Measurements of T(1) -relaxation in ex vivo prostate tissue at 132 μT.

abstract：:The intra-individual and inter-individual variations of the global N-acetylaspartate (NAA) concentration were measured in a cohort of five 42+/-5 year-old normal females. The total NAA signal from the whole head was obtained with non-localized non-echo proton spectroscopy (1H-MRS) and converted into absolute mole amou...

journal_title：Magnetic resonance in medicine

authors： Gonen O,Viswanathan AK,Catalaa I,Babb J,Udupa J,Grossman RI

更新日期：1998-11-01 00:00:00

abstract：:Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arteri...

journal_title：Magnetic resonance in medicine

authors： Newbould RD,Skare ST,Jochimsen TH,Alley MT,Moseley ME,Albers GW,Bammer R

更新日期：2007-07-01 00:00:00

abstract：:The effects of macroscopic background field gradients upon 2D gradient echo images of inhaled (3)He in the human lung were investigated at 1.5 T. Effective compensation of in-slice signal loss in (3)He gradient echo images was then demonstrated using a multiple acquisition interleaved single gradient echo sequence. Th...

journal_title：Magnetic resonance in medicine

authors： Wild JM,Fichele S,Woodhouse N,Paley MN,Swift A,Kasuboski L,van Beek EJ

更新日期：2003-08-01 00:00:00

abstract：:Proton-observed carbon-edited (POCE) NMR spectroscopy is commonly used to measure 13C labeling with higher sensitivity compared to direct 13C NMR spectroscopy, at the expense of spectral resolution. For weakly coupled first-order spin systems, the multiplet signal at a specific proton chemical shift in POCE spectra di...

journal_title：Magnetic resonance in medicine

authors： Henry PG,Marjanska M,Walls JD,Valette J,Gruetter R,Ugurbil K

更新日期：2006-02-01 00:00:00

abstract：:The design of a piezoelectric-controlled trimmer capacitor and its use as a tuning element of an MRI surface coil at 63.8 MHz are described. It is found that image quality does not depend strongly on match of the coil to the transmission line but that tuning can be a significant factor. The work is intended to lead ev...

journal_title：Magnetic resonance in medicine

authors： Hyde JS,Rilling RJ,Jesmanowicz A,Kneeland JB

更新日期：1989-10-01 00:00:00

abstract：:In the present work, diffusion-weighted (DW)-NMR spectroscopy of glutamate was performed during a (13)C-labeled glucose infusion in monkey brain (six experiments). It is shown that glutamate (13)C labeling occurs significantly faster at higher diffusion weightings-slightly for glutamate in position C4, and more marked...

journal_title：Magnetic resonance in medicine

authors： Valette J,Chaumeil M,Guillermier M,Bloch G,Hantraye P,Lebon V

更新日期：2008-08-01 00:00:00

abstract：PURPOSE:To develop and validate a method for choosing the optimal two-dimensional CAIPIRINHA kernel for subtraction contrast-enhanced MR angiography (CE-MRA) and estimate the degree of image quality improvement versus that of some reference acceleration parameter set at R ≥ 8. METHODS:A metric based on patient-specifi...

journal_title：Magnetic resonance in medicine

authors： Weavers PT,Borisch EA,Riederer SJ

更新日期：2015-06-01 00:00:00

abstract：:The utility of a noninvasive steady state susceptibility-contrast MRI technique for continuous measurement of relative cerebral blood volume (rCBV) during global transient ischemia and subsequent hyperemia in a feline ischemia model is demonstrated. The measurements were obtained during a 10-min period of occlusion an...

journal_title：Magnetic resonance in medicine

authors： Hamberg LM,Boccalini P,Stranjalis G,Hunter GJ,Huang Z,Halpern E,Weisskoff RM,Moskowitz MA,Rosen BR

更新日期：1996-02-01 00:00:00

abstract：:A new ultrafast MR imaging method is proposed and tested, which enables whole-brain fMRI with a true temporal resolution of 1 sec. The method combines a 3D PRESTO pulse sequence with the concept of sensitivity-encoding with multiple receiver coils (SENSE). The so-called PRESTO-SENSE technique is demonstrated on a set ...

