Tabletop liquid-helium-free, persistent-mode 1.5-T/70-mm osteoporosis MRI magnet

桌面无液氦、持续模式 1.5-T/70-mm 骨质疏松 MRI 磁体

• 批准号: 9239606
• 负责人: Yukikazu Iwasa
• 金额: $ 66.64万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9239606
• 关键词: Adult; Age; American; Bone Density; Bone Matrix; Clinic; Coupled; Densitometry; Developing Countries; Development; Diagnosis; Disasters; Disease; Distal; Dual-Energy X-Ray Absorptiometry; Elements; Environment; Exposure to; Femoral Neck Fractures; Fingers; Generations; Goals; Hand; Helium; High temperature of physical object; Hip region structure; Hospitals; Hour; Image; Individual; Insurance Coverage; Ionizing radiation; Iron; Left; Liquid substance; Location; Magnesium; Magnetic Resonance Imaging; Measurement; Measures; Metabolic; Metabolic Bone Diseases; Minerals; Nitrogen; Osteoporosis; Pain; Patients; Peripheral; Phalanx; Primary Care Physician; Public Health; Recovery; Research; Research Infrastructure; Resolution; Resources; Risk; Scanning; Series; Shock; Site; Solid; Spinal Fractures; System; Technology; Temperature; Thick; Time; Weight; Wrist; X-Ray Computed Tomography; base; bone; bone fragility; bone loss; cold temperature; cost; cryogenics; density; design; economic impact; fracture risk; innovation; instrumentation; magnetic field; mineralization; mortality; novel; operation; osteoporosis with pathological fracture; programs; prototype; screening; solid state; statistics; superconductivity; tomography; tool; vibration

Less than half of at-risk Americans are screened for osteoporosis, a potentially debilitating age- associated disease in which metabolically-driven bone loss leads to fragile bones and increased risk of fracture. By imaging the trabecular network microarchitecture at high spatial resolution, and measuring the bone mineral and bone matrix content, (full 3D bone density, degree of mineralization, cortical thickness, histomorphometry statistics) MRI potentially can characterize bone to a far more complete degree than DXA, quantitative computed tomography (QCT), or even peripheral microcomputed tomography, with complete avoidance of exposure to ionizing radiation. MRI of course is generally a very expensive technology requiring extensive hospital real estate, infrastructure and support facilities. However, a novel superconducting magnet technology based on the high-temperature superconductor (HTS) magnesium diboride, MgB2, and solid nitrogen (SN2), promises a new generation of inexpensive MRI magnets which completely dispense with the use of liquid helium coolant that has recently undergone a series of supply and cost crises, threatening MRI scanners worldwide. In this project we develop a tabletop MgB2 MRI magnet prototype as a demonstration of this new magnet technology. The magnet, to be integrated into a phalangeal MRI scanner prototype, will be readily sited anywhere, and which could be used for universal screening for metabolic bone disease. The specific aims of this project are: 1) completion of a tabletop, persistent-mode, liquid- helium-free, cryocooled superconducting (MgB2) 1.5-T/70-mm bore MRI magnet prototype for phalangeal scanning for osteoporosis research; 2) demonstration, by Dr. Jerome Ackerman (Co-I) of the Martinos Center, MGH, of the potentially huge benefits of MgB2/SN2 technology for MR magnets in the context of a very compact affordable scanner—he will measure 3D bone mineral and matrix density and trabecular microstructure of the 5th distal phalanx of the left hand by solid-state MRI. The innovative magnet design concepts include the first-ever persistent-mode operation in high-temperature superconducting magnet and inclusion of solid nitrogen (SN2) in the cold chamber. These features result in: 1) a field strength and temporal stability respectively at least ~3 times greater and far better than that of a tabletop permanent magnet, because while this magnet operates in persistent-mode, permanent magnets are highly temperature sensitive; 2) persistent-mode magnet operation, nominally at 14 K, for a period of ~10 hours with the cryocooler off, provides a vibration-free environment for osteoporosis MRI measurement; and 3) the whole unit is compact enough to be placed on a table.

不到一半的高风险美国人因骨质疏松症而受到筛查，这可能使人衰弱 - 相关疾病，代谢驱动的骨质流失导致骨骼脆弱并增加 骨折的风险。通过在高空间分辨率下成像小梁网络微体系结构， 并测量骨矿物质和骨基质含量（完整的3D骨密度，程度，程度 矿化，皮质厚度，组织形态计量学统计）MRI可能表征 骨头比DXA更完整，定量计算机断层扫描（QCT）或 即使是外围微型计算断层扫描，完全避免了电离接触 辐射。当然，MRI通常是一项非常昂贵的技术，需要大量医院 房地产，基础设施和支持设施。但是，一种新颖的超导磁铁 基于高温超导体（HTS）Diboride的技术，MGB2， 和固体氮（SN2）有望有新一代廉价的MRI磁铁 完全分配使用最近经历过一系列的液态氦冷却剂 供应和成本危机，威胁全球MRI扫描仪。在这个项目中，我们开发了一个 桌面MGB2 MRI磁铁原型作为这种新磁铁技术的演示。这 磁铁将被整合到指定的MRI扫描仪原型中，很容易被放置 任何地方，可以用于代谢骨病的普遍筛查。 该项目的具体目的是：1）完成桌面，持续模式，液体 - 无氦，冷冻的超导（MGB2）1.5-T/70毫米孔MRI磁铁原型 用于骨质疏松研究的指定扫描； 2）示威，作者：杰罗姆·阿克曼（Jerome Ackerman）博士 MGH马提尼斯中心（MGH）的（Co-1），这是MGB2/SN2技术的巨大好处 MR磁铁在非常紧凑的负担得起的扫描仪的背景下 - 他将测量3D骨头 矿物质和基质密度以及小梁的微观结构 固态MRI的左手。创新的磁铁设计概念包括有史 高温超导磁铁中的持续模式操作和固体包含 冷室中的氮（SN2）。这些功能导致：1）野外强度和临时性 稳定性分别比桌面永久性的稳定性至少大约3倍 磁铁，因为该磁铁以持久模式运行时，永久磁铁高度高 温度敏感； 2）名义上在14 K处的持续模式磁铁操作，持续一段时间 〜20小时与冷冻机关闭，为骨质疏松MRI提供了无振动的环境 测量; 3）整个单元足够紧凑，可以放在桌子上。