Artifacts in Optical coherence tomography angiography

Optical coherence tomography angiography (OCTA) is a functional extension of optical coherence tomography (OCT) that uses blood flow-induced signal variation as the intrinsic contrast mechanism to differentiate vasculature from static tissues. It requires taking repeat cross-sectional B-frames at the same position and assessing the change in the OCT signal in each pixel of the B-frame over the multiple scans. Pixels corresponding to vasculature show fluctuations in the OCT signal as a result of flowing blood cells while pixels of static tissue show little change. OCTA algorithms differ in how they assess the change and what part of the complex OCT signal (amplitude, phase, or amplitude and phase) is assessed.