Figure 2.

Normal thyroid demonstrates well-organized round to oval thyroid follicles (F). Colloid with various densities was observed under (a) en face OCT and (b) OCM, obtained about 100 and 50 μm below the tissue surface respectively, as different signal strength. The follicles are lined by a single layer of epithelium (arrows), which are clearly seen in the OCM image (b). (c) and (d) are corresponding HE slides (4 and 20×, respectively). Scale bars, 500 μm in (a) and (c), and 100 μm in (b) and (d).