NMR photography has gained significant attention as a method of storing and retrieving information using NMR spectroscopy. Among the commonly practiced methods the most important is the frequency encoding by use of a multi-frequency pulse on a liquid crystal molecule. We propose and demonstrate another robust method which relies on spatial encoding. Spatial information is mapped onto the spectr...

In gradient echo (GRE) imaging, three compartment water modeling (myelin water, axonal water and extracellular water) in white matter has been demonstrated to show different frequency shifts that depend on the relative orientation of fibers and the B0 field. This finding suggests that in GRE-based myelin water imaging, a signal model may need to incorporate frequency offset terms and become a c...

Large energy spread of muon beams can be reduced by so-called phase rotation. It requires rather low frequency or long slope in the RF waveform and rather high gradient field against the short muon lifetime. Because such a low frequency high gradient RF cavity is difficult to construct, a high frequency bunching system is proposed. The bunching system located after 100m from a production target...

Using simultaneous acquisition from multiple channels of a radio-frequency (RF) coil array, magnetic resonance inverse imaging (InI) achieves functional MRI acquisitions at a rate of 100ms per whole-brain volume. InI accelerates the scan by leaving out partition encoding steps and reconstructs images by solving under-determined inverse problems using RF coil sensitivity information. Hence, the ...

Technological activities to design, manufacture, and test new accelerating devices using different materials and methods is under way all over the world. The main goal of these studies is to increase the accelerating gradients and reduce the probability of radio-frequency (RF) breakdown. Indeed, it is still not clear why, by increasing the intensity of the applied field, intense surface damage ...

The density collapse was observed in the improved confinement mode sustained by the hot cathode biasing in Tohoku University Heliac (TU-Heliac). The density profiles showed the steep gradient around the core plasma region before the collapse. The steep density profile collapsed accompanied with the bursting high frequency fluctuation (100 < f < 500 kHz), which had m = 2 ~ 3 poloidal mode number...

RATIONALE AND OBJECTIVES Acoustic noise both in terms of its magnitude and frequency during magnetic resonance imaging (MRI) scan is influenced by imaging parameters and pulse sequences. It varies because of many different factors such as structure, materials, and magnetic field strength. The purpose of our study is to evaluate the characteristics of acoustic noise independent of MRI scan proto...

A method to reduce the acoustic noise generated by gradient systems in magnetic resonance imaging (MRI) is proposed based on the linear response theory. Since the acoustic frequency response function of typical gradient coils is low in the range below 200 Hz, the noise level can be significantly reduced by using gradient pulse sequences whose spectra are limited to this frequency range. Such "s...

ture to monitoring intravascular contrast agents or consent) , respectively, that have been acquired in the abvisualizing brain function. In particular, gradient-echo MRI sence and presence of macroscopic magnetic field gradients. sequences sensitized to alterations of cerebral blood oxygenThe images were obtained at 2.0 T (Siemens Magnetom ation (CBO) have resulted in exciting new tools for hi...

PURPOSE To investigate the quantitative impact of frequency drift on Gamma-Aminobutyric acid (GABA+)-edited MRS of the human brain at 3 Tesla (T). METHODS Three sequential GABA+-edited MEGA-PRESS acquisitions were acquired in fifteen sessions; in ten of these, MRS was preceded by functional MRI (fMRI) to induce frequency drift, which was estimated from the creatine resonance at 3.0 ppm. Simul...