Effective scanning protocol for optical coherence tomography and angiography using a 1.6 MHz Fourier domain mode-locked laser source

Abstract

Fourier-domain mode-locked (FDML) laser sources allow OCT imaging systems with sweep rates reaching 1.6 MHz. However, physical limitations of conventional scanning systems require consideration. Resonant scanners fix imaging frequency, whereas galvanometer scanner (GS) systems require either raster scanning with large flyback that reduce usable data, or bi-directional scans that require many repeated scans. To overcome these limitations, we employed an effective 1.6 MHz stepped bi-directional scanning protocol, allowing 2 BM-scan OCT-angiography (OCTA) imaging using high-speed FDML. We present the ideal acquisition protocol and processing algorithm for optimum OCTA quality, with results demonstrating high vasculature contrast at 1.6 MHz scan rates.