Complex-based OCT angiography algorithm recovers microvascular information superior to amplitude or phase-based algorithm in phase-stable systems.

Complex-based OCT angiography algorithm recovers microvascular information superior to amplitude or phase-based algorithm in phase-stable systems. Phys Med Biol. 2017 Oct 19;: Authors: Xu J, Song S, Li Y, Wang RK Abstract Optical coherence tomography angiography (OCTA) is increasingly becoming a popular inspection tool for biomedical imaging applications. By exploring amplitude, phase and complex information available in the OCT signals, numerous algorithms are proposed to contrast functional vessel networks with microcirculation tissue beds. However, it is not clear which algorithm delivers optimal imaging performance. Here, we investigate systematically how the amplitude and phase information would have an impact on the OCTA imaging performance, upon which to establish the relationship of amplitude and phase stability with OCT signal-to-noise ratio (SNR), time interval and particle dynamics. With either the repeated A-scan or repeated B-scan imaging protocols, the amplitude noise increases with the increase of OCT SNR, however the phase noise does the opposite, i.e. it increases with the decrease of OCT SNR. Coupled with experimental measurements, we utilize a simple Monte Carlo (MC) model to simulate the performance of amplitude, phase and complex-based algorithms for OCTA imaging, the results of which suggest that the complex-based algorithms deliver the best performance when the phase noise is < ~40 mrad. We also conduct ...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research