Frontiers in Nuclear Magnetic Resonance and Magnetic Particle Imaging

这项提案要求支持将探索与在极低磁场中进行的核磁共振(核磁共振)实验有关的基本问题的研究，以及与一种称为磁粒子成像(MPI)的非常新的成像方式有关的机会。核磁共振是一项非常成熟的实验技术，它使用磁场来探测原子核。它在科学、工程和医学中有许多应用，并构成了磁共振成像(MRI)的基础。MPI在某些方面类似于MRI。它也利用磁场，但它不是探测原子核，而是能够检测并快速绘制出非常小的生物兼容磁性粒子的分布。这些微粒非常小，可以作为示踪剂注射到血液中，为研究人员希望成为心血管成像的强大方法打开了大门。 提出了三条截然不同但相辅相成的调查路线。研究人员将使用甚低场(VLF)核磁共振来研究原子之间的复杂磁相互作用，首先用激光对原子进行极化，以便它们的原子核最终在同一方向上排列。这将导致混乱的行为，并将模仿人们知之甚少的过程，这可能会限制未来一代核磁共振光谱仪的分辨率。研究人员还将利用他们在甚低频核磁共振和核磁共振仪器设计方面的专业知识，帮助推进新兴的和密切相关的MPI领域。为此，他们已经构建了一个可以为微小物体成像的MPI系统原型；他们现在将专注于从提高灵敏度和图像质量到理解和规避可能限制构建人类规模成像系统的因素等一系列问题。最后，该提案将支持该小组继续和长期的努力，开发和完善甚低频核磁共振和核磁共振的工具、技术和应用程序。

This proposal requests support for research that will explore fundamental questions related to Nuclear Magnetic Resonance (NMR) experiments conducted in very-low magnetic fields and opportunities related to a very new imaging modality, called Magnetic Particle Imaging (MPI). NMR is a very-well established experimental technique that uses magnetic fields to probe the nuclei of atoms. It has many applications in science, engineering, and medicine, and forms the basis for Magnetic Resonance Imaging (MRI). MPI is in some respects similar to MRI. It also makes use of magnetic fields; but instead of probing nuclei, it is able to detect and rapidly map out the distribution of very small biocompatible magnetic particles. These particles are so small that they can be injected into the bloodstream as tracers, opening the door to what researchers hope will become powerful method for cardiovascular imaging. Three distinct but complementary lines of inquiry are proposed. Researchers will use very-low field (VLF) NMR to study complex magnetic interactions between atoms after first polarizing them with lasers, so that their nuclei end up being aligned in the same direction. This will lead to chaotic behaviour and will mimic poorly-understood processes that could limit the resolution of future-generation NMR spectrometers. Researchers will also draw on their expertise in the design of apparatus for VLF NMR and MRI to help advance the emerging and closely-related field of MPI. To this end, they have already constructed a prototype MPI system that can image small objects; they will now focus on issues ranging from the enhancement of sensitivity and image quality to understanding and circumventing factors that might limit the construction of a human-scale imaging system. Finally, the proposal will support continuing and long-term efforts by this group to develop and refine tools, techniques, and applications for VLF NMR and MRI.