
doi: 10.1002/mrm.22188
pmid: 19918899
AbstractConventionally, MR images are formed by applying gradients to the main static magnetic field (B0). However, the B0 gradient equipment is expensive, power‐hungry, complex, and noisy and can induce eddy currents in nearby conducting structures, including the patient. Here, we describe a new silent, B0 gradient‐free MRI principle, Transmit Array Spatial Encoding (TRASE), based on phase gradients of the radio‐frequency (RF) field. RF phase gradients offer a new method of k‐space traversal. Echo trains using at least two different RF phase gradients allow spin phase to accumulate, causing k‐space traversal. Two such RF fields provide one‐dimensional imaging and three are sufficient for two‐dimensional imaging. Since TRASE is a k‐space method, analogues of many conventional pulse sequences are possible. Experimental results demonstrate one‐dimensional and two‐dimensional RF MRI and slice selection using a single‐channel, transmit/receive, 0.2 T, permanent magnet, human MR system. The experimentally demonstrated spatial resolution is much higher than that provided by RF receive coil array sensitivity encoding alone but lower than generally achievable with B0 gradients. Potential applications are those in which one or more of the features of simplified equipment, lower costs, silent MRI, or the different physics of the image formation process are particularly advantageous. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
low field, Phantoms, Imaging, Radio Waves, Reproducibility of Results, Image Enhancement, Magnetic Resonance Imaging, Sensitivity and Specificity, RF phase gradient, Magnetics, radiofrequency, Image Interpretation, Computer-Assisted, TRASE, Humans, Algorithms, MRI
low field, Phantoms, Imaging, Radio Waves, Reproducibility of Results, Image Enhancement, Magnetic Resonance Imaging, Sensitivity and Specificity, RF phase gradient, Magnetics, radiofrequency, Image Interpretation, Computer-Assisted, TRASE, Humans, Algorithms, MRI
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 58 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
