Tissue characterization using axicon probe-assisted common-path optical coherence tomography.

Area of Science:

• Biomedical Optics
• Optical Engineering
• Medical Imaging

Background:

• Optical coherence tomography (OCT) is a valuable tool for non-invasive tissue characterization.
• Traditional OCT systems often require bulky microscopic lenses for high-resolution imaging.
• Characterizing tissue optical properties is crucial for disease diagnosis.

Purpose of the Study:

• To demonstrate a common-path OCT system utilizing a novel fiber-tip probe.
• To characterize tissue optical properties for differentiating normal from cancerous tissues.
• To assess the potential of the system for endoscopic or minimally invasive inspections.

Main Methods:

• A negative axicon structure chemically etched into a fiber tip was used as an optical probe.
• The probe generated a Bessel beam with a large depth-of-field (∼700 µm) and small spot size (∼3 µm).
• The OCT system imaged chicken tissue and human liver/pancreas samples without external microscopic lenses.

Main Results:

• The OCT system successfully obtained images of chicken tissue.
• Refractive index and optical attenuation coefficients were estimated from the OCT data.
• Cancerous human liver and pancreas tissues were differentiated from normal tissues based on imaging and optical properties.

Conclusions:

• The developed fiber-tip Bessel beam probe enables effective OCT imaging and optical property characterization.
• The system shows promise for distinguishing cancerous from normal tissues.
• This technology could be instrumental in early-stage malignancy detection and intraoperative assessment.