content between SHG images obtained from the forward and backward direction for three tissue types: porcine tendon, sclera, and ear cartilage. Both signal types yield consistent information on the preferred orientation of collagen fibers. For all specimens, the Fourier transform of the forward and backward SHG images produces several overlapping peaks in the magnitude spectrum at various depths into the tissues, indicating that some information present in the forward SHG images can be extracted from the backward SHG images. This study highlights the potential of backward SHG microscopy for medical diagnostics.

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