Fig. 3

ET-OCT images of eustachian tube in vivo and ex vivo (right ET). Image obtained from ET pharyngeal opening (A) and ET lumen lower segment. (B) in vivo. A, vessel demonstrates a circular signal-poor region (inset, arrow). B. Epithelium and submucosa can be shown (inset). Image obtained from ET pharyngeal opening. (C) and ET lumen lower segment. (D) in ex vivo. C, multiple glands with low signal areas (white arrow) and a slightly low signal area (circle) are seen in the submucosa. D, larger gland with low signal areas (white arrow) and slightly low signal area (asterisk) are seen in the submucosa. Cartilage (red arc), ab, epithelia, bc, subepithelial