Accessing depth-resolved high spatial frequency content from the optical coherence tomography signal.

Area of Science:

• Biomedical Imaging
• Optical Physics
• Cell Biology

Background:

• Conventional optical coherence tomography (OCT) offers depth-resolved imaging with 5-10 micron resolution.
• Pathological processes often involve structures smaller than conventional OCT can detect.
• Enhanced sensitivity is crucial for early disease detection and functional biological imaging.

Purpose of the Study:

• To analyze the spatial frequency content of OCT signals using scattering theory.
• To demonstrate the capability of OCT to detect sub-wavelength structures.
• To improve OCT's sensitivity to nanoscale structural alterations in biological tissues.

Main Methods:

• Analysis of spatial frequency content in OCT signals based on scattering theory.
• Experimental imaging of phantoms with known sub-micron structures.
• Visualization of nanoscale changes in mesenchymal stem cells (MSC).

Main Results:

• OCT signals contain information about high spatial frequencies, enabling detection of sub-wavelength structures.
• Experimental validation using phantoms confirmed the theoretical predictions.
• Nanoscale structural changes within MSCs, undetectable by conventional OCT, were visualized.

Conclusions:

• The study provides a theoretical and experimental foundation for extracting high spatial frequency information from OCT signals.
• This approach significantly enhances OCT's sensitivity to structural alterations at the nanoscale.
• The findings pave the way for improved diagnostic capabilities in biomedical imaging.