Shaped saturation with inherent radiofrequency-power-efficient trajectory design in parallel transmission.

abstract：PURPOSE:To compare the performance of an 8-channel surface coil/clamshell transmitter and 32-channel head array coil/birdcage transmitter for hyperpolarized 13 C brain metabolic imaging. METHODS:To determine the field homogeneity of the radiofrequency transmitters, B1 + mapping was performed on an ethylene glycol head...

journal_title：Magnetic resonance in medicine

authors： Autry AW,Gordon JW,Carvajal L,Mareyam A,Chen HY,Park I,Mammoli D,Vareth M,Chang SM,Wald LL,Xu D,Vigneron DB,Nelson SJ,Li Y

更新日期：2019-08-01 00:00:00

abstract：PURPOSE:To investigate four-dimensional flow denoising using the divergence-free wavelet (DFW) transform and compare its performance with existing techniques. THEORY AND METHODS:DFW is a vector-wavelet that provides a sparse representation of flow in a generally divergence-free field and can be used to enforce "soft" ...

journal_title：Magnetic resonance in medicine

authors： Ong F,Uecker M,Tariq U,Hsiao A,Alley MT,Vasanawala SS,Lustig M

更新日期：2015-02-01 00:00:00

abstract：:Paramagnetic ions complexed to proteins may lose, retain, or enhance solvent paramagnetic relaxation (SPR) relative to free solution. We measured T1 and T2 of three mouse cancers, their normal counterparts, and six additional tissues. Long T1 of cancers was not caused by necrosis or by different contents of water, fat...

journal_title：Magnetic resonance in medicine

authors： Negendank W,Corbett T,Crowley M,Kellogg C

更新日期：1991-04-01 00:00:00

abstract：:The ultra-fast application of the RARE experiment is described in detail, with special emphasis on its multifarious applications with preparation experiments that produce transverse magnetization. The factors affecting the temporal evolution of the magnetization during the experiment are described, and the implication...

journal_title：Magnetic resonance in medicine

authors： Norris DG,Börnert P,Reese T,Leibfritz D

更新日期：1992-09-01 00:00:00

abstract：:Focused ultrasound heating of ex vivo bovine kidney and liver was monitored using magnetic resonance imaging (MRI) to investigate the quantitative relationship between time-dependent temperature elevations and altered contrast in MR images due to thermal coagulation. Proton resonance frequency shift MR thermometry was...

journal_title：Magnetic resonance in medicine

authors： Graham SJ,Chen L,Leitch M,Peters RD,Bronskill MJ,Foster FS,Henkelman RM,Plewes DB

更新日期：1999-02-01 00:00:00

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：PURPOSE:Spiral readouts combine several favorable properties that promise superior net sensitivity for diffusion imaging. The purpose of this study is to verify the signal-to-noise ratio (SNR) benefit of spiral acquisition in comparison with current echo-planar imaging (EPI) schemes. METHODS:Diffusion-weighted in vivo...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Wilm BJ,Brunner DO,Gross S,Schmid T,Nagy Z,Pruessmann KP

更新日期：2021-04-01 00:00:00

abstract：PURPOSE:To improve the specific absorption rate (SAR) compression model capability in parallel transmission (pTx) MRI systems. METHODS:A k-means clustering method is proposed to group voxels with similar SAR behaviors in the scanned object, providing a controlled upper-bounded estimation of peak local SARs. This k-mea...

journal_title：Magnetic resonance in medicine

authors： Mao X,Bari S,Love DJ,Rispoli JV

更新日期：2021-02-01 00:00:00

abstract：:In a systematic study on the interdependence of linewidth, signal-to-noise ratio (SNR), and spatial resolution in 3D proton spectroscopic imaging ((1)H-SI) at 3 T, we demonstrate reduced linewidths with increased spatial resolution due to reduced magnetic inhomogeneity within the brain. High-precision quantitative dat...

