Magnetic resonance: Back to the future

核磁共振是一种强大的研究工具，它基于对某些原子核发出的电磁信号的检测。这种方法非常类似于无线电的工作方式：原子是发射信号的无线电台，而研究人员反过来又是收听者，他们将收音机调到选定的电台。然而，核磁共振的特殊之处在于，来自原子的信号的频率与它们所在的当地环境唯一地联系在一起。因此，这些信号提供了有关各种物理、化学、生物和材料属性的非常精确的信息。例如，来自我们体内氢原子的核磁共振信号可以非侵入性地检测到，并用于定位和诊断损伤或疾病。这项技术被称为磁共振成像(MRI)，是现代医学中最重要的工具之一。核磁共振自20世纪50年代开始使用，核磁共振自20世纪70年代开始使用。自那时以来，这两种技术都取得了巨大的进步，创新在很大程度上是由“越大越好”的方法推动的，在这种方法中，使用了越来越强的磁场。任何做过核磁共振扫描的人都可以证明这个设备的大小，它实际上是一个巨大的圆柱形磁铁，为患者提供了一个中心孔。几乎所有的研究系统都采用同样的圆柱形磁铁设计，几十年来，“一刀切”的策略一直主导着核磁共振/核磁共振技术。然而，有许多充分的理由既要逆势而行，又要探索新的特定于应用程序的设计，为更广泛的用户提供更好的功能。一个例子是在较低磁场下运行的更轻、更便宜的核磁共振扫描仪的潜力。它们可能不像大型临床扫描仪那样产生高质量的图像，但它们可以是便携的，可以为特定情况提供出色的护理点成像，或者用于无法使用MRI技术的小型或偏远社区。在许多方面，这种方法就像回到了磁共振在低得多的磁场和简单得多的设备上进行的时候。然而，与早期的核磁共振/核磁共振相比，情况发生了很大变化，这一次，围绕新技术和更广泛的潜在应用，将推动一个创新时代，而不会走上越大越好、一刀切的老路。因此，磁共振的未来可能只是“更小、更轻、更智能”。我的研究计划的目标是促进磁共振技术的性能和广泛应用。我将专注于低场核磁共振/核磁共振新的专用硬件和技术的开发，特别是一种被称为无梯度成像的方法，该方法使其本身具有更多功能的设备。潜在的应用范围从医疗保健(例如，医疗现场医学成像)到农业(例如，评估谷物质量)。

Nuclear magnetic resonance (NMR) is a powerful research tool based on the detection of electromagnetic signals that emanate from the nuclei of certain atoms. The method is quite analogous to the way radio works: the atoms are the radio stations emitting signals, while the researcher, in turn, is the listener who tunes their radio to the station of choice. What is so special about NMR, however, is that the frequency of the signals coming from the atoms are uniquely linked to the local environment in which they are situated. As such, these signals provide very precise information about a wide variety of physical, chemical, biological, and material properties. For example, the NMR signal from the hydrogen atoms in our bodies can be detected non-invasively and used to locate and diagnose injury or disease. This technique, known as magnetic resonance imaging (MRI), is one of the most important tools in modern medicine. NMR has been in use since the 1950s, and MRI since the 1970s. Both techniques have advanced immensely since those times, with innovation largely being driven by a "bigger-is-better" approach, in which stronger and stronger magnetic fields have been employed. Anyone who has ever had an MRI scan can attest to the size of the apparatus, which is in fact a large cylindrical magnet with a central bore for the patient. This same cylindrical magnet design is used for almost all research systems as well, and a "one-style-fits-all" strategy has dominated NMR/MRI for decades. There are many good reasons to buck both these trends, however, and to explore new application-specific designs that offer greater functionality to a broader range of users. One example is the potential for lighter, cheaper MRI scanners operating at lower magnetic field. They may not produce as high a quality image as large clinical scanners, but they could be portable and provide excellent point-of-care imaging for specific situations, or be used in small or remote communities where MRI technology is otherwise unavailable. In many ways, this approach is like going way back in time to when magnetic resonance was performed in much lower fields and with much simpler apparatus. Much has changed since the early days of NMR/MRI, however, and this time around new technology and a broader range of potential applications will fuel an era of innovation that will not end up on the old path of bigger-is-better and one-style-fits-all. As a result, the future of magnetic resonance might just be "smaller, lighter, and smarter." The goal of my research program is to advance the performance and widespread use of magnetic resonance technology. I will focus on the development of new application-specific hardware and techniques for low-field NMR/MRI, in particular a method known as gradient-free imaging, which lends itself to more versatile apparatus. Potential applications range from health care (e.g. point-of-care medical imaging) to agriculture (e.g. evaluating grain quality).