Dynamic, volumetric, quantitative OCT angiography of the cardiovascular system in early mouse embryonic development

Biomechanical forces from early blood circulation are critical to cardiovascular development, but studying these mechanisms is limited by the lack of tools to measure flow dynamics during embryogenesis. We present a novel method for dynamic, volumetric, and quantitative blood flow analysis in mouse embryos using optical coherence tomography (OCT). By slowly scanning across the beating heart, we capture multiple cardiac cycles at each location, enabling retrospective synchronization and reconstruction of a four-dimensional (3D + time) heartbeat. Inter-heartbeat speckle variance analysis isolates the blood-filled lumen, where flow speeds are quantified using time-at-pixel data, particle size statistics, and cardiac periodicity. This technique enables detailed visualization of embryonic blood flow and may offer new insights into the biomechanical origins of congenital heart defects.