Phosphorus-31 magnetic resonance spectroscopy in humans by spectroscopic imaging: localized spectroscopy and metabolite imaging.

abstract：:Accelerated magnetic resonance imaging techniques reduce signal acquisition time by undersampling k-space. A fundamental problem in accelerated magnetic resonance imaging is the recovery of quality images from undersampled k-space data. Current state-of-the-art recovery algorithms exploit the spatial and temporal stru...

journal_title：Magnetic resonance in medicine

authors： Asif MS,Hamilton L,Brummer M,Romberg J

更新日期：2013-09-01 00:00:00

abstract：PURPOSE:To develop and demonstrate the feasibility of a new technique for respiratory-gated, fat-suppressed, three-dimensional spoiled gradient-recalled echo (3D-SPGR) with navigator gating for more accurate and robust motion detection. METHODS:A navigator-gated 3D-SPGR technique was modified to include a wait period ...

journal_title：Magnetic resonance in medicine

authors： Iwadate Y,Brau AC,Vasanawala SS,Kabasawa H

更新日期：2014-07-01 00:00:00

abstract：PURPOSE:To characterize the q-space truncation and sampling on the spin-displacement probability density function (PDF) in diffusion spectrum imaging (DSI). METHODS:DSI data were acquired using the MGH-USC connectome scanner (Gmax  = 300 mT/m) with bmax  = 30,000 s/mm2 , 17 × 17 × 17, 15 × 15 × 15 and 11 × 11 × 11 gri...

journal_title：Magnetic resonance in medicine

authors： Tian Q,Rokem A,Folkerth RD,Nummenmaa A,Fan Q,Edlow BL,McNab JA

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:To obviate online slice-by-slice RF shim optimization and reduce B1+ mapping requirements for patient-specific RF shimming in high-field magnetic resonance imaging. THEORY AND METHODS:RF Shim Prediction by Iteratively Projected Ridge Regression (PIPRR) predicts patient-specific, SAR-efficient RF shims with a m...

journal_title：Magnetic resonance in medicine

authors： Ianni JD,Cao Z,Grissom WA

更新日期：2018-11-01 00:00:00

abstract：:The recently developed technique of gradient, high-resolution magic-angle spinning NMR (g-hr-MAS-NMR) spectroscopy was applied to the study of ex vivo human lipoma and liposarcoma tissue. Compared with conventional 1H-NMR, the g-hr-MAS method yielded a large improvement in spectral resolution and permitted the detecti...

journal_title：Magnetic resonance in medicine

authors： Millis KK,Maas WE,Cory DG,Singer S

更新日期：1997-09-01 00:00:00

abstract：:Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high-field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in...

journal_title：Magnetic resonance in medicine

authors： Mao W,Smith MB,Collins CM

更新日期：2006-10-01 00:00:00

abstract：PURPOSE:Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. METHODS:Mice were inoculated orthotopically with human U87-EGFRvIII gliom...

journal_title：Magnetic resonance in medicine

authors： Xu X,Chan KW,Knutsson L,Artemov D,Xu J,Liu G,Kato Y,Lal B,Laterra J,McMahon MT,van Zijl PC

更新日期：2015-12-01 00:00:00

abstract：PURPOSE:We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathi...

journal_title：Magnetic resonance in medicine

authors： Kaushik SS,Robertson SH,Freeman MS,He M,Kelly KT,Roos JE,Rackley CR,Foster WM,McAdams HP,Driehuys B

更新日期：2016-04-01 00:00:00

abstract：:The success in utilizing in vivo NMR to identify and/or monitor metabolic abnormalities will be determined in large part on the reliability with which the spectral parameters of the metabolites present can be measured. For these reasons it is clear that there is a need for the development of algorithms with which to o...

journal_title：Magnetic resonance in medicine

authors： Lenkinski RE,Allman T,Scheiner JD,Deming SN

更新日期：1989-06-01 00:00:00

abstract：:This paper describes a method for correcting the chemical-shift artifacts in 19F NMR imaging of perfluoroctylbromide emulsion (PFOB) by utilizing the two spectral peaks of PFOB which have a long T2 value in conjunction with the Dixon method. Corrected images are obtained from the magnitude of the measured images using...

journal_title：Magnetic resonance in medicine

authors： Lee HK,Nalcioglu O,Buxton RB

更新日期：1992-02-01 00:00:00

abstract：:MR imaging experiments were conducted to investigate the feasibility of estimating vascular pulse pressure waveforms from measurements of blood flow rates and vessel cross-sectional area. Blood flow waveforms were measured in the aorta's of three 25-30-kg pigs at multiple imaging sections using phase-contrast velocity...

