Water suppression with B0 field gradient homospoil pulses in high-resolution NMR spectroscopy.

abstract：PURPOSE:To demonstrate feasibility of exploiting the spatial distribution of off-resonance surrounding metallic implants for accelerating multispectral imaging techniques. THEORY AND METHODS:Multispectral imaging (MSI) techniques perform time-consuming independent three-dimensional acquisitions with varying radio freq...

journal_title：Magnetic resonance in medicine

authors： Smith MR,Artz NS,Koch KM,Samsonov A,Reeder SB

更新日期：2014-12-01 00:00:00

abstract：:The cytosol of intact human red blood cells was loaded with 28.1 +/- 3.4 mM of dysprosium DTPA-BMA using a hypoosmotic technique. When loaded cells were diluted with saline and control cells to give an average dysprosium concentration of 3.3 +/- 0.5 mM, the transverse relaxation rate constants R(*)(2) and R(2) increas...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Tao JZ,Kennan RP,Gore JC

更新日期：2001-05-01 00:00:00

abstract：:The fast spin-echo (FSE) sequence is frequently used as a fast data-readout technique in conjunction with other pulse sequence elements, such as in fluid-attenuated inversion-recovery (FLAIR) and double inversion-recovery (DIR) sequences. In order to implement those pulse sequences, an understanding is required of how...

journal_title：Magnetic resonance in medicine

authors： Meara SJ,Barker GJ

更新日期：2005-07-01 00:00:00

abstract：:The role of relative cerebral blood volume (rCBV) in the early response of blood oxygenation level-dependent (BOLD) signal following sensory stimulation was assessed. Magnetic resonance imaging (MRI) measurements of rCBV and BOLD signal as a function of time (t) were compared with relative cerebral blood flow (rCBF) o...

journal_title：Magnetic resonance in medicine

authors： Marota JJ,Ayata C,Moskowitz MA,Weisskoff RM,Rosen BR,Mandeville JB

更新日期：1999-02-01 00:00:00

abstract：:High-field (>or=3 T) cardiac MRI is challenged by inhomogeneities of both the static magnetic field (B(0)) and the transmit radiofrequency field (B(1)+). The inhomogeneous B fields not only demand improved shimming methods but also impede the correct determination of the zero-order terms, i.e., the local resonance fre...

journal_title：Magnetic resonance in medicine

authors： Schär M,Vonken EJ,Stuber M

更新日期：2010-02-01 00:00:00

abstract：:We describe a doubly tuned radiofrequency (RF) local coil probe designed specifically for performing in vivo image-localized spectroscopy. The probe was designed using principles developed in connection with the counter-rotating-current (CRC) and planar-pair loop gap resonators for magnetic resonance imaging (MRI). Th...

journal_title：Magnetic resonance in medicine

authors： Grist TM,Jesmanowicz A,Kneeland JB,Froncisz W,Hyde JS

更新日期：1988-03-01 00:00:00

abstract：:A new approach to spin-echo imaging is presented in which the 180 degrees RF pulse refocuses two or more spin-echoes at different positions in the readout period. When simultaneous echo refocusing (SER) is implemented using multiple 180 degrees pulses, an undesirable mixing of stimulated echoes and primary echoes from...

journal_title：Magnetic resonance in medicine

authors： Günther M,Feinberg DA

更新日期：2005-09-01 00:00:00

abstract：PURPOSE:This study evaluates biochemical imbalances in a rat model that reflects dysfunctional pathways in migraine. The high sensitivity and spectral dispersion available to 1 H MRS at 21.1 T expands metabolic profiling in this migraine model to include lactate (Lac), taurine (Tau), aspartate, and Gly-a mixture of gly...

journal_title：Magnetic resonance in medicine

authors： Abad N,Rosenberg JT,Roussel T,Grice DC,Harrington MG,Grant SC

更新日期：2018-03-01 00:00:00

abstract：:NMR relaxation times (T1 and T2) and the water content (WC) of in vitro rat lungs were measured during the course of endotoxin lung injury in rats. Measurements of normal lungs, untreated endotoxin-injured lungs, and endotoxin-injured lungs treated with methylprednisolone (MPSL) were compared. The untreated endotoxin ...

journal_title：Magnetic resonance in medicine

authors： Shioya S,Haida M,Tsuji C,Ono Y,Miyairi A,Fukuzaki M,Ohta Y,Yamabayashi H

