Quantitative analysis of diseased horse tendons using Fourier-transform- second-harmonic generation imaging

Mayandi Sivaguru, Sushmitha Durgam, Raghu Ambekar, David Luedtke, Glenn Fried, Allison Stewart, Kimani C. Toussaint

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Fourier transform-second-harmonic generation (FT-SHG) imaging is used to quantitatively assess the structural organization of collagen fibers in tendonitis-induced horse tendons. Fiber orientation, isotropy, and the ratio of forward to backward SHG signal (F/B ratio) are used to differentiate the fiber organization between the normal and diseased horse tendons. Each second-harmonic generation (SHG) image is divided into several smaller regions of interest (ROI) and the aforementioned quantitative metrics are calculated across the whole grid. ROIs are further labeled as dark (no or minimal presence of fibers), isotropic (random fiber organization), or anisotropic (regular fiber organization) regions. Results show that the normal tendon possesses minimal isotropic regions and small standard deviations in the histograms of orientation and F/B ratio, indicating an intact and highly regular fiber organization. However, the tendonitis-induced horse tendons possess higher number of dark and isotropic regions, and larger standard deviations of the measured parameters, suggesting significantly disoriented and disorganized collagen fibers. This type of quantification would be highly beneficial in diagnosing and determining the stage of tendonitis in clinical settings. Not limited to tendonitis, the technique could also be applied to other diseases that structurally affect collagen fibers. The advantage of FT-SHG over the conventional polarization microscopy is also discussed.

Original languageEnglish (US)
Title of host publicationMultiphoton Microscopy in the Biomedical Sciences XI
StatePublished - May 5 2011
EventMultiphoton Microscopy in the Biomedical Sciences XI - San Francisco, CA, United States
Duration: Jan 23 2011Jan 25 2011

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherMultiphoton Microscopy in the Biomedical Sciences XI
Country/TerritoryUnited States
CitySan Francisco, CA


  • Collagen
  • Image analysis
  • Polarization microscopy
  • Second-harmonic generation microscopy
  • Tendonitis

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Quantitative analysis of diseased horse tendons using Fourier-transform- second-harmonic generation imaging'. Together they form a unique fingerprint.

Cite this