journal_title：Magnetic resonance in medicine

authors： Golay X,Pruessmann KP,Weiger M,Crelier GR,Folkers PJ,Kollias SS,Boesiger P

更新日期：2000-06-01 00:00:00

abstract：PURPOSE:Vulnerable atherosclerotic plaques are structurally weak and prone to rupture, presumably due to local oxidative stress. Redox active iron is linked to oxidative stress and the aim of this study was to investigate the distribution of Fe(III) in carotid plaques and its relation to vulnerability for rupture. MET...

journal_title：Magnetic resonance in medicine

authors： Gustafsson H,Hallbeck M,Norell M,Lindgren M,Engström M,Rosén A,Zachrisson H

更新日期：2014-02-01 00:00:00

abstract：:Diffusion tensor imaging (DTI) is a new imaging modality that can provide unique information on brain white matter anatomy. Measurements of water diffusion constant along multiple axes are fitted to a tensor model, from which the diffusion anisotropy and dominant fiber orientation can be estimated. Even though the ten...

journal_title：Magnetic resonance in medicine

authors： Zhang J,van Zijl PC,Mori S

更新日期：2006-02-01 00:00:00

abstract：PURPOSE:To develop and validate closed form mathematical expressions that predict the optimal contrast agent concentration for the maximum T1-weighted spoiled gradient echo (SGRE) signal. THEORY AND METHODS:Gadolinium and iron-based contrast agents can have significant transverse relaxivity that leads to signal dropou...

journal_title：Magnetic resonance in medicine

authors： Reeder SB,Smith MR,Hernando D

更新日期：2016-04-01 00:00:00

abstract：:Calculations and experiments that provide support for our previously stated theorem are presented: If two coils simultaneously receiving magnetic resonance signals from the same anatomic region exhibit zero mutual inductance, there can be no correlation of the noise. It is shown that correlation does not exist even in...

journal_title：Magnetic resonance in medicine

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

更新日期：1991-07-01 00:00:00

abstract：:The aim of this study was to quantify changes in thoracic aortic wall shear stress (WSS) in asymptomatic patients with Marfan syndrome (MFS) compared with healthy controls. WSS in the thoracic aorta was quantified based on time-resolved 3D phase contrast MRI with three-directional velocity encoding (4D flow MRI, tempo...

journal_title：Magnetic resonance in medicine

authors： Geiger J,Arnold R,Herzer L,Hirtler D,Stankovic Z,Russe M,Langer M,Markl M

更新日期：2013-10-01 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：:Free induction decay signals are analyzed by fitting a model function directly in the time domain. No starting values are needed for linear model parameters, and omission of corrupted data points poses no problems. A significant gain of accuracy is achieved by imposing prior knowledge about the model parameters. ...

journal_title：Magnetic resonance in medicine

authors： van der Veen JW,de Beer R,Luyten PR,van Ormondt D

更新日期：1988-01-01 00:00:00

abstract：PURPOSE:To develop a practical method for mapping macromolecule distribution in the brain using ultrashort-TE MRSI data. METHODS:An FID-based chemical shift imaging acquisition without metabolite-nulling pulses was used to acquire ultrashort-TE MRSI data that capture the macromolecule signals with high signal-to-noise...

journal_title：Magnetic resonance in medicine

authors： Lam F,Li Y,Clifford B,Liang ZP

更新日期：2018-05-01 00:00:00

abstract：:Dynamic contrast-enhanced MRI data in vertebral bone marrow (vBM) are currently analyzed with descriptive indices. The purpose of this study was to develop and evaluate a quantitative approach, considering the tissue composition of vBM. Therefore, a measurement of the water fraction, f(wat), and the precontrast relaxa...

journal_title：Magnetic resonance in medicine

authors： Biffar A,Sourbron S,Schmidt G,Ingrisch M,Dietrich O,Reiser MF,Baur-Melnyk A

更新日期：2010-07-01 00:00:00

abstract：:Two different types of (co-registered) images of the same slice of tissue will generally have different spatial resolutions. The judicious pixel-by-pixel combination of their data can be accomplished to yield a single image exhibiting properties of both. Here, axial (18)FDG PET and (1)H(2)O MR images of the human brai...