更新日期：1990-08-01 00:00:00

abstract：PURPOSE:Establishing a framework to evaluate performances of prospective motion correction (PMC) MRI considering motion variability between MRI scans. METHODS:A framework was developed to obtain quantitative comparisons between different motion correction setups, considering that varying intrinsic motion patterns betw...

journal_title：Magnetic resonance in medicine

authors： Pannetier NA,Stavrinos T,Ng P,Herbst M,Zaitsev M,Young K,Matson G,Schuff N

更新日期：2016-02-01 00:00:00

abstract：PURPOSE:Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS:Mapping a signa...

journal_title：Magnetic resonance in medicine

authors： Holbrook AB,Ghanouni P,Santos JM,Dumoulin C,Medan Y,Pauly KB

更新日期：2014-02-01 00:00:00

abstract：PURPOSE:A purely experimental method for MRI-based transfer function (TF) determination is presented. A TF characterizes the potential for radiofrequency heating of a linear implant by relating the incident tangential electric field to a scattered electric field at its tip. We utilize the previously introduced transfer...

journal_title：Magnetic resonance in medicine

authors： Tokaya JP,Raaijmakers AJE,Luijten PR,Sbrizzi A,van den Berg CAT

更新日期：2020-03-01 00:00:00

abstract：:A method is presented for the detection of quadrupole splitting in tissue, where the spectral line splittings are typically unobservable. The method used is a study of the rate of rotation of the flip angle as a function of radiofrequency (rf) amplitude. Our results with samples of skeletal muscle and cat brain indica...

journal_title：Magnetic resonance in medicine

authors： Joseph PM,Summers RM

更新日期：1987-01-01 00:00:00

abstract：:Magnetic resonance (MR) diffusion imaging is a useful technique with which to increase our understanding of pathologic damage to the central nervous system. To fully quantitate diffusion and anisotropy in the spinal cord, as in other tissues, it is necessary to determine the diffusion tensor. If spinal cord diffusion ...

journal_title：Magnetic resonance in medicine

authors： Clark CA,Werring DJ,Miller DH

更新日期：2000-01-01 00:00:00

abstract：:Unusually high image contrast in vivo magnetic resonance imaging of the brain becomes observable at high magnetic fields when the blood oxygenation level is lowered. The cause of the contrast has been attributed to a magnetic susceptibility effect induced by paramagnetic deoxyhemoglobin in red cells. When the cylinder...

journal_title：Magnetic resonance in medicine

authors： Ogawa S,Lee TM

更新日期：1990-10-01 00:00:00

abstract：:TOMROP is a multiple readout single inversion-recovery sequence which may potentially allow the measurement of multi-exponential T1 recoveries in vivo by NMR imaging. It is shown that several important modifications must be made to this sequence to permit T1 to be measured accurately and reliably. With these modificat...

journal_title：Magnetic resonance in medicine

authors： Gowland PA,Leach MO

更新日期：1992-07-01 00:00:00

abstract：:Fluid-attenuated inversion recovery (FLAIR) images obtained during the administration of supplemental oxygen demonstrate a hyperintense signal within the cerebrospinal fluid (CSF) that is likely caused by T1 changes induced by paramagnetic molecular oxygen. Previous studies demonstrated a linear relationship between t...

journal_title：Magnetic resonance in medicine

authors： Zaharchuk G,Martin AJ,Rosenthal G,Manley GT,Dillon WP

更新日期：2005-07-01 00:00:00

abstract：PURPOSE:To assess the performance, in the presence of scanner instabilities, of three dynamic correction methods which integrate ∆B0 mapping into the chemical exchange saturation transfer (CEST) measurement and three established static ∆B0 -correction approaches. METHODS:A homogeneous phantom and five healthy voluntee...

journal_title：Magnetic resonance in medicine

authors： Poblador Rodriguez E,Moser P,Dymerska B,Robinson S,Schmitt B,van der Kouwe A,Gruber S,Trattnig S,Bogner W

更新日期：2019-08-01 00:00:00

abstract：:Hyperpolarized 129Xe has been used to obtain gas phase images of mouse lung in vivo, showing distinct ventilation variation as a function of the breathing cycle. Spectra of 129Xe in the thorax show complex structure in both the gas phase (-4 to 3 ppm) and tissue-dissolved (190-205 ppm) regions. The alveolar gas peak s...

