Quantifying collagen structure in breast biopsies using second-harmonic generation imaging

Abstract

Quantitative second-harmonic generation imaging is employed to assess stromal collagen in normal, hyperplastic, dysplastic, and malignant breast tissues. The cellular scale organization is quantified using Fourier transform-second harmonic generation imaging (FT-SHG), while the molecular scale organization is quantified using polarization-resolved second-harmonic generation measurements (P-SHG). In the case of FT-SHG, we apply a parameter that quantifies the regularity in collagen fiber orientation and find that malignant tissue contains locally aligned fibers compared to other tissue conditions. Alternatively, using P-SHG we calculate the ratio of tensor elements (d15/d31, d22/d31, and d33/d31) of the second-order susceptibility χ2 for collagen fibers in breast biopsies. In particular, d15/d31 shows potential differences across the tissue pathology. We also find that trigonal symmetry (3m) is a more appropriate model to describe collagen fibers in malignant tissues as opposed to the conventionally used hexagonal symmetry (C6). This novel method of targeting collagen fibers using a combination of two quantitative SHG techniques, FT-SHG and P-SHG, holds promise for breast tissue analysis and applications to characterizing cancer in a manner that is compatible with clinical practice.

Multimodal evaluation of ultra-short laser pulses treatment for skin burn injuries

“…Collagen fibers orientation have been studied on ex vivo uterine cervial tissue with SHG [43] and breast tumor tissue with polarization-resolved SHG [44]. Tanaka et al found that skin burn tissue presents molten and fibrous structures of dermal collagen [41], which is consistent with our finding on Fig.…”

Techniques to assess bone ultrastructure organization: orientation and arrangement of mineralized collagen fibrils

“…On the other hand, SHG is a popular technology that has gained a lot of attention more recently, and it is regularly being used for other softer tissues such as tendon [108], cartilage [112] or intervertebral disc [110]. However, similarly to PLM, SHG cannot be employed to quantitatively determine the collagen density and, hence, to derive the DO of the fibrils, but provides the in-plane [115] and/or out-of-plane [116] orientation in a semi-quantitative way [117].…”

Ultrastructural features of collagen in thyroid carcinoma tissue observed by polarization second harmonic generation microscopy

“…These metrics provide additional information on the collagen ultrastructural characteristics that is complementary to the concentration and spatial distribution measures. Polarization-sensitive SHG microscopy has been previously applied to determine differences in normal and malignant breast tissue [8], models of ovarian cancer [9], and non-small cell lung carcinoma [7]. In this study, we use polarization-in, polarization-out (PIPO) SHG microscopy to investigate classical papillary thyroid carcinoma (cPTC) and follicular variant papillary thyroid carcinoma (FVPTC).…”