Fusion of multiple dynamics-OCT contrasts for assessment of intratissue dynamics and visualization of dynamics-domain structures

Dynamic optical coherence tomography (DOCT) is an emerging label-free modality that visualizes intra-tissue activity by statistically analyzing the fluctuation of the time-sequential OCT signal. There are several variations of DOCT methods, and each of them is expected to be sensitive to different properties of intra-cellular and intra-tissue dynamics. However, most of the previous studies relied on a single type of DOCT, and this single-contrast nature limits the visibility of the dynamics structure of the tissue. In this presentation, we demonstrate a meta-contrast of DOCT, so-called “multi-dynamics OCT,” which is generated by fusing multiple types of DOCT contrasts. Notably, all the fundamental DOCT contrasts to be fused are generated by a single sequence of OCT frames. Hence, despite the multi-contrast nature of the multi-dynamic OCT, the data acquisition time is as short as that of single-contrast DOCT imaging. In addition, we numerically investigate the relationship between each fundamental DOCT contrast and the intra-tissue and intra-cellular dynamics by building mathematical models of intra-tissue and intra-cellular dynamics. It enables the interpretation of fundamental DOCT contrasts. The multi-dynamics OCT revealed complicated dynamics domains of anti-cancer-drug-treated tumor spheroids and an ex vivo mouse kidney which are obscured in previous single-contrast DOCT images. The combination of the multi-dynamics OCT image and the DOCT interpretation based on the numerical simulation enhances the subjective observation and objective interpretation ability of DOCT.