Efficient visualization of vascular territories in the human brain by cycled arterial spin labeling MRI.

abstract：:A novel linear parameterization for the variable flip angle method for longitudinal relaxation time T(1) quantification from spoiled steady state MRI is derived from the half angle tangent transform, τ, of the flip angle. Plotting the signal S at coordinates x=Sτ and y=S/τ, respectively, establishes a line that render...

journal_title：Magnetic resonance in medicine

authors： Helms G,Dathe H,Weiskopf N,Dechent P

更新日期：2011-09-01 00:00:00

abstract：:The manufacturing of intravascular imaging coils poses several challenges. Due to their size, it can be difficult to incorporate local matching networks and signal amplifiers. The goal of this study is to investigate tuning and amplification strategies for intravascular coils and to assess the signal-to-noise benefits...

journal_title：Magnetic resonance in medicine

authors： Yak N,Anderson KJ,Wright GA

更新日期：2012-11-01 00:00:00

abstract：PURPOSE:The objective of this study was to determine whether a sodium phased array would improve sodium breast MRI at 3 T. The secondary objective was to create acceptable proton images with the sodium phased array in place. METHODS:A novel composite array for combined proton/sodium 3 T breast MRI is compared with a c...

journal_title：Magnetic resonance in medicine

authors： Kaggie JD,Hadley JR,Badal J,Campbell JR,Park DJ,Parker DL,Morrell G,Newbould RD,Wood AF,Bangerter NK

更新日期：2014-06-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 00:00:00

abstract：PURPOSE:To demonstrate the feasibility of imaging the first passage of a bolus of hyperpolarized (13)C urea through the rodent heart using flow-sensitizing gradients to reduce signal from the blood pool. METHODS:A flow-sensitizing bipolar gradient was optimized to reduce the bright signal within the cardiac chambers, ...

journal_title：Magnetic resonance in medicine

authors： Lau AZ,Miller JJ,Robson MD,Tyler DJ

更新日期：2016-04-01 00:00:00

abstract：:A novel method for reducing the rf power requirements of selective pulses employed for z magnetization slice inversion in localized NMR spectroscopy is presented. Following slice preparation by the use of frequency-incremented sinc pulses, the slice gradient is reduced, which narrows the frequency width of the slice. ...

journal_title：Magnetic resonance in medicine

authors： Brereton IM,Brooks WM,Marshman MF,Field J,Doddrell DM

更新日期：1987-12-01 00:00:00

abstract：:Phase-contrast magnetic resonance imaging is subject to numerous sources of error, which decrease clinical confidence in the reported measures. This work outlines how stationary perivascular fat can impart a significant chemical shift induced phase-contrast magnetic resonance imaging measurement error using computatio...

journal_title：Magnetic resonance in medicine

authors： Middione MJ,Ennis DB

更新日期：2013-02-01 00:00:00

abstract：:Precise relaxation time (RT) measurements have been made, with a standard deviation of 3% for T1 and T2 in white matter in normal volunteers. This sets an upper limit to the instrumental random errors (imprecision). Achieving this precision requires careful adjustment and use of the imager. The wide variation in RTs s...

journal_title：Magnetic resonance in medicine

authors： Miller DH,Johnson G,Tofts PS,MacManus D,McDonald WI

更新日期：1989-09-01 00:00:00

abstract：:In this study, the precision and accuracy of a new method for measuring axial rotations of the lumbar vertebrae, which are thought to be increased in patients with degenerative spinal instability, were estimated. A standard image registration algorithm involving a user-selected center of rotation was adapted for this ...

journal_title：Magnetic resonance in medicine

authors： Rogers BP,Haughton VM,Arfanakis K,Meyerand ME

更新日期：2002-12-01 00:00:00

abstract：:Flow-independent angiography is a non-contrast-enhanced technique that can generate vessel contrast even with reduced blood flow in the lower extremities. A method is presented for producing these angiograms with magnetization-prepared balanced steady-state free precession (bSSFP). Because bSSFP yields bright fat sign...

