Skin cancer is the most common form of cancer in North America, and melanoma is the most deadly form of skin cancer.Roughness assessment of epidermis has been shown to be valuable in detecting potential skin neoplasia. However, theexisting roughness assessment techniques cannot also provide volumetric information. For greater insight, we proposepolarization sensitive optical coherence tomography (PS-OCT) for skin assessment. The intensity channel of OCTvisualizes the layered structure and surface roughness profile of skin in 3D. Furthermore, PS-OCT can simultaneouslyconduct polarization related measurements such as the degree of polarization uniformity (DOPU) in a separate imagingchannel. Skin phantoms of different surface roughness ranging from 1 to 68 μm have been studied. It was observed thatfor rougher surfaces, the roughness can be quantified from the surface profile visible in the intensity channel. In smoothersurfaces for which the profile is not sensitive, the DOPU decreases with roughness in a quantifiable correlation. Thecontrast in the DOPU channel is sensitive to polarization and phase fluctuations. Smoother surfaces tend to maintain thepolarization state, whereas the height differences in a rougher surface contribute to larger phase shifts between light waveswithin the coherence volume, leading to greater depolarization. PS-OCT was also applied to in vivo imaging of humanskin. The skin at the palm edge shows lower DOPU compared to the skin on the back of the hand, an indication of greaterpolarization state modification caused by skin roughness. PS-OCT can provide a comprehensive evaluation of skin, whichhas great potential for detecting melanoma.
展开▼
