Dynamic contrast in dual-beam optical coherence tomography imaging of human skin

Imaging of metabolic and cellular activity in living tissue is of high interest and represents a prerequisite for an understanding of environmentally induced tissue changes. In this work, we present a dual-beam optical coherence tomography (OCT) instrument that is used to investigate dynamic processes of human skin samples with two different transverse resolutions. The amplitude and the phase of the OCT signal in both channels are exploited to assess these processes. The temporal evolution of dynamic processes in living skin tissue is analyzed and used to provide increased image contrast. This allows for a clear separation between the stratum corneum, the living epidermis, and the dermis that is otherwise not visible in standard OCT images of the system. Thereby, better dynamic contrast was observed using the higher resolution images. The reproducibility of the method is tested, and the imaging results are compared with data from fixated skin samples (where no dynamics were found within the living epidermis) and histology.