Low-Cost High-Performance MRI.
Low-Cost High-Performance MRI.
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DOI：
10.1038/srep15177
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发表时间：
2015-10-15
影响因子：
4.6
通讯作者：
Rosen MS
中科院分区：
文献类型：
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作者：
Sarracanie M;LaPierre CD;Salameh N;Waddington DEJ;Witzel T;Rosen MS
磁共振成像（MRI）在以高空间和时间分辨率非侵入性地可视化解剖结构和功能方面是无与伦比的。然而，为了克服弱极化核自旋的感应检测中固有的低灵敏度，绝大多数临床MRI扫描仪采用产生非常高的磁场的超导磁体。通常在1.5-3特斯拉（T），这些强大的磁铁是巨大的，并有非常严格的基础设施要求，排除在许多环境中的操作。MRI扫描仪的购买、放置和维护成本很高，每特斯拉（T）磁场的购买价格接近100万美元。在这里，我们提出了一个非常简单的，非低温的方法，高性能的人体MRI在超低磁场，现代欠采样策略相结合的完全重新聚焦动态自旋控制使用稳态自由进动技术。在6.5 mT（比临床MRI扫描仪低450倍以上）下，我们使用简单的开放几何电磁体在活体人脑中展示了（2.5 × 3.5 × 8.5）mm 3的成像分辨率，并在6分钟内采集了整个大脑的3D图像。我们认为，这些实用的超低磁场MRI（<10 mT）实现将补充传统的MRI，提供临床相关的图像，并为经济实惠（<50，000美元）和强大的便携式设备设定新的标准。
Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5–3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.