Department of Electrical Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada.
Department of Head and Neck Surgery and Otolaryngology, Kosin University College of Medicine, Busan, 49267, Korea.
Tissue Eng Regen Med. 2021 Feb;18(1):81-87. doi: 10.1007/s13770-020-00323-y. Epub 2021 Jan 7.
The vocal cord tissue consists of three anatomical layers from the surface to deep inside: the epithelium that contains almost no collagen, the lamina propria that is composed of abundant collagen, and the vocalis muscle layer. It is clinically important to visualize the tissue microstructure using a non-invasive method, especially in the case of vocal cord nodules or cancer, since histological changes in each layer of the vocal cord cause changes in the voice. Polarization-sensitive optical coherence tomography (PS-OCT) enables phase retardation measurement to evaluate birefringence of tissue with varied organization of collagen fibers in different tissue layers. Therefore, PS-OCT can visualize structural changes between normal and abnormal vocal cord tissue.
A rabbit laryngeal tumor model with different stages of tumor progression was investigated ex-vivo by PS-OCT. A phase retardation slope-based analysis, which quantifies the birefringence in different layers, was conducted to distinguish the epithelium, lamina propria, and muscle layers.
The PS-OCT images showed a gradual decrease in birefringence from normal tissue to advanced tumor tissue. The quantitative analysis provided a more detailed comparison among different stages of the rabbit laryngeal tumor model, which was validated by the corresponding histological findings.
Differences in tissue birefringence was evaluated by PS-OCT phase retardation measurement. It is also possible to indirectly infer the dysplastic changes based on the mucosal and submucosal alterations.
声带组织从表面到深部依次分为 3 个解剖学层次：上皮层几乎不含胶原，固有层富含胶原，以及声带肌层。临床上，使用非侵入性方法可视化组织微观结构非常重要，特别是在声带小结或癌症的情况下，因为声带各层的组织学变化会导致声音发生变化。偏振敏感光相干断层扫描（PS-OCT）能够通过相位延迟测量来评估具有不同胶原纤维组织排列的组织的双折射。因此，PS-OCT 可以可视化正常和异常声带组织之间的结构变化。
通过 PS-OCT 对具有不同肿瘤进展阶段的兔喉肿瘤模型进行了离体研究。基于相位延迟斜率的分析可定量评估不同组织层的双折射，从而区分上皮层、固有层和肌肉层。
PS-OCT 图像显示，从正常组织到晚期肿瘤组织，双折射逐渐降低。定量分析提供了兔喉肿瘤模型不同阶段之间的更详细比较，该比较得到了相应的组织学发现的验证。
通过 PS-OCT 相位延迟测量评估组织双折射的差异，也可以根据黏膜和黏膜下改变间接推断发育不良变化。
