Three dimensional mapping of turbid media by hyper spectral imaging

医学成像诊断中的非侵入性模式至关重要，以尽量减少患者的风险，特别是因为许多疾病需要重复成像。此外，为了防止高昂的费用妨碍定期检查，需要快速和具有成本效益的成像方式。理想情况下，这些方法还应该实现无标签成像，因为标签对患者有潜在的副作用，如过敏。此外，开发合适的标记物是一个昂贵且耗时的过程。高光谱成像系统具有实现快速、低成本、无创和无标签成像的潜力。因此，它们提供了克服上述所有挑战的机会。因此，计划研究项目的目标是编写和研究将高光谱图像转换为三维组织图像的方法。导致组织中穿透深度的波长依赖的两种机制将用于此：组织成分（如血红蛋白和水）的波长依赖吸收以及组织的波长依赖散射行为。在这个项目的范围内，研究和评估了不同的转换方法。因此，一种检查恶性近表面组织改变的光学非侵入性方式有望为医生提供更大的视野。与光学相干层析成像等现有的光学三维重建方法相比，该方法不仅可以测量和分析折射率和散射的变化，还可以测量和分析吸光率的变化。因此，吸收剂浓度的变化，如癌变组织和健康组织的血液量或散射浓度的变化，这意味着血管和周围组织中的散射体的数量，应该是可检测到的。散射和吸收体变化的可检测性与深度分辨图像的重建相结合，有望改善对恶性地下变化的检测。由于特定深度的图像不再与所有其他深度卷积，因此简化了检测。这将显著增加对比度，并使诊断更加可靠，因为可能的组织改变伪装被去除。此外，由于成像方法是无接触的，使用标准的白光光源照明，它将使低风险和廉价的重复检查患者。

Non-invasive modalities in medical imaging diagnostics are of vital importance in order to minimize the risks for patients, particularly since many diseases necessitate repetitive imaging. Furthermore, preventing high costs from impeding regular examinations, fast and cost-efficient imaging modalities are needed. Ideally, these methods should also enable label free imaging, as labels bear potential side effects for the patients such as allergies. Furthermore, the development of suitable markers is a costly and time-consuming process. Hyperspectral imaging systems have the potential to enable fast, low-cost, non-invasive and label free imaging. Thus, they provide the opportunity to overcome all the mentioned challenges. Therefore, the goal of the planned research project is to compile and to investigate methods for the transformation of hyperspectral images into three-dimensional tissue images. Two mechanisms leading to a wavelength dependency of the penetration depth in tissue will be used for this: the wavelength dependent absorption in tissue constituents such as hemoglobin and water as well the wavelength dependent scattering behavior of the tissue. Within the scope of this project different transformation approaches are investigated and evaluated. As outcome, an optical non-invasive modality for the examination of malign near-surface tissue alterations is expected which also provides the doctor with a large field of view.Compared to established optical 3D reconstruction methods such as Optical Coherence Tomography, the new approach has the advantage of not only measuring and analyzing changes in refractive index and scattering, but also changes in absorptivity. Therefore, absorber concentration changes, such as the amount of blood in cancerous and healthy tissue or scattering concentration changes, this means the amount of scatterers in blood vessel and surrounding tissue, should be detectable. This combination of the detectability of scattering and absorber alterations and the reconstruction of the in-depth resolved images promises improved detection of malign subsurface alterations. The detection is simplified by the fact that the images of a specific depth are not convoluted with all other depths anymore. This should increase the contrast significantly and it should enable a more reliable diagnosis since possible disguises of tissue alterations are removed. Furthermore, since the imaging approach is contact free and uses standard white light sources for illumination, it will enable low-risk and inexpensive repetitive examinations of patients.