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性质。这些结构和分子的变化也应该导致组织、荧光团和造影剂的光学性质的变化。因此，这项提议要求支持磁场对生物组织光学性质的影响的研究。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，对组织对不同偏振状态光的去极化作用的影响，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。我还计划探索生物材料和组织中核磁共振的光学检测的可行性。由于生物材料和组织中的同时光学和MRS/MRI测量现在可以在20T以下的领域使用，因此研究尽可能广泛的磁场强度是很重要的。拟议的研究计划有望导致生物医学光学技术的重大进步。特别是，如果磁场的应用改善了偏振光对组织的穿透深度和/或提高了偏振信噪比，很可能导致人们期待已久的无创体内血糖测量问题的解决。所提出的研究还可以导致开发新的组织表征的磁光方法，例如光学MRI和/或MRS。研究磁场对组织和生物材料的影响的光学表现也将有助于更好地理解磁场的生物效应，这是非常重要的，因为MRI和MRS在生物医学上的广泛应用。

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.