Quantification method to objectively evaluate the fibrous structural status of tendons based on polarization‐sensitive OCT

Abstract

Histological analysis is widely used to evaluate injured tendons; however, it has the limitation of being semi‐quantitative. Hence, we developed a quantification method to objectively evaluate the fibrous structure of tendons, exhibiting the optical property of birefringence, using polarization‐sensitive optical coherence tomography (PS‐OCT). We used a partial‐rupture rat model in which the middle 0.75 cm of the Achilles tendon was cut with a blade. Rats were sacrificed at 2, 4 or 6 weeks after the injury, and PS‐OCT and histological analyzes were performed. The PS‐OCT phase retardation images and score well represented the structural changes of the injured tendon according to the wound healing state. Therefore, the proposed novel quantification method using PS‐OCT can be used to evaluate the fibrous structural status of tendons.

Relationship between intraocular pressure-lowering effects and alterations in scleral birefringence following micropulse cyclophotocoagulation

“…[20] PS-OCT has been used to visualize various types of fibrosis-related scarring, such as dermal fibrosis, joint or tendon fibrosis, and gastrointestinal and lung fibrosis. [20][21][22][23][24] In ocular tissues, PS-OCT has been used to analyze birefringence in fibrous tissues that contain collagens with specific polarization properties, especially the cornea, sclera, and angle structures. [19,25,26] Liu et al [20] recently demonstrated that the posterior scleral birefringence value was higher in myopic eyes and showed a positive correlation with longer axial length, especially in pathologic myopia.…”

Azimuth mapping of fibrous tissue in linear dichroism-sensitive photoacoustic microscopy

“…Since several materials exhibit polarization specificity, such as that associated with birefringence, various optical imaging modalities have been used to evaluate the anisotropic characteristics qualitatively and quantitatively [1] , [2] , [3] , [4] , [5] . Polarization-sensitive optical coherence tomography (PS-OCT), polarized light microscopy (PM), and second-harmonic generation microscopy have been prominently used for tissue polarimetry and visualization of fibrous tissues in biomedical applications [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] . These polarization contrast imaging modalities can be used to observe diagnostic biomarkers, including molecular morphological and biomechanical features.…”