Increasing the imaging depth of spectral-domain OCT by using interpixel shift technique.

Area of Science:

• Biomedical Optics
• Medical Imaging Technology
• Ophthalmic Imaging

Background:

• Spectral-domain optical coherence tomography (SDOCT) is a crucial non-invasive imaging modality.
• Enhancing SDOCT's axial resolution and signal-to-noise ratio (SNR) is vital for detailed biological tissue analysis.
• Existing SDOCT techniques face limitations in achieving high resolution and deep tissue penetration simultaneously.

Purpose of the Study:

• To introduce a simple pixel shift technique to improve SDOCT performance.
• To enhance the spectral sampling rate and signal-to-noise ratio (SNR) in the 1.3 µm wavelength range.
• To validate the technique through theoretical analysis and experimental comparisons.

Main Methods:

• Implementation of a pixel shift strategy within the SDOCT system.
• Theoretical modeling to predict the impact of pixel shifting on spectral sampling and SNR.
• Experimental validation comparing standard SDOCT with the proposed interpixel shifted SDOCT.

Main Results:

• The pixel shift technique successfully doubled the spectral sampling rate.
• Significant enhancement in the signal-to-noise ratio (SNR) was observed.
• The interpixel shifted SDOCT demonstrated a doubled depth of field and elimination of aliasing artifacts.
• Improved image contrast was achieved, particularly in regions with large depths (≥ 1.5 mm).

Conclusions:

• The proposed interpixel shifted SDOCT technique offers a simple yet effective method to enhance imaging capabilities.
• This advancement can improve the in vivo diagnosis of biological tissues, especially for conditions requiring visualization of deeper structures.
• Potential applications include enhanced imaging of cartilage degeneration and bladder tumors with complex morphologies.