Methods and algorithms for optical coherence tomography-based angiography: a review and comparison.

Area of Science:

• Biomedical Imaging
• Ophthalmology
• Medical Technology

Background:

• Optical coherence tomography (OCT) angiography is a non-invasive imaging technique for visualizing microvascular networks.
• It provides volumetric data of tissue microvasculature without requiring exogenous contrast agents.
• Recent advancements have led to numerous OCT angiography algorithms for enhanced microvascular imaging.

Purpose of the Study:

• To review recent progress in OCT angiography methods and algorithms.
• To describe the physics, mathematics, and contrast mechanisms of various OCT angiography techniques.
• To evaluate and compare the performance of recently reported OCT angiography algorithms using clinical data.

Main Methods:

• Literature review of OCT angiography algorithms.
• Description of the physical and mathematical principles behind each method.
• Comparative evaluation of algorithms including optical microangiography, speckle variance, phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping.

Main Results:

• The complex OCT signal-based method demonstrated superior performance in image contrast and vessel connectivity for retinal blood flow.
• Comparison of various OCT angiography algorithms using clinical data from normal and pathological subjects.
• Identification of the most effective algorithm for microvascular network imaging.

Conclusions:

• OCT angiography is a valuable clinical tool for in vivo microvascular imaging.
• The complex OCT signal method is currently the best-performing algorithm for retinal angiography.
• Understanding and selecting appropriate OCT angiography algorithms are crucial for specific applications.