Non-resonance Electron Spin Imaging

项目摘要/摘要 传统的磁共振成像方法，如磁共振成像，使用射频(RF)波进行操作 自旋，一种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。 和电子。在实验中使用恒定磁场，其强度必须与射频匹配 观察共振现象。自旋是当地分子环境的非常敏感的记者。 它们可以报告周围分子的浓度、动力学和相互作用。然而， 目前的共振方法有其局限性，这源于无线电波的使用。当射频传播时 通过样本，只有极少量的功率对可观察到的信号做出贡献。大部分 能量被成像的物体吸收。射频能量以热量的形式消散。与此相关的是非常低效的 功率的使用存在样品加热、穿透深度受限、信号功率饱和等多重问题 放大器、自旋系统饱和(扭曲数据)和增加的噪声。这些问题对于 基于电子的顺磁共振成像。传统EPR的替代方案--无射频非共振 提出了电子自旋成像(NESI)方法。这项技术克服了与 射频功率的使用。NESI背后的关键概念相对简单。在传统方法中，射频被用来 相对于恒定磁场旋转自旋磁化强度。在NESI中，磁场随时间旋转 与磁化向量有关。这两个实验都测量了磁化矢量的进动 围绕着恒定磁场。提出了几种创新的数学和工程解决方案，以 将上述概念转化为功能齐全的成像系统。NESI仪器将建成 并使用具有预定几何形状的广泛样本(模体)进行了严格的测试。几倍于 与传统的经典EPR成像方法相比，灵敏度有望提高 使用了检测方法。量子传感的最新发展预示着对 电子自旋信号的检测。这些新技术与传统的EPR不兼容。 几种标准类型的自旋探针将被用来成像氧分压(PO2)和酸度(PH) 在这些幻影中的分布。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该方法的另一个重要应用 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.