IEEE Trans Biomed Eng. 2023 Feb;70(2):671-680. doi: 10.1109/TBME.2022.3200626.
We have developed a single-sided magnet system that allows Magnetic Resonance relaxation and diffusion parameters to be measured.
A single-sided magnet system has been developed, using an array of permanent magnets. The magnet positions are optimised to produce a B magnetic field with a spot that is relatively homogenous and can project into a sample. NMR relaxometry experiments are used to measure quantitative parameters such as T, T and apparent diffusion coefficient (ADC) on samples on the benchtop. To explore preclinical application, we test whether it can detect changes during acute global cerebral hypoxia in an ovine model.
The magnet produces a 0.2 T field projected into the sample. Measurements of benchtop samples show that it can measure T, T and ADC, producing trends and values that are in line with literature measurements. In-vivo studies show a decrease in T during cerebral hypoxia that recovers following normoxia.
The single-sided MR system has the potential to allow non-invasive measurements of the brain. We also demonstrate that it can operate in a pre-clinical environment, allowing T to be monitored during brain tissue hypoxia.
MRI is a powerful technique for non-invasive diagnosis in the brain, but its application has been limited by the requirements for magnetic field strength and homogeneity that imaging methods have. The technology described in this study provides a portable alternative to acquiring clinically significant MR parameters without the need for traditional imaging equipment.
我们开发了一种单面磁体系统，可用于测量磁共振弛豫和扩散参数。
我们开发了一种单面磁体系统，使用了一组永磁体。优化了磁铁的位置，以产生具有相对均匀的光斑的 B 磁场，并且可以将光斑投射到样品中。NMR 弛豫测量实验用于测量台式样品上的定量参数，如 T1、T2 和表观扩散系数（ADC）。为了探索临床前应用，我们测试了它是否可以在绵羊模型的急性全脑缺氧期间检测到变化。
该磁体产生了一个 0.2 T 的磁场，投射到样品中。对台式样品的测量表明，它可以测量 T1、T2 和 ADC，并产生与文献测量值一致的趋势和值。体内研究表明，在脑缺氧期间 T1 降低，在正常氧合后恢复。
单面 MR 系统有可能允许对大脑进行非侵入性测量。我们还证明它可以在临床前环境中运行，允许在脑组织缺氧期间监测 T1。
MRI 是一种强大的脑部非侵入性诊断技术，但由于成像方法对磁场强度和均匀性的要求，其应用受到限制。本研究中描述的技术提供了一种无需传统成像设备即可获取临床重要 MR 参数的便携式替代方案。