journal_title：Magnetic resonance in medicine

authors： Sammi MK,Felder CA,Fowler JS,Lee JH,Levy AV,Li X,Logan J,Pályka I,Rooney WD,Volkow ND,Wang GJ,Springer CS Jr

更新日期：1999-08-01 00:00:00

abstract：:Cerebral metabolite concentrations and water content were measured by means of localized proton magnetic resonance spectroscopy in 50 children, while metabolite peak ratios in short echo time spectra were evaluated in 173 examinations. Normative curves for normal development were established for two cerebral locations...

journal_title：Magnetic resonance in medicine

authors： Kreis R,Ernst T,Ross BD

更新日期：1993-10-01 00:00:00

abstract：:A pulse sequence is presented for obtaining a single image with combined T1/T2 weighting. T2 relaxation is made to increase intensity, in cooperation with the effect of T1 relaxation, by providing T2 weighting with a 90 degrees-180 degrees-90 degrees driven inversion pulse triplet in an inversion recovery method. Unli...

journal_title：Magnetic resonance in medicine

authors： Conturo TE,Kessler RM,Beth AH

更新日期：1990-09-01 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：:Variable nutation SSFP (DESPOT2) permits rapid, high-resolution determination of the transverse (T2) relaxation constant. A limitation of DESPOT2, however, is the presence of T2 voids due to off-resonance banding artifacts associated with SSFP images. These artifacts typically occur in images acquired with long repeti...

journal_title：Magnetic resonance in medicine

authors： Deoni SC,Ward HA,Peters TM,Rutt BK

更新日期：2004-08-01 00:00:00

abstract：:19F NMR imaging of the perfluorocarbon emulsion Fluosol has been used to study regional variations in oxygen tension in rat liver and spleen. We have used the linear dependence of spin lattice relaxation rate (1/T1) on the partial oxygen pressure (pO2) of Fluosol to determine the oxygen tension in the reticuloendothel...

journal_title：Magnetic resonance in medicine

authors： Holland SK,Kennan RP,Schaub MM,D'Angelo MJ,Gore JC

更新日期：1993-04-01 00:00:00

abstract：:Passive MR tracking of catheters and guidewires is usually done by dynamically imaging a single thick slab, subtracting a baseline image, and combining the result with a previously acquired MR angiogram. In the in vitro and in vivo experiments reported here, it is demonstrated that this approach may be greatly simplif...

journal_title：Magnetic resonance in medicine

authors： Bakker CJ,Bos C,Weinmann HJ

更新日期：2001-01-01 00:00:00

abstract：:Metallic implants, such as stents, have long been a concern in magnetic resonance imaging (MRI). In addition to safety issues, they are commonly associated with image artifacts. The mechanisms of radiofrequency- (RF) and susceptibility-induced artifacts have been thoroughly investigated. However, gradient-switching-in...

journal_title：Magnetic resonance in medicine

authors： Shenhav A,Azhari H

更新日期：2004-12-01 00:00:00

abstract：PURPOSE:To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS:Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI ...

journal_title：Magnetic resonance in medicine

authors： Cho GY,Moy L,Zhang JL,Baete S,Lattanzi R,Moccaldi M,Babb JS,Kim S,Sodickson DK,Sigmund EE

更新日期：2015-10-01 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：PURPOSE:To develop an MRI acquisition and reconstruction framework for volumetric cine visualization of the fetal heart and great vessels in the presence of maternal and fetal motion. METHODS:Four-dimensional (4D) depiction was achieved using a highly-accelerated multi-planar real-time balanced steady-state free prece...

journal_title：Magnetic resonance in medicine

authors： van Amerom JFP,Lloyd DFA,Deprez M,Price AN,Malik SJ,Pushparajah K,van Poppel MPM,Rutherford MA,Razavi R,Hajnal JV

更新日期：2019-09-01 00:00:00

abstract：:The use of phase correlation to detect rigid-body translational motion is reviewed and applied to individual echotrains in turbo-spin-echo data acquisition. It is shown that when the same echotrain is acquired twice, the subsampled correlation provides an array of delta-functions, from which the motion that occurred b...

journal_title：Magnetic resonance in medicine

authors： Mendes J,Kholmovski E,Parker DL

更新日期：2009-03-01 00:00:00