Variable-Field Nuclear Magnetic Relaxometer

项目摘要/摘要 麻省理工学院成像创新研究所(I3)要求使用核磁弛豫测量仪器 0.00023T至3.0T之间的野外自行车能力。弛豫计是一种测量原子核的装置 样品的磁弛豫时间(t1，t2)作为外加磁场的函数。弛豫测量法 在给定场强下进行的测量用于筛选功效小分子和 用于磁共振成像(MRI)的高分子探针。弛豫测量 作为变化的场和/或温度的函数来表征分子机制 支持核磁弛豫增强，从而指导分子策略来优化探针。 弛豫计量学也可以用来研究生物分子和顺磁离子之间的相互作用，以 表征和量化组织中分子水平的病理变化，或更好地了解生理 血液或组织的波动可能会影响核磁共振扫描的信号。 目前，麻省理工学院没有可以正常工作的弛豫计。直到最近，MGH的研究人员还在筛选其疗效 使用0.47T和1.4T的两个固定场弛豫计中的一个来研究新开发的弛豫剂。 然而，这两种仪器都已有20多年的历史，不再运行。弛豫测量 偶尔可以使用MGH Martinos中心的MRI扫描仪进行检查，但扫描仪的工作量很大 预订了影像研究，研究人员使用临床和非临床研究的费用分别为每小时655美元和300美元 扫描仪和当前的实验配置不能很好地控制样品温度。测量结果 有时也可以使用用于核磁共振光谱分析的11.7T或14.1T垂直钻孔磁体进行测试 在查尔斯敦海军造船厂。这些光谱仪可以进行可变温度记录，但这些 与临床磁共振扫描仪和绝大多数非临床磁共振扫描仪相比，光谱仪在非常高的磁场下运行 磁共振扫描仪，从而降低了为筛选磁共振成像探头效能而进行的测量的相关性。 所要求的仪器将(1)取代严重依赖的0.47T和1.4T弛豫计 以筛选新的磁共振成像探针，以及(2)提供独特且极其强大的实验资源 可以用来询问控制核磁弛豫的分子机制，引导成像 生物系统中生物分子的探针优化、结构、动力学和形态形成，以 促进幻影工程，以测试并行开发的新MRI扫描仪技术，以开发 生理变化(氧分压、红细胞压积)和磁共振成像探针如何影响人体功能磁共振成像的定量模型 信号，并指导成像生物标志物的识别。

Project Summary/ Abstract The MGH Institute for Innovation in Imaging (i3) requests nuclear magnetic relaxometry instrumentation with field cycling capabilities between 0.00023T and 3.0T. A relaxometer is a device that measures the nuclear magnetic relaxation times (T1, T2) of samples as a function of applied magnetic field. Relaxometry measurements performed at a given field strength are used to screen the efficacy small molecule and macromolecule probes that are used in magnetic resonance imaging (MRI). Relaxometry measurements performed as a function of varied field and/ or temperature us to characterize the molecular mechanisms that underpin nuclear magnetic relaxation enhancement and thus guide molecular strategies to probe optimization. Relaxometry can also be used to interrogate interactions between biomolecules and paramagnetic ions, to characterize and quantify molecular level pathologic changes in tissue, or to better understand how physiological fluctuations in blood or tissue may influence signal in an MRI scan. There is currently no functioning relaxometer at MGH. Until recently, MGH researchers screened the efficacy of newly developed relaxation agents using one of two fixed-field relaxometers functioning at 0.47T and 1.4T. However, both instruments are over 20 years old and are no longer operational. Relaxometry measurements can occasionally be performed using MRI scanners at the MGH Martinos Center, but the scanners are heavily booked for imaging studies, researchers are billed $655 and $300 per hour for the use of clinical and non-clinical scanners, and current experimental configuration provide poor control over sample temperature. Measurements can also occasionally be performed using the 11.7T or 14.1T vertical bore magnets used for NMR spectroscopy in the Charlestown Navy Yard. These spectrometers enable variable temperature recordings but these spectrometers operate at very high field compared to clinical MR scanners and the vast majority of non-clinical MR scanners, thus diminishing the relevance of measurements performed to screen MR imaging probe efficacy. The requested instrumentation will (1) replace the 0.47T and 1.4T relaxometers that have been heavily relied upon to screen new MR imaging probes, and (2) provide a unique and extremely powerful experimental resource that can be applied to interrogate molecular mechanisms that govern nuclear magnetic relaxation, guide imaging probe optimization, interrogate structure, dynamics, and speciation of biomolecules in biological systems, to facilitate engineering of phantoms to test on new MRI scanner technology being developed in parallel, to develop quantitative models of how physiologic changes (pO2, hematocrit) and MR imaging probes impact human fMRI signals, and to guide identification of imaging biomarkers.