journal_title：Magnetic resonance in medicine

authors： Gruber S,Mlynárik V,Moser E

更新日期：2003-02-01 00:00:00

abstract：PURPOSE:To perform quantitative susceptibility mapping (QSM) in negligible acquisition time and apply it to measuring iron-rich subcortical gray matter. METHODS:Whole brain QSM was performed using single-shot gradient echo-planar imaging (EPI) in under 7 seconds on a standard 1.5 T system for imaging brain iron in sub...

journal_title：Magnetic resonance in medicine

authors： Sun H,Wilman AH

更新日期：2015-05-01 00:00:00

abstract：:Cell death by apoptosis is critical in myocardial diseases, and noninvasive detection of early, reversible apoptosis might be useful clinically. Exogenous Annexin-V (ANX) protein binds membrane phosphatidylserine, which is externalized in early apoptosis. A molecular MRI probe was constructed with superparamagnetic ir...

journal_title：Magnetic resonance in medicine

authors： Dash R,Chung J,Chan T,Yamada M,Barral J,Nishimura D,Yang PC,Simpson PC

更新日期：2011-10-01 00:00:00

abstract：:NMRD profiles, the magnetic field dependence of the water proton longitudinal relaxation rates, have been acquired for two new diphosphonate-modified GdDTPA complexes currently under evaluation as relaxation agents for the MRI detection of soft-tissue calcifications. Fresh dilute solutions show profiles identical to t...

journal_title：Magnetic resonance in medicine

authors： Adzamli IK,Blau M

更新日期：1991-01-01 00:00:00

abstract：PURPOSE:To assess the feasibility of using dissolved hyperpolarized xenon-129 (129 Xe) MRI to study renal physiology in humans at 3 T. METHODS:Using a flexible transceiver RF coil, dynamic and spatially resolved 129 Xe spectroscopy was performed in the abdomen after inhalation of hyperpolarized 129 Xe gas with 3 healt...

journal_title：Magnetic resonance in medicine

authors： Chacon-Caldera J,Maunder A,Rao M,Norquay G,Rodgers OI,Clemence M,Puddu C,Schad LR,Wild JM

更新日期：2020-01-01 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：PURPOSE:To measure the apparent diffusion coefficients (ADC) of five main metabolites in the human brain at 3T with PRESS and STEAM, avoiding measurement biases because of cross-terms. Cross-terms arise from interactions between slice-selection and spoiler gradients in the localized spectroscopy sequence and the diffus...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Auerbach EJ,Marjańska M

更新日期：2018-06-01 00:00:00

abstract：:High-resolution turbo spin echo (TSE) images have demonstrated important details of carotid artery morphology; however, it is evident that pulsatile blood and wall motion related to the cardiac cycle are still significant sources of image degradation. Although ECG gating can reduce artifacts due to cardiac-induced pul...

journal_title：Magnetic resonance in medicine

authors： Mendes J,Parker DL,Hulet J,Treiman GS,Kim SE

更新日期：2011-11-01 00:00:00

abstract：:A novel radio-frequency (RF) pulse design algorithm is presented that generates fast slice-selective excitation pulses that mitigate B+1 inhomogeneity present in the human brain at high field. The method is provided an estimate of the B+1 field in an axial slice of the brain and then optimizes the placement of sinc-li...

journal_title：Magnetic resonance in medicine

authors： Zelinski AC,Wald LL,Setsompop K,Alagappan V,Gagoski BA,Goyal VK,Adalsteinsson E

更新日期：2008-06-01 00:00:00

abstract：:The relative distributions of N-acetylaspartate (NAA) + N-acetylaspartylglutamate (NAAG), creatine + phosphocreatine (Cr/PCr), and choline (Cho) in the gray and white matter of human brain were determined by utilizing proton magnetic resonance spectroscopic imaging (SI). The SI data was processed using an automated sp...

journal_title：Magnetic resonance in medicine

authors： Doyle TJ,Bedell BJ,Narayana PA

更新日期：1995-06-01 00:00:00

abstract：:Diffusion tensor imaging is gaining increasing importance for anatomical imaging of the developing mouse brain. However, the application of diffusion tensor imaging to mouse brain imaging at microscopic levels is hindered by the limitation on achievable spatial resolution. In this study, fast diffusion tensor microima...

