Dual beam optical coherence tomography angiography for decoupling axial velocity gradient

Area of Science:

• Biomedical Optics
• Medical Imaging
• Angiography

Background:

• Optical coherence tomography angiography (OCTA) is crucial for visualizing microvasculature.
• Axial velocity gradients (AVG) introduce measurement errors in OCTA when blood flow is not perpendicular to the scanning beam.
• Accurate quantification of blood flow is essential for diagnosing and monitoring various medical conditions.

Purpose of the Study:

• To develop and validate a novel dual beam OCTA method to mitigate the impact of AVG on OCTA signal.
• To decouple the contribution of AVG from the decorrelation signal in OCTA.
• To improve the accuracy of OCTA-based blood flow measurements.

Main Methods:

• Implementation of a dual beam OCTA system to acquire OCTA data from two different angles.
• Development of algorithms to process dual beam OCTA data and separate AVG effects from the decorrelation signal.
• Validation of the method using phantom experiments and in vivo human skin imaging.

Main Results:

• Phantom experiments demonstrated a significant reduction in measurement uncertainty from 1.5% to 0.7% (standard deviation) using the dual beam OCTA method.
• In vivo testing on human skin confirmed that the dual beam OCTA method effectively reduces the contribution of AVG to the decorrelation signal.
• The developed method shows promise for more accurate blood flow quantification in OCTA.

Conclusions:

• The dual beam OCTA method successfully decouples AVG, enhancing measurement accuracy.
• This technique offers a potential solution to a significant limitation in current OCTA technology.
• Further research may lead to improved diagnostic capabilities using this advanced OCTA approach.