Iterative Next-Neighbor Regridding (INNG): improved reconstruction from nonuniformly sampled k-space data using rescaled matrices.

abstract：:The echo-planar k-space trajectory can be used as the basis for any two-dimensional selective pulse. The main application is spectral-spatial pulses, which must be based on the echo-planar trajectory. In this paper we show how echo-planar spin-echo (EPSE) pulses may be designed. ...

journal_title：Magnetic resonance in medicine

authors： Pauly J,Spielman D,Macovski A

更新日期：1993-06-01 00:00:00

abstract：PURPOSE:To develop a fast protocol for measuring T1 values in the internal carotid artery (ICA), to validate this technique with in vitro measurements, and to evaluate its reproducibility. METHODS:A modified Look-Locker sequence was optimized to enable rapid determination of T1 in the ICA at 3T. T1 values from the ICA...

journal_title：Magnetic resonance in medicine

authors： Li W,Liu P,Lu H,Strouse JJ,van Zijl PCM,Qin Q

更新日期：2017-06-01 00:00:00

abstract：:A multiple quantum filter strategy is presented for spectrally discriminating metabolites with strongly coupled spins from those whose spins are either uncoupled or weakly coupled. The strategy also includes a means for selectively suppressing the background multiplets of metabolites that also have strongly coupled sp...

journal_title：Magnetic resonance in medicine

authors： Kim H,Wild JM,Allen PS

更新日期：2004-02-01 00:00:00

abstract：PURPOSE:Spatio-temporal encoding (SPEN) experiments can deliver single-scan MR images without folding complications and with robustness to chemical shift and susceptibility artifacts. Further resolution improvements are shown to arise by relying on multiple receivers, to interpolate the sampled data along the low-bandw...

journal_title：Magnetic resonance in medicine

authors： Liberman G,Solomon E,Lustig M,Frydman L

更新日期：2018-02-01 00:00:00

abstract：:Perfusion imaging by arterial spin labeling (ASL) can be highly sensitive to the transit time from the labeling site to the tissue. We report the results of a study designed to separate the transit time and perfusion contributions to activation in ASL images accompanying motor and visual stimulation. Fractional transi...

journal_title：Magnetic resonance in medicine

authors： Gonzalez-At JB,Alsop DC,Detre JA

更新日期：2000-05-01 00:00:00

abstract：PURPOSE:Balanced steady state free precession (bSSFP) imaging suffