Non-resonance Electron Spin Imaging

项目总结/摘要 传统的磁共振成像方法，如MRI，使用射频（RF）波来操纵 自旋，亚原子粒子的量子力学性质。这些粒子包括各种类型的原子核 实验中使用恒定磁场，其强度必须与RF匹配， 观察共振现象。自旋是其局部分子环境的非常敏感的报告者。 它们可以报告周围分子的浓度、动力学和相互作用。但 当前的谐振方法具有其局限性，这些局限性源于无线电波的使用。当RF传播时 通过采样，只有无限小的功率量对可观测信号有贡献。大部分 能量被成像物体吸收。射频能量以热量形式消散。与此相关的是， 功率的使用是多个问题，如样品加热，有限的穿透深度，信号的功率饱和 放大器、自旋系统饱和（使数据失真）和噪声增加。这些问题对以下方面尤其重要： 电子顺磁共振成像传统EPR的替代方案，无RF非谐振 提出了电子自旋成像（NESI）方法。这项技术克服了与 使用RF功率。NESI背后的关键概念相对简单。在传统的方法中，RF用于 使自旋磁化相对于恒定磁场旋转。在NESI中，磁场随着 相对于磁化矢量。两个实验都测量了磁化矢量的进动 围绕着恒定的磁场提出了几种创新的数学和工程解决方案， 将上述概念转换成全功能成像系统。NESI仪器将在 并使用具有预定几何形状的各种样品（模型）进行严格测试。几倍 与标准EPR成像方法相比， 使用检测方法。量子感测的最新发展承诺了前所未有的灵敏度， 电子自旋信号的检测。这些新技术与传统的EPR是不兼容的。 几种标准类型的自旋探针将用于成像氧分压（pO 2）和酸度（pH） 分布在这些幻影中。在未来的研究中，NESI将用于临床前和临床研究。成像 生物打印组织和器官模型中的化学微环境是本发明的另一个重要应用。 技术.

Project Summary /Abstract Traditional magnetic resonance imaging methods, such as MRI, use radiofrequency (RF) waves to manipulate the spin, a quantum-mechanical property of subatomic particles. These particles include various types of nuclei and the electron. Constant magnetic fields are used in experiments, the strength of which must match the RF to observe resonance phenomena. The spins are very sensitive reporters of their local molecular environment. They can report the concentration, dynamics, and interactions of the surrounding molecules. However, the current resonance approach has its limitations that stem from the use of radio waves. When RF propagates through the sample, only an infinitesimally small amount of power contributes to the observable signals. Most of the energy is absorbed by the imaged object. RF energy dissipates as heat. Associated with this very inefficient use of power are multiple problems such as sample heating, limited penetration depth, power saturation of signal amplifiers, spin system saturation (distorts data), and increased noise. These problems are especially critical for electron-based paramagnetic resonance imaging. An alternative to traditional EPR, RF-free non-resonance electron spin imaging (NESI) method is proposed. This technology overcomes the limitations associated with the use of RF power. The key concept behind NESI is relatively simple. In the traditional methods, RF is used to rotate spin magnetization relative to the constant magnetic field. In NESI, the magnetic field is rotated with respect to the magnetization vector. Both experiments measure the precession of the magnetization vector around the constant magnetic field. Several innovative mathematical and engineering solutions are proposed to transform the described above concept into a fully functional imaging system. The NESI instrument will be built and rigorously tested using a wide range of samples (phantoms) with pre-determined geometry. A several-fold increase in sensitivity is expected compared to the standard EPR imaging method when traditional classical detection methods are used. Recent developments of quantum sensing promise unprecedented sensitivity for the detection of electron spin signals. These novel technologies are incompatible with the traditional EPR. Several standard types of spin probes will be used to image oxygen partial pressure (pO2) and acidity (pH) distribution in these phantoms. In future studies, NESI will be used in pre-clinical and clinical studies. Imaging of chemical microenvironment in bio-printed tissue and organ models is another important application of this technology.