Optical spectroscopy and imaging of tissue in magnetic fields

光在组织中的许多生物医学应用包括同时使用磁场。从基本物理原理和实验观察可知，强磁场会改变生物材料和组织的分子和结构特性。这些结构和分子的变化也会导致组织、荧光团和造影剂的光学性质的变化。 这一建议为研究磁场对生物组织光学特性的影响提供了支持。这些研究将包括评估磁场对组织的吸收、散射和荧光特性的影响，对各种光偏振态的组织去极化作用的影响，对造影剂和分子探针的荧光特性的影响，以及对人体和小动物模型血流的影响。我还计划探索核磁共振在生物材料和组织中的光学检测的可行性。由于现在可以在高达20 T的磁场中同时对生物材料和组织进行光学和MRS/MRI测量，因此研究尽可能广泛的磁场强度非常重要。该研究计划有望在生物医学光学技术领域取得重大进展。特别地，如果磁场的施加改善偏振光进入组织的穿透深度和/或增加偏振信噪比，则很可能导致非侵入性体内葡萄糖测量的问题的长期希望的解决方案。拟议的研究也可以导致在开发的组织表征，如光学MRI和/或MRS的磁光方法。磁场对组织和生物材料的影响的光学表现的研究也将有助于更好地了解磁场的生物效应，这是非常重要的，因为广泛的生物医学用途的MRI和MRS。

Many biomedical applications of light in tissues include simultaneous use of magnetic fields. From fundamental physical principles and experimental observations it is known that strong magnetic fields alter molecular and structural properties of biological materials and tissues. These structural and molecular changes should also result in changes of the optical properties of tissues, fluorophores, and contrast agents. This proposal requests support for the studies of the influence of magnetic fields on the optical properties of biological tissues. These studies will include assessment of the effects of magnetic fields on the absorptive, scattering, and fluorescent characteristics of tissue, on the depolarizing action of tissue for various polarization states of light, on the fluorescent characteristics of contrast agents and molecular probes, and on the blood flow in humans and in small animal models. I also plan to explore the feasibility of the optical detection of the nuclear magnetic resonance in biological materials and tissues. Since simultaneous optical and MRS/MRI measurements in biomaterials and tissues are now becoming available in the fields up to 20T, it is important to investigate as broad range of magnetic field intensities as possible. The proposed research program is expected to result in a significant progress in biomedical optical techniques. In particular, if the application of the magnetic field improves the penetration depth of the polarized light into tissues and/or increases the polarimetric signal-to-noise ratio, it is likely to lead to a long hoped-for solution of the problem of the non-invasive in-vivo glucose measurements. The proposed studies can also result in the development of fundamentally new magneto-optical methods of tissue characterization, such as the optical MRI and/or MRS. Studies of the optical manifestations of the influence of magnetic fields on tissues and biomaterials will also contribute to a better understanding of the biological effects of magnetic fields, which is very important because of the wide biomedical uses of MRI and MRS.