Multiscale skin imaging in vivo using optical coherence tomography

Optical coherence tomography (OCT) is a noninvasive high-resolution diagnostic imaging modality that plays an increasingly important role in dermatology. Diagnosis of skin diseases using OCT requires both cellular-level high resolution and large area skin coverage. In practice, however, there exists a trade-off between the achievable spatial resolutions and the transverse scanning range. In this study, we report a Micro-OCT (μOCT) system that is capable of providing three-dimensional images of the skin at multiple spatial scales with both cellular-level resolution (1-2 μm) mode and large area (∼ mm2) scanning mode. Specifically, in the cellular-level scanning mode, we achieve a transverse resolution of ∼1.5 μm and an axial resolution of 1.7 μm (n = 1.38) which enables the visualization of cellular-level skin microstructures. While in the large-area scanning mode, the system is capable of covering an en face imaging area reaching up to with a lateral resolution of ∼5.5 μm at a scanning speed of 60 K Alines/s. We experimentally verify the imaging capabilities of such a multiscale μOCT system including in vivo visualization of epidermal cells in the cellular-level scanning mode as well as the internal fingerprints and sweat gland ducts in the large area scanning mode. Micro-anatomical imaging at multiple spatial scales could provide comprehensive information of the skin that is valuable to disease diagnosis.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)NMRC (Natl Medical Research Council, S’pore)Accepted versio