A feasibility study of an integrated NIR/gamma/visible imaging system for endoscopic sentinel lymph node mapping

Area of Science:

• Medical Imaging
• Endoscopy
• Biomedical Engineering

Background:

• Sentinel lymph node (SLN) mapping is crucial for cancer staging.
• Near-infrared (NIR) imaging has limitations in depth penetration.
• Integrating multiple imaging modalities can overcome individual limitations.

Purpose of the Study:

• To develop and assess an integrated endoscopic system combining NIR, gamma, and visible imaging.
• To overcome NIR imaging limitations using gamma imaging.
• To demonstrate the feasibility of endoscopic NIR/gamma/visible fusion imaging for SLN mapping in small animals.

Main Methods:

• An endoscopic system was constructed using a tungsten pinhole collimator, BGO crystal, fiber-optic taper, and CCD camera.
• Spatial resolution was assessed using a phantom with 99mTc and indocyanine green (ICG).
• In vivo SLN mapping was performed in mice by injecting a mixture of 99mTc-antimony sulfur colloid and ICG.

Main Results:

• The system successfully acquired NIR, gamma, and visible images of a phantom.
• In vivo and ex vivo NIR/gamma/visible fusion images of SLNs showed good correlation between modalities.
• The integrated system demonstrated feasibility for SLN mapping.

Conclusions:

• The feasibility of an integrated NIR/gamma/visible endoscopic imaging system was demonstrated.
• Future work includes endoscope head miniaturization and simultaneous multi-modal imaging.
• This technology holds promise for improved SLN mapping in preclinical research.