Image Analysis of Optical Coherence Tomography Angiography

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Optical coherence tomography angiography (OCT-A) images ocular vessels by detecting blood flow, extending optical coherence tomography (OCT) capabilities.
• OCT-A provides depth-resolved visualization of microvasculature, offering functional insights beyond structural imaging.

Purpose of the Study:

• To highlight the importance of axial segmentation in OCT-A for accurate microvascular imaging.
• To discuss the challenges and solutions for segmentation errors and projection artifacts in OCT-A.

Main Methods:

• Review of OCT-A principles and imaging characteristics.
• Discussion of automated and manual segmentation algorithms for retinal and choroidal layers.
• Analysis of projection artifacts inherent to OCT-A.

Main Results:

• OCT-A enables functional imaging of ocular vasculature by detecting motion contrast from blood flow.
• Automated segmentation is common, but manual correction is necessary for complex anatomical disruptions.
• Projection artifacts from superficial vessels can obscure deeper structures or appear in unintended layers.

Conclusions:

• Accurate axial segmentation is critical for reliable OCT-A interpretation, preserving perfused structure data.
• Understanding and mitigating segmentation errors and projection artifacts are essential for high-quality OCT-A analysis.
• OCT-A is a powerful tool for visualizing ocular microvasculature, but technical considerations like segmentation and artifacts must be addressed.