journal_title：Magnetic resonance in medicine

authors： Aggarwal M,Mori S,Shimogori T,Blackshaw S,Zhang J

更新日期：2010-07-01 00:00:00

abstract：:A MultiEcho Segmented EPI with z-shimmed BAckground gradient Compensation (MESBAC) pulse sequence is proposed and validated for functional MRI (fMRI) study in regions suffering from severe susceptibility artifacts. This sequence provides an effective tradeoff between spatial and temporal resolution and reduces image d...

journal_title：Magnetic resonance in medicine

authors： Li Z,Wu G,Zhao X,Luo F,Li SJ

更新日期：2002-08-01 00:00:00

abstract：:A gradient technique to measure electron paramagnetic resonance spectra simultaneously at several different locations is described. The technique is based on the use of point probes containing paramagnetic centers. The value of the magnetic field gradient is chosen to be sufficient to separate the EPR signals from the...

journal_title：Magnetic resonance in medicine

authors： Smirnov AI,Norby SW,Clarkson RB,Walczak T,Swartz HM

更新日期：1993-08-01 00:00:00

abstract：:Dynamic MRI tracking of rat T-cells in vivo is performed in rat testicles after labeling isolated rat T-cells in vitro with superparamagnetic dextran-coated iron-oxide particles, BMS180549. Tissue inflammation induced by the local injection of the calcium ionophore, A23187, is used to attract labeled T-cells. Gradient...

journal_title：Magnetic resonance in medicine

authors： Yeh TC,Zhang W,Ildstad ST,Ho C

更新日期：1995-02-01 00:00:00

abstract：:In past decades, much effort has been invested in developing therapies for spinal injuries. Lack of standardization of clinical read-out measures, however, makes direct comparison of experimental therapies difficult. Damage and therapeutic effects in vivo are routinely evaluated using rather subjective behavioral test...

journal_title：Magnetic resonance in medicine

authors： Stieltjes B,Klussmann S,Bock M,Umathum R,Mangalathu J,Letellier E,Rittgen W,Edler L,Krammer PH,Kauczor HU,Martin-Villalba A,Essig M

更新日期：2006-05-01 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

authors： Ying L,Liu B,Steckner MC,Wu G,Wu M,Li SJ

更新日期：2008-08-01 00:00:00

abstract：:Diffusion-weighted imaging (DWI) is frequently used to diagnose stroke. However, the origin of the observed reduction in the apparent diffusion coefficient (ADC) in the acute phase following ischemia is not well understood. Although cell swelling is considered to play an important role, it is unclear whether this can ...

journal_title：Magnetic resonance in medicine

authors： van Pul C,Jennekens W,Nicolay K,Kopinga K,Wijn PF

更新日期：2005-02-01 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

authors： Reddick WE,Glass JO,Langston JW,Helton KJ

更新日期：2002-05-01 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 potential application of gas microbubbles as a unique intravascular susceptibility contrast agent for MRI has not been fully explored. In this study, the MR susceptibility effect of an ultrasound microbubble contrast agent, Optison, was studied with rat liver imaging at 7 T. Optison suspension in two different dos...

journal_title：Magnetic resonance in medicine

authors： Wong KK,Huang I,Kim YR,Tang H,Yang ES,Kwong KK,Wu EX

更新日期：2004-09-01 00:00:00

abstract：:To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were...

journal_title：Magnetic resonance in medicine

authors： Rose SE,Hatzigeorgiou X,Strudwick MW,Durbridge G,Davies PS,Colditz PB

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:Preclinical imaging of myocardial blood flow (MBF) can elucidate molecular mechanisms underlying cardiovascular disease. We compared the repeatability and variability of two methods, first-pass MRI and arterial spin labeling (ASL), for imaging MBF in mice. METHODS:Quantitative perfusion MRI in mice was perform...

journal_title：Magnetic resonance in medicine

authors： Naresh NK,Chen X,Moran E,Tian Y,French BA,Epstein FH

更新日期：2016-06-01 00:00:00