journal_title：Magnetic resonance in medicine

authors： Cukur T,Lee JH,Bangerter NK,Hargreaves BA,Nishimura DG

更新日期：2009-06-01 00:00:00

abstract：:In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit mo...

journal_title：Magnetic resonance in medicine

authors： Nakai T,Rhine WD,Okada T,Stevenson DK,Spielman DM

更新日期：1998-10-01 00:00:00

abstract：:This study demonstrates the in vitro displacement and strain of articular cartilage in a cyclically-compressed and intact joint using displacement-encoded imaging with stimulated echoes (DENSE) and fast spin echo (FSE). Deformation and strain fields exhibited complex and heterogeneous patterns. The displacements in th...

journal_title：Magnetic resonance in medicine

authors： Chan DD,Neu CP,Hull ML

更新日期：2009-04-01 00:00:00

abstract：PURPOSE:Magnetization transfer ratio (MTR) histograms are used widely for the assessment of diffuse pathological changes in the brain. For broad clinical application, MTR scans should not only be fast, but confounding factors should also be minimized for high reproducibility. To this end, a 1-minute whole-brain spiral ...

journal_title：Magnetic resonance in medicine

authors： Afshari R,Santini F,Heule R,Meyer CH,Pfeuffer J,Bieri O

更新日期：2020-12-08 00:00:00

abstract：:The focal underdetermined system solver (FOCUSS) was originally designed to obtain sparse solutions by successively solving quadratic optimization problems. This article adapts FOCUSS for a projection reconstruction MR imaging problem to obtain high resolution reconstructions from angular under-sampled radial k-space ...

journal_title：Magnetic resonance in medicine

authors： Ye JC,Tak S,Han Y,Park HW

更新日期：2007-04-01 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：:Phase-contrast MRI can provide high-resolution angiographic velocity images, especially in conjunction with non-Cartesian k-space sampling. However, acquisitions can be sensitive to errors from artifacts from main magnetic field inhomogeneities and chemical shift from fat. Particularly in body imaging, fat content can...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Wieben O,Samsonov AA

更新日期：2010-06-01 00:00:00

abstract：:Although promising for visualizing the structure of ordered tissues, MR diffusion tensor imaging (DTI) has been hampered by long acquisition time and low spatial resolution associated with its inherently low signal-to-noise ratio (SNR). Moreover, the uncertainty in the DTI measurements has a direct impact on the accur...

journal_title：Magnetic resonance in medicine

authors： Chen B,Hsu EW

更新日期：2005-08-01 00:00:00

abstract：:Fast proton magnetic resonance spectroscopic imaging (MRSI) using a multi-element head-coil array is examined with respect to three aspects: the coil design, the use of an appropriate signal combination method, and the design of the MRSI pulse sequence itself. An eight-element head-coil array has been developed to inc...

journal_title：Magnetic resonance in medicine

authors： Schäffter T,Börnert P,Leussler C,Carlsen IC,Leibfritz D

更新日期：1998-08-01 00:00:00

abstract：:Diffusion-weighted MRI is a clinically useful technique, but its utility is compromised by high sensitivity to patient motion. Use of radial-scan data acquisition and projection reconstruction, rather than the conventional Fourier imaging method, can substantially reduce the sensitivity to global translational motion ...

journal_title：Magnetic resonance in medicine

authors： Gmitro AF,Alexander AL

更新日期：1993-06-01 00:00:00

abstract：:The investigation of flow behavior in coronary arteries is of great importance for an understanding of heart failure and heart regulation mechanisms. The purpose of the present study was to demonstrate that flow velocity can be quantified in the coronary arteries of the isolated rat heart with high-resolution phase co...

journal_title：Magnetic resonance in medicine

authors： Köhler S,Hiller KH,Jakob PM,Bauer WR,Haase A

更新日期：2003-09-01 00:00:00

abstract：PURPOSE:Respiratory organ motion is still the major challenge of various image-guided treatments in the abdomen. Dynamic organ motion tracking, necessary for the treatment control, can be performed with volumetric time-resolved MRI that sequentially acquires one image and one navigator slice. Here, a novel imaging meth...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Bieri O,Preiswerk F,Cattin P,Scheffler K,Santini F

