Preclinical photoacoustic imaging endoscope based on acousto-optic coaxial system using ring transducer array

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Gastroenterology

Background:

• Colorectal cancer detection remains a critical area in medical diagnostics.
• Existing imaging modalities have limitations in sensitivity and specificity for early-stage detection.
• Photoacoustic imaging offers a promising non-invasive approach for visualizing biological tissues.

Purpose of the Study:

• To develop and fabricate a preclinical photoacoustic imaging endoscope (PAIE) for enhanced cavity imaging.
• To evaluate the PAIE's capability in reconstructing images of biological tissues.
• To assess the potential of PAIE for ex vivo colorectal cancer detection.

Main Methods:

• Fabrication of a PAIE with an acousto-optic coaxial structure, integrating a Plexiglas tube, optical fiber, ring transducer array, taper reflector, and ultrasonic coupling medium.
• Reconstruction of a photoacoustic image using a section of pig colorectal tissue embedded in a gelatin phantom.
• Ex vivo imaging of human colorectal cancer and normal colorectal tissue.

Main Results:

• Successful reconstruction of a photoacoustic image for pig colorectal tissue.
• Achieved a contrast ratio of approximately 2.3 when imaging human colorectal cancer and normal tissue ex vivo.
• Demonstrated the PAIE's ability to differentiate between cancerous and normal tissue.

Conclusions:

• The developed preclinical photoacoustic imaging endoscope (PAIE) is a viable tool for cavity imaging.
• The PAIE shows significant potential for the clinical detection of colorectal cancer.
• Further research and clinical trials are warranted to fully establish its diagnostic value.