Gradient mapping of multi-timescale optical coherence tomography angiography signals for enhancing signal-to-noise ratio of flow detection

Optical coherence tomography (OCT) is a three-dimensional imaging technique based on low interferometry of near-infrared broadband light and has been applied to medical diagnoses, such as structural diagnosis the retina in ophthalmology. For several decades, functional variations OCT have also developed. angiography (OCTA) one can visualize blood flows (microvasculature) biological tissues by analyzing time-series signals. Recently, studies suggested possibility that OCTA not only but detect flow velocity quantitatively, where estimated signals computed with multiple time separations from measured at short interval. separations, however, reduce its contrast between dynamic (blood flows) other static tissues, resulting decrease signal-to-noise (SN) ratio detection. This study proposed novel method enhance SN detection means mapping gradient against separations. In experiments, phantom human skins were employed compare ratios among long separation (standard OCTA), separation, method. The results showed methods high equivalent standard and, therefore, quantitative will be possible