About this Research Topic
Nuclear magnetic resonance (NMR) emerged in 1940s as one of many processes studied in the discipline of physics. Early efforts in NMR included theoretical and experimental aspects of relaxation and diffusion. The design and optimization of the apparatus of NMR thrived on the border of experimental physics and electrical engineering. Chemists soon adopted NMR spectroscopy to study molecular structures that initiated an ever-growing database of NMR spectra and corresponding molecules as their sources. A significant turning point is often regarded as the discovery of spatial encoding methods that formed pictures inside an object or a small animal, ushering in the era of magnetic resonance imaging (MRI). The prospect of performing MRI on a person called for larger and faster MRI devices that created new challenges for physicists and engineers. Subsequent applications created by human MRI were focused on physiology and medicine. Today, MRI is a major component of radiology.
The birth and early development of NMR and MRI can be viewed as an excellent example of interdisciplinary science and technology. Since then, the significance of performing MRI for medical purposes facilitated many following areas to have developed quite rapidly. Parallel imaging, as another milestone in MRI, demonstrated this path. Various aspects of parallel imaging in physics, engineering and computer science took research communities by storm for a few years and prompted vendors to release mature products soon after. It quickly became an integral and often invisible component in MRI. Nowadays, when MRI is performed at a clinical strength of 1.5 Tesla or 3 Tesla, it is often carried out with a dedicated RF coil for a specific anatomical region. The acquired data is reconstructed by pre-installed programs automatically. The contemporary workflow of MRI research is often limited to interpreting and correlating MRI results with other biomedical metrics. In other words, the interdisciplinary and innovative nature of MRI has somewhat faded in recent years.
Soon after 3 Tesla was approved as the ‘high-field’ for clinical MRI, the phrase ‘ultra high field’ (UHF) was adopted for research activities at 4.7 Tesla, 7 Tesla and above. As of 2015, 56 installations of 7 Tesla human scanners worldwide are serving as a premier platform for a new array of interdisciplinary research. Electrical engineers are designing novel RF and shim coils aimed to overcome pronounced field inhomogeneities at UHF. Physics and computer engineering together form a numerical framework for optimizing RF waveforms and simulating their effects in tissues. The benefits of UHF will be centered on improving spatial details of quintessential MRI metrics such as structure, diffusion and hemodynamic response. In addition, UHF allows more molecules to be detected in a crowed spectrum (i.e. 1H). For nuclei of lower abundance or sensitivity (i.e. 13C, 23Na, 31P), UHF provides higher signal-to-noise ratio for reliable detection. These measurements, many of which are impractical or impossible at 3T, can provide new insights in biochemistry and medicine. This Frontiers Research Topic is dedicated to research efforts on in vivo magnetic resonance at ultra-high field.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.