Abstract:
:A simple (2)H NMR method for quantifying absolute (2)H-enrichments in all seven aliphatic positions of glucose following its derivatization to monoacetone glucose is presented. The method is based on the addition of a small quantity of (2)H-enriched formate to the NMR sample. When the method was applied to [2-(2)H]monoacetone glucose samples prepared from [2-(2)H]glucose standards of known enrichments in the range of 0.2-2.5%, enrichment estimates derived by the NMR method were in good agreement with the real enrichment values of the [2-(2)H]glucose precursors. The measurement was also applied to monoacetone glucose derived from human plasma glucose samples following administration of (2)H(2)O and attainment of isotopic steady state, where glucose H2 and body water enrichment are equivalent. In these studies, the absolute H2 enrichment of plasma glucose estimated by the formate method was in good agreement with the (2)H-enrichment of body water measured by an independent method.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Jones JG,Perdigoto R,Rodrigues TB,Geraldes CFdoi
10.1002/mrm.10234subject
Has Abstractpub_date
2002-09-01 00:00:00pages
535-9issue
3eissn
0740-3194issn
1522-2594journal_volume
48pub_type
杂志文章abstract::Cardiac metabolism was studied with 31P NMR in 7 dogs and 4 cats to determine whether animals adapted for different life-styles (stalk and sprint vs endurance running) respond to increased work loads (heart rate X blood pressure product) with different high-energy phosphate kinetics. Hearts were exposed via a left lat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910040203
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abstract::The resolution and homogeneity limitations of echo-planar imaging (EPI) are overcome by zoom imaging of an easily shimmed localized volume. Use of the stimulated echo enables single-shot localization. In vivo 0.5-mm resolution EPI images of selected regions of a cat brain at 4.7 T are presented. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910140225
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abstract:PURPOSE:It has been shown, theoretically and in vivo, that using the Stejskal-Tanner pulsed-gradient, or linear tensor encoding (LTE), and in tissue exhibiting a "stick-like" diffusion geometry, the direction-averaged diffusion-weighted MRI signal at high b-values ( ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2020-09-01 00:00:00
abstract::The somatotopical organization of the human somatosensory cortex was analyzed with echo-planar imaging at 1.5 Tesla, utilizing deoxyhemoglobin as an endogenous contrast medium. Scrubbing stimulation at a frequency of 3 Hz was applied to one of three cutaneous areas: toes, fingertips, and tongue tip. Parasagittal echo-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910330521
更新日期:1995-05-01 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
pub_type: 杂志文章
doi:10.1002/mrm.25675
更新日期:2016-04-01 00:00:00
abstract:PURPOSE:To directly compare in vivo versus postmortem second-order motion-compensated spin-echo diffusion tensor imaging of the porcine heart. METHODS:Second-order motion-compensated spin-echo cardiac diffusion tensor imaging was performed during systolic contraction in vivo and repeated upon cardiac arrest by bariumc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26871
更新日期:2018-04-01 00:00:00
abstract::To quantify metabolite and cation concentrations using NMR spectroscopy, the volumes of intracellular and extracellular spaces must be known. We describe a simple 31P NMR spectroscopic method that employs dimethyl methylphosphonate (DMMP) as a marker of total water space and phenylphosphonate (PPA) as a marker of extr...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320206
更新日期:1994-08-01 00:00:00
abstract::New algorithms for correlation analysis are presented that allow the mapping of brain activity from functional MRI (fMRI) data in real time during the ongoing scan. They combine the computation of the correlation coefficients between measured fMRI time-series data and a reference vector with "detrending", a technique ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(200002)43:2<259::aid-mrm13
更新日期:2000-02-01 00:00:00
abstract::In this study, we report the use of a novel ultrashort echo time T(1)rhoT(1) sequence that combines a spin-lock preparation pulse with a two-dimensional ultrashort echo time sequence of a nominal echo time 8 microsec. The ultrashort echo time-T(1)rho sequence was employed to quantify T(1)rho in short T(2) tissues incl...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22474
更新日期:2010-09-01 00:00:00
abstract::Single-slab 3D turbo/fast spin echo (SE) imaging with very long echo trains was recently introduced with slab selection using a highly selective excitation pulse and short, nonselective refocusing pulses with variable flip angles for high imaging efficiency. This technique, however, is vulnerable to image degradation ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.22070
更新日期:2009-10-01 00:00:00
abstract::A multifocal mouse liver tumor model chemically induced with 5,9-dimethyl-7H-dibenzo[c,g]carbazole was investigated by respiratory-triggered morphological and functional MRI (fMRI) at 4.7 Tesla. The model is characterized by the presence of two tumor types: hypovascular cholangioma and vascularized hepatocellular carc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10555
更新日期:2003-09-01 00:00:00
abstract:PURPOSE:To illustrate the potential bias caused by imaging gradients in correlation MRI sequences using longitudinal magnetization storage (LS) and examine the case of filter exchange imaging (FEXI) yielding maps of the apparent exchange rate (AXR). METHODS:The effects of imaging gradients in FEXI were observed on yea...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26856
更新日期:2018-04-01 00:00:00
abstract::For diffusion-weighted magnetic resonance imaging and under circumstances where patient movement can be modeled as rigid body motion, it is shown both theoretically and experimentally that translations and rotations produce phase errors which are zero- and first-order, respectively, in position. While a navigator echo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320313
更新日期:1994-09-01 00:00:00
abstract:PURPOSE:To investigate the influence of transcytolemmal water exchange on estimates of tissue microstructural parameters derived from diffusion MRI using conventional PGSE and IMPULSED methods. METHODS:Computer simulations were performed to incorporate a broad range of intracellular water life times τin (50-∞ ms), cel...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26309
