Wide-field Stokes polarimetric microscopy for second harmonic generation imaging.

Area of Science:

• Biomedical Optics
• Materials Science
• Histopathology

Background:

• Accurate ultrastructural analysis of large tissue areas is crucial for disease diagnosis.
• Current methods for collagen ultrastructure imaging are often time-consuming or limited in scale.

Purpose of the Study:

• To develop and validate a wide-field microscopy technique for rapid, large-area ultrastructural investigation of histology sections.
• To apply this technique for analyzing collagen organization at lung tumor margins.

Main Methods:

• Employing wide-field second harmonic generation (SHG) microscopy combined with nonlinear Stokes polarimetry.
• Acquiring Stokes vector components from various polarization states for SHG signals.
• Constructing images of polarimetric and ultrastructural parameters, including susceptibility tensor ratios and fiber orientation.

Main Results:

• Demonstrated capability for rapid imaging of large sample areas (700 μm × 700 μm).
• Observed reduced SHG intensity and increased achiral susceptibility ratio at tumor margins.
• Identified preferential orientation of collagen fibers along the tumor border.

Conclusions:

• Wide-field Stokes polarimetric SHG microscopy enables quick, large-area imaging of tissue collagen ultrastructure.
• This technique offers a promising tool for nonlinear histopathology and disease margin assessment.