Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

Area of Science:

• Biomedical Engineering
• Optical Imaging
• Gastroenterology

Background:

• Current endoscopic techniques have limitations in simultaneously visualizing surface details and subsurface microstructures.
• Nondestructive imaging is crucial for in vivo assessment of biological tissues.

Purpose of the Study:

• To design and evaluate a novel side-viewing endoscope combining surface magnifying chromoendoscopy (SMC) and optical coherence tomography (OCT).
• To demonstrate the capability of the SMC-OCT endoscope for in vivo imaging of mouse colon microstructure.

Main Methods:

• Development of a 2.3-mm diameter SMC-OCT endoscope integrating a 30,000 element fiber bundle for SMC and single-mode fibers for OCT.
• Utilized distal optics including a gradient-index lens and right-angle prism for 1x magnification and a working distance of 1.58 mm.
• Achieved 3.9-µm lateral and 2.3-µm axial resolution in the OCT channel and 125 lp/mm resolution over a 0.70-mm field of view in the SMC channel.

Main Results:

• The SMC-OCT endoscope successfully performed simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging.
• High contrast crypt visualization and molecular imaging were achieved.
• Detailed cross-sectional imaging of colon microstructure was demonstrated in vivo in mouse models.

Conclusions:

• The developed SMC-OCT endoscope offers a powerful tool for advanced endoscopic imaging.
• This technology enables simultaneous high-resolution surface and subsurface analysis of biological tissues.
• Potential applications include enhanced diagnosis and molecular imaging in gastroenterology.