journal_title：Magnetic resonance in medicine

authors： Urchuk SN,Fremes SE,Plewes DB

更新日期：1997-08-01 00:00:00

abstract：:For clinical 31P MR spectroscopic imaging (MRSI) studies, where signal averaging is necessary, some improvement of sensitivity and spatial response function may be achieved by acquiring data over a spherical k-space volume and varying the number of averages acquired in proportion to the desired spatial filter. Eight d...

journal_title：Magnetic resonance in medicine

authors： Hugg JW,Maudsley AA,Weiner MW,Matson GB

更新日期：1996-09-01 00:00:00

abstract：:In spin echo imaging, magnetization is assigned to a location defined by its frequency of rotation. In the presence of a static magnetic field inhomogeneity, however, this location does not correspond to the true location of the magnetization. This paper describes a magnetic resonance imaging technique called phase co...

journal_title：Magnetic resonance in medicine

authors： Kim JK,Plewes DB,Henkelman RM

更新日期：1995-04-01 00:00:00

abstract：PURPOSE:To enable fast and flexible high-resolution four-dimensional (4D) MRI of periodic thoracic/abdominal motion for motion visualization or motion-corrected imaging. METHODS:We proposed a Cartesian three-dimensional k-space sampling scheme that acquires a random combination of k-space lines in the ky/kz plane. A p...

journal_title：Magnetic resonance in medicine

authors： Küstner T,Würslin C,Schwartz M,Martirosian P,Gatidis S,Brendle C,Seith F,Schick F,Schwenzer NF,Yang B,Schmidt H

更新日期：2017-08-01 00:00:00

abstract：:Human mesenchymal stem cells (hMSCs) were labeled with Ferucarbotran by simple incubation and cultured for up to 14 d. Iron content was determined by spectrometry and the intracellular localization of the contrast agent uptake was studied by electron and confocal microscopy. At various time points after labeling, rang...

journal_title：Magnetic resonance in medicine

authors： Henning TD,Wendland MF,Golovko D,Sutton EJ,Sennino B,Malek F,Bauer JS,McDonald DM,Daldrup-Link H

更新日期：2009-08-01 00:00:00

abstract：:The properties of the image noise for selective averaging of phase-encoding lines have been investigated. For a given acquisition time, selective averaging results in a signal-to-noise ratio penalty compared to averaging all lines equally. In addition, selective averaging yields a non uniform distribution of noise cha...

journal_title：Magnetic resonance in medicine

authors： Mugler JP 3rd

更新日期：1991-05-01 00:00:00

abstract：PURPOSE:Acquisition of high-resolution imaging data using multiple excitations without the sensitivity to fluctuations of the transverse magnetization phase, which is a major problem of multi-shot MRI. THEORY AND METHODS:The concept of superresolution MRI based on microscopic tagging is analyzed using an analogy with ...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Tian R,Engel M,Pruessmann KP

更新日期：2018-12-01 00:00:00

abstract：:The clinical application of 3D proton spectroscopic imaging (3D SI) of the human prostate requires a robust suppression of periprostatic lipid signal contamination, minimal intervoxel signal contamination, and the shortest possible measurement time. In this work, a weighted elliptical sampling of k-space, combined wit...

journal_title：Magnetic resonance in medicine

authors： Scheenen TW,Klomp DW,Röll SA,Fütterer JJ,Barentsz JO,Heerschap A

更新日期：2004-07-01 00:00:00

abstract：PURPOSE:To achieve artifact-suppressed whole-brain pass-band-balanced steady-state free precession functional MRI from a single functional magnetic resonance imaging (fMRI) scan. METHODS:A complete and practical data acquisition sequence for alt-SSFP fMRI was developed. First, multishot flyback-echo-planar imaging (EP...

journal_title：Magnetic resonance in medicine

authors： Jou T,Patterson S,Pauly JM,Bowen CV

更新日期：2016-05-01 00:00:00

abstract：:A new approach to autocalibrating, coil-by-coil parallel imaging reconstruction, is presented. It is a generalized reconstruction framework based on self-consistency. The reconstruction problem is formulated as an optimization that yields the most consistent solution with the calibration and acquisition data. The appr...