更新日期：2015-02-01 00:00:00

abstract：:A lactate editing sequence based on the use of spin-locking pulses with surface coils is described. The sequence retains more than 90% of the available lactate magnetization and suppresses at least 95% of the lipid signal in a single scan and ca. 99.5% after a simple two step cycle. The technique allows simultaneous o...

journal_title：Magnetic resonance in medicine

authors： Bourgeois D,Kozlowski P

更新日期：1993-03-01 00:00:00

abstract：:A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equatio...

journal_title：Magnetic resonance in medicine

authors： Olsson MB,Wirestam R,Persson BR

更新日期：1995-10-01 00:00:00

abstract：:Applications of fMRI in functional brain imaging are mainly confined to single subject designs, prohibiting the assessment of subject or group by condition interactions (i.e., differential activations) or areas of conjoint activation. In this paper a framework for fMRI group designs, using statistical parametric mappi...

journal_title：Magnetic resonance in medicine

authors： Büchel C,Turner R,Friston K

更新日期：1997-11-01 00:00:00

abstract：:The purpose of the present study was to examine whether single human carcinoma cells labeled with iron oxide nanoparticles could be detected by magnetic resonance (MR) imaging on a clinical 3-T scanner using a surface coil only. WiDr human colon carcinoma cells were loaded with two kinds of iron oxide nanoparticles di...

journal_title：Magnetic resonance in medicine

authors： Pinkernelle J,Teichgräber U,Neumann F,Lehmkuhl L,Ricke J,Scholz R,Jordan A,Bruhn H

更新日期：2005-05-01 00:00:00

abstract：:A current limitation of many myocardial tag acquisitions employing SPAMM encoding is the relatively rapid loss of tag contrast over the cardiac cycle. Acquisition schemes that apply line tags produce prolonged tag contrast compared with directly excited grid tags. However, a grid-tag series can be generated by combini...

journal_title：Magnetic resonance in medicine

authors： Doyle M,Walsh EG,Foster RE,Pohost GM

更新日期：1997-05-01 00:00:00

abstract：PURPOSE:To accelerate whole-heart three-dimension MR angiography (MRA) by using a variable-density Poisson-disc undersampling pattern and a compressed sensing (CS) reconstruction algorithm, and compare the results with sensitivity encoding (SENSE). METHODS:For whole-heart MRA, a prospective variable-density Poisson-di...

journal_title：Magnetic resonance in medicine

authors： Moghari MH,Uecker M,Roujol S,Sabbagh M,Geva T,Powell AJ

更新日期：2018-02-01 00:00:00

abstract：:Intermolecular double quantum coherences (iDQCs), signals that result from simultaneous transitions of two or more separated spins, are known to produce images that are highly sensitive to subvoxel structure, particularly local anisotropy. Here we demonstrate how iDQCs signal can be used to efficiently detect the anis...

journal_title：Magnetic resonance in medicine

authors： Branca RT,Chen YM,Mouraviev V,Galiana G,Jenista ER,Kumar C,Leuschner C,Warren WS

更新日期：2009-04-01 00:00:00

abstract：:The ability to generate in vivo maps of lactate may have significant diagnostic utility in staging and treatment planning of a wide variety of cancers. The double selective multiple quantum filter technique (SelMQC) has been shown to be effective for nonlocalized detection of lactate with little or no interference fro...

journal_title：Magnetic resonance in medicine

authors： Pickup S,Lee SC,Mancuso A,Glickson JD

更新日期：2008-08-01 00:00:00

abstract：PURPOSE:The optic nerve (ON) represents the sole pathway between the eyes and brain; consequently, diseases of the ON can have dramatic effects on vision. However, quantitative magnetization transfer (qMT) applications in the ON have been limited to ex vivo studies, in part because of the fatty connective tissue that s...

journal_title：Magnetic resonance in medicine

authors： Smith AK,Dortch RD,Dethrage LM,Lyttle BD,Kang H,Welch EB,Smith SA

更新日期：2017-02-01 00:00:00