Dual-band optical coherence tomography using a single supercontinuum laser source

Area of Science:

• Biomedical Optics
• Ophthalmology
• Medical Imaging

Background:

• Optical Coherence Tomography (OCT) is a crucial non-invasive imaging modality.
• Dual-band OCT systems offer expanded capabilities by combining different spectral ranges.
• Visible-light (Vis) OCT is emerging for specific applications, while Near-Infrared (NIR) OCT is well-established.

Purpose of the Study:

• To develop and benchmark a simultaneous Vis- and NIR-OCT system using a single supercontinuum laser.
• To compare the performance of Vis-OCT and NIR-OCT for in vivo rodent eye imaging.
• To evaluate the capability of each subsystem for anatomical imaging, angiography, blood flow, and blood oxygen saturation (sO2) measurements.

Main Methods:

• A single supercontinuum laser source was utilized to create simultaneous Vis- and NIR-OCT subsystems.
• Vis-OCT operated with a 91 nm bandwidth centered at 566 nm (1.8 μm axial resolution).
• NIR-OCT operated with a 93 nm bandwidth centered at 841 nm (4.4 μm axial resolution).
• In vivo rodent models were used for comparative performance analysis.

Main Results:

• Both Vis-OCT and NIR-OCT subsystems demonstrated comparable performance in anatomical imaging, angiography, and absolute retinal blood flow measurements.
• Minor discrepancies were observed between the subsystems, attributed to their operational wavelengths.
• Retinal blood oxygen saturation (sO2) could only be successfully retrieved using the Vis-OCT subsystem.

Conclusions:

• The developed simultaneous Vis- and NIR-OCT system is effective for multimodal retinal imaging.
• Vis-OCT offers unique capabilities, such as in vivo sO2 measurement, not achievable with conventional NIR-OCT.
• This technology holds promise for advanced ophthalmic diagnostics and research.