journal_title：Magnetic resonance in medicine

authors： Lustig M,Pauly JM

更新日期：2010-08-01 00:00:00

abstract：:In MRI, imaging using receiving coil arrays with a large number of elements is an area of growing interest. With increasing channel numbers for parallel acquisition, longer reconstruction times have become a significant concern. Channel reduction techniques have been proposed to reduce the processing time of channel-b...

journal_title：Magnetic resonance in medicine

authors： Huang F,Lin W,Duensing GR,Reykowski A

更新日期：2012-03-01 00:00:00

abstract：:With diffusion tensor imaging, the diffusion of water molecules through brain structures is quantified by parameters, which are estimated assuming monoexponential diffusion-weighted signal attenuation. The estimated diffusion parameters, however, depend on the diffusion weighting strength, the b-value, which hampers t...

journal_title：Magnetic resonance in medicine

authors： Veraart J,Poot DH,Van Hecke W,Blockx I,Van der Linden A,Verhoye M,Sijbers J

更新日期：2011-01-01 00:00:00

abstract：:Cirrhosis is an important and growing public health problem, affecting millions of Americans and many more people internationally. A pathological hallmark of the progression to cirrhosis is the development of liver fibrosis, so that monitoring the appearance and progression of liver fibrosis can be used to guide thera...

journal_title：Magnetic resonance in medicine

authors： Chung S,Breton E,Mannelli L,Axel L

更新日期：2011-04-01 00:00:00

abstract：PURPOSE:In diffusion MRI, the actual b-value played out on the scanner may deviate from the nominal value due to magnetic field imperfections. A simple image-based correction method for this problem is presented. METHODS:The apparent diffusion constant (ADC) of a water phantom was measured voxel-wise along 64 diffusio...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Kettinger AO,Wilm BJ,Deichmann R,Weiskopf N,Lambert C,Pruessmann KP,Nagy Z

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements. THEORY AND METHODS:An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into ...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Yan X,Gore JC,Grissom WA

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:To develop and test real-time MR elastography for viscoelastic parameter quantification in skeletal muscle during dynamic exercises. METHODS:In 15 healthy participants, 6 groups of lower-leg muscles (tibialis anterior, tibialis posterior, peroneus, extensor digitorum longus, soleus, gastrocnemius) were investi...

journal_title：Magnetic resonance in medicine

authors： Schrank F,Warmuth C,Görner S,Meyer T,Tzschätzsch H,Guo J,Uca YO,Elgeti T,Braun J,Sack I

更新日期：2020-07-01 00:00:00

abstract：:The MMQ cell line is a unique prolactin-secreting rat pituitary cell line. MMQ cells entrapped in agarose gel threads are metabolically active, as determined by the uptake and phosphorylation of creatine and the maintenance of high energy phosphates for over 15 h. Forskolin activates the catalytic subunit of adenylyl ...

journal_title：Magnetic resonance in medicine

authors： Goger MJ,Login IS,Fernandez EJ,Grisham CM

更新日期：1994-11-01 00:00:00

abstract：PURPOSE:To develop a method to correct for geometric distortions in non-Cartesian echo planar imaging using data acquired in a fast prescan. METHODS:Echo planar images were obtained using a non-Cartesian density weighted k-space trajectory. In contrast to linear Cartesian acquisition, distortions arising in non-Cartes...

journal_title：Magnetic resonance in medicine

authors： Zeller M,Müller A,Hahn D,Köstler H

更新日期：2014-03-01 00:00:00

abstract：PURPOSE:Nicotinamide adenine dinucleotide (NAD), in oxidized (NAD(+) ) or reduced (NADH) form, plays key roles in cellular metabolism. Intracellular NAD(+) /NADH ratio represents the cellular redox state; however, it is difficult to measure in vivo. We report here a novel in vivo (31) P MRS method for noninvasive measu...

journal_title：Magnetic resonance in medicine

authors： Lu M,Zhu XH,Zhang Y,Chen W

更新日期：2014-06-01 00:00:00

abstract：:Echo-planar spectroscopic imaging (EPSI) can be used for fast spectroscopic imaging of water and fat resonances at high resolution to improve structural and functional imaging. Because of the use of oscillating gradients during the free induction decay (FID), spectra obtained with EPSI are often degraded by Nyquist gh...

journal_title：Magnetic resonance in medicine

authors： Du W,Du YP,Fan X,Zamora MA,Karczmar GS

更新日期：2003-06-01 00:00:00