更新日期:2017-06-01 00:00:00
abstract::Dynamic susceptibility contrast (DSC) MRI is now increasingly used for measuring perfusion in many different applications. The quantification of DSC data requires the measurement of the arterial input function (AIF) and the deconvolution of the tissue concentration time curve. One of the most accepted deconvolution me...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200009)44:3<466::aid-mrm18>3.0.c
更新日期:2000-09-01 00:00:00
abstract::Longitudinal water proton relaxation rates of methemoglobin solutions show a strong dependence on temperature and pH. The increase of the relaxation rates with temperature is associated with shortened exchange lifetime of the coordinated water molecule. An accurate measurement of the relaxation rate of methemoglobin s...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910330613
更新日期:1995-06-01 00:00:00
abstract::Chemical shifts were extracted from in vivo 3-dimensional 31P NMR CSI data and pH images were constructed. The images could spatially resolve tissue pH ranging from 5.8 to 7.2 (with uncertainty of 0.11-0.17 pH unit) in an ischemia-reperfusion model of diabetic rat calf muscles. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290214
更新日期:1993-02-01 00:00:00
abstract::MR-thermometry allows monitoring of the local temperature evolution during minimally invasive interventional therapies. However, for the particular case of MR-thermometry in the human breast, magnetic field variations induced by the respiratory cycle lead to phase fluctuations requiring a suitable correction strategy ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21954
更新日期:2009-06-01 00:00:00
abstract:PURPOSE:To demonstrate feasibility of transceive phase mapping with the PLANET method and its application for conductivity reconstruction in the brain. METHODS:Accuracy and precision of transceive phase (ϕ± ) estimation with PLANET, an ellipse fitting approach to phase-cycled balanced steady state free precession (bSS...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27958
更新日期:2020-02-01 00:00:00
abstract::In the recently proposed technique Sweep Imaging with Fourier Transform (SWIFT), frequency-modulated radiofrequency pulses are used in concert with simultaneous acquisition to facilitate MRI of samples with very short transverse relaxation time. In the present work, sweep MRI is reviewed from a reconstruction perspect...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.22516
更新日期:2010-12-01 00:00:00
abstract::Noninvasive molecular imaging of angiogenesis could play a critical role in the clinical management of peripheral vascular disease patients. The alpha(nu)beta(3)-integrin, a well-established biomarker of neovascular proliferation, is an ideal target for molecular imaging of angiogenesis. This study investigates whethe...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22447
更新日期:2010-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25720
更新日期:2016-05-01 00:00:00
abstract::Image reconstruction of tagged cardiac MR images using complementary spatial modulation of magnetization (CSPAMM) requires the subtraction of two complex datasets to remove the untagged signal. Although the resultant images typically have sharper and more persistent tags than images formed without complementary taggin...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10523
更新日期:2003-08-01 00:00:00
abstract:PURPOSE:To significantly reduce the background phase effects, especially at the air-tissue interface, and to enhance the desirable local structures of veins in susceptibility-weighted imaging. METHODS:In the proposed reconstruction method called Magnitude of Complex Filtering, a complex-valued magnetic resonance image...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24776
更新日期:2014-03-01 00:00:00
abstract::Magnetic resonance images of the lungs of a guinea pig have been produced using hyperpolarized helium as the source of the MR signal. The resulting images are not yet sufficiently optimized to reveal fine structural detail within the lung, but the spectacular signal from this normally signal-deficient organ system off...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910330219
更新日期:1995-02-01 00:00:00
abstract::The apparent diffusion coefficient (ADC) in the optic nerve was measured from diffusion-weighted magnetic resonance imaging using an intravoxel incoherent motion (IVIM) sequence. The subjects were seven normal volunteers and eight patients with multiple sclerosis (MS) with a total of four optic nerves with acute neuri...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910380317
更新日期:1997-09-01 00:00:00
abstract:PURPOSE:To achieve rapid, high resolution whole-brain gray matter (GM) imaging by developing a novel, single-slab three-dimensional dual-echo fast-spin-echo pulse sequence and GM-selective reconstruction. METHODS:Unlike conventional GM imaging that uses time-consuming double-inversion-recovery preparation, the propose...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26910
更新日期:2017-11-01 00:00:00
abstract:PURPOSE:Atherosclerotic carotid plaques can be quantified in vivo by MRI. However, the accuracy in segmentation and quantification of components such as the thin fibrous cap (FC) and lipid-rich necrotic core (LRNC) remains unknown due to the lack of a submillimeter scale ground truth. METHODS:A novel approach was take...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24905
更新日期:2014-07-01 00:00:00
abstract::Quantitative MRI assessment of leukoencephalopathy is difficult because the MRI properties of leukoencephalopathy significantly overlap those of normal tissue. This report describes the use of an automated procedure for longitudinal measurement of tissue volume and relaxation times to quantify leukoencephalopathy. Ima...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章,随机对照试验
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更新日期:2002-05-01 00:00:00
abstract::SENSE reconstruction suffers from an ill-conditioning problem, which increasingly lowers the signal-to-noise ratio (SNR) as the reduction factor increases. Ill-conditioning also degrades the convergence behavior of iterative conjugate gradient reconstructions for arbitrary trajectories. Regularization techniques are o...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.21665
更新日期:2008-08-01 00:00:00