Phase-stable swept source OCT angiography in human skin using an akinetic source.
Zhe Chen1, Mengyang Liu1, Michael Minneman2
1Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
Biomedical Optics Express
|August 30, 2016
Summary
Phase difference optical coherence tomography angiography (pOCTA) offers superior noninvasive skin imaging. This advanced OCTA technique provides enhanced contrast for visualizing microvasculature, even at deeper skin layers.
Area of Science:
- Biomedical Optics
- Medical Imaging
- Ophthalmology
Background:
- Noninvasive imaging of human skin vasculature is crucial for diagnosing and monitoring various dermatological conditions.
- Traditional optical coherence tomography angiography (OCTA) methods face limitations in contrast and resolution, especially for deeper microvasculature.
- Phase-based OCTA techniques have emerged as a promising alternative for enhanced vascular visualization.
Purpose of the Study:
- To demonstrate noninvasive structural and microvascular contrast imaging of human skin in vivo using phase difference OCTA (pOCTA).
- To compare the performance of pOCTA with speckle-based OCTA for visualizing human vascular networks.
- To investigate the impact of B-scan acquisition numbers on vascular contrast in pOCTA.
Main Methods:
- Development and utilization of a pOCTA system employing a highly phase-stable, akinetic, all-semiconductor swept laser source (1340 nm central wavelength, 37 nm bandwidth, 200 kHz A-scan rate).
- Phase-sensitive detection without external phase stabilization, leveraging the laser source's inherent phase linearity and repeatability (< 2 mrad).
- Comparative analysis of pOCTA and speckle-based OCTA performance, evaluating vascular contrast with 2 versus 4 B-scans.
Main Results:
- pOCTA demonstrated superior contrast compared to speckle-based OCTA, particularly for visualizing deeper vascular details in human skin.
- The high phase stability of the akinetic source enabled decent vascular contrast with only 2 B-scans.
- Investigation into a 100 nm bandwidth akinetic laser at 1310 nm for OCT and OCTA applications was also performed.
Conclusions:
- Phase difference OCTA is a powerful noninvasive imaging modality for human skin, offering enhanced microvascular contrast.
- The developed pOCTA system, utilizing a phase-stable swept laser, provides high-quality vascular imaging with reduced data acquisition.
- pOCTA shows significant potential for clinical applications requiring detailed visualization of superficial and deep skin vasculature.
