Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications and Systems Engi, Japan.
Ministry of Fisheries and Livestock, Government of Bangladesh, Department of Livestock Services, Dha, Bangladesh.
J Biomed Opt. 2019 Jan;24(3):1-11. doi: 10.1117/1.JBO.24.3.031020.
We investigate a multispectral imaging method to evaluate spatiotemporal changes in both cutaneous hemoglobin concentration and light scattering parameter in mouse skin through diffuse reflectance spectroscopy using the reflectance images acquired at isosbestic wavelengths of hemoglobin (420, 450, 500, and 585 nm). In the proposed approach, Monte Carlo simulation-based empirical formulas are introduced to extract the scattering power b representing the wavelength dependence of light scattering spectrum of skin tissue, as well as the total hemoglobin concentration Cth in dermal vasculatures. The use of isosbestic wavelengths of hemoglobin enables the values of Cth and b to be estimated independently of the oxygenation of hemoglobin. Experiments using in vivo mice two-stage chemical carcinogenesis model are performed to confirm the feasibility of the proposed method for evaluating the changes in cutaneous vasculatures and tissue morphology during tumor initiation, promotion, and progression processes. The experimental results reveal that the changes in scattering power b of back skin are significantly reduced and followed by the increase in total hemoglobin concentration Cth in the carcinogenesis mice group, which indicates morphological changes in skin tissue such as edema and cell swelling caused by tumor promotion and successive angiogenesis along with tumor progression. The results suggest that the potential of the present method to detect cutaneous carcinogenesis in an early stage and monitor physiological changes during promotion and progression process of nonmelanoma tumors.
我们研究了一种多光谱成像方法，通过在等色波长（血红蛋白的 420、450、500 和 585nm）处获取的反射率图像，利用漫反射光谱来评估小鼠皮肤中血红蛋白浓度和光散射参数的时空变化。在提出的方法中，引入了基于蒙特卡罗模拟的经验公式，以提取散射功率 b，它代表皮肤组织光散射光谱的波长依赖性，以及真皮脉管系统中的总血红蛋白浓度 Cth。血红蛋白的等色波长的使用使得 Cth 和 b 的值可以独立于血红蛋白的氧合状态进行估计。使用体内小鼠两阶段化学致癌模型进行实验，以确认该方法评估肿瘤起始、促进和进展过程中皮肤脉管系统和组织形态变化的可行性。实验结果表明，背部皮肤散射功率 b 的变化明显降低，随后在致癌小鼠组中总血红蛋白浓度 Cth 增加，这表明皮肤组织的形态变化，如肿瘤促进和随后的血管生成以及肿瘤进展引起的水肿和细胞肿胀。结果表明，该方法具有在早期检测皮肤癌变并监测非黑色素瘤肿瘤促进和进展过程中生理变化的潜力。