journal_title：Magnetic resonance in medicine

authors： Wagshul ME,Button TM,Li HF,Liang Z,Springer CS,Zhong K,Wishnia A

更新日期：1996-08-01 00:00:00

abstract：:Prospective motion correction methods using an optical system, diffusion-weighted prospective acquisition correction, or a free induction decay navigator have recently been applied to correct for motion in diffusion tensor imaging. These methods have some limitations and drawbacks. This article describes a novel techn...

journal_title：Magnetic resonance in medicine

authors： Alhamud A,Tisdall MD,Hess AT,Hasan KM,Meintjes EM,van der Kouwe AJ

更新日期：2012-10-01 00:00:00

abstract：:A proton NMR relaxation and pulsed field gradient self-diffusion study of water in fibrin gels, plasma, and blood clots has been performed with special emphasis on the effect of the sol-gel and shrinkage transitions. Deuteron NMR in fibrin gels was also studied to supplement the proton data. It is shown that a measure...

journal_title：Magnetic resonance in medicine

authors： Blinc A,Lahajnar G,Blinc R,Zidansek A,Sepe A

更新日期：1990-04-01 00:00:00

abstract：PURPOSE:Spatio-temporal encoding (SPEN) experiments can deliver single-scan MR images without folding complications and with robustness to chemical shift and susceptibility artifacts. Further resolution improvements are shown to arise by relying on multiple receivers, to interpolate the sampled data along the low-bandw...

journal_title：Magnetic resonance in medicine

authors： Liberman G,Solomon E,Lustig M,Frydman L

更新日期：2018-02-01 00:00:00

abstract：PURPOSE:Conventional 31 P chemical shift imaging is time-consuming and yields only limited spatial resolution. The purpose of this study was to demonstrate feasibility of 31 P echo-planar spectroscopic imaging (EPSI) in vivo at 7T. METHODS:A 3D 31 P EPSI sequence with trapezoidal-shaped gradient pulses was implemented...

journal_title：Magnetic resonance in medicine

authors： Korzowski A,Bachert P

更新日期：2018-03-01 00:00:00

abstract：:Longitudinal and transverse relaxation rates for the 11B resonances in sodium borocaptate (BSH) at varying concentrations were measured in undiluted horse serum in a 4.7 Tesla field. The results could be fit by a model that assumes fast exchange of the BSH molecule between a free and a bound state, using values of 0.7...

journal_title：Magnetic resonance in medicine

authors： Bendel P,Frantz A,Zilberstein J,Kabalka GW,Salomon Y

更新日期：1998-03-01 00:00:00

abstract：:Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...

journal_title：Magnetic resonance in medicine

authors： Lin W,Paczynski RP,Celik A,Hsu CY,Powers WJ

更新日期：1998-12-01 00:00:00

abstract：:A method is described for the correction of geometric distortions occurring in echo planar images. The geometric distortions are caused in large part by static magnetic field inhomogeneities, leading to pixel shifts, particularly in the phase encode direction. By characterizing the field inhomogeneities from a field m...

journal_title：Magnetic resonance in medicine

authors： Jezzard P,Balaban RS

更新日期：1995-07-01 00:00:00

abstract：PURPOSE:Banding artifacts in images acquired by balanced steady-state free precession (bSSFP) remain a challenge in MRI as they considerably reduce image quality, and diagnostic value deteriorates accordingly. As the steady-state tolerates small shifts in frequency, it is possible to acquire frequency-modulated bSSFP. ...

journal_title：Magnetic resonance in medicine

authors： Slawig A,Wech T,Ratz V,Tran-Gia J,Neubauer H,Bley T,Köstler H

更新日期：2017-12-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 00:00:00

abstract：PURPOSE:To test the efficacy of 7T MRS for in vivo detection of 2-hydroxyglutarate (2HG) in brain tumors. METHODS:The subecho times of point-resolved spectroscopy (PRESS) were optimized at 7T with density-matrix simulations and phantom validation to improve the 2HG signal selectivity with respect to the neighboring re...

journal_title：Magnetic resonance in medicine

authors： Ganji SK,An Z,Tiwari V,McNeil S,Pinho MC,Pan E,Mickey BE,Maher EA,Choi C

更新日期：2017-03-01 00:00:00

abstract：:In the pulsed arterial spin labeling (ASL) techniques EPISTAR, PICORE, and FAIR, subtraction of two images in which inflowing blood is first tagged and then not tagged yields a qualitative map of perfusion. An important reason this map is not quantitative is that there is a spatially varying delay in the transit of bl...

journal_title：Magnetic resonance in medicine

authors： Wong EC,Buxton RB,Frank LR

更新日期：1998-05-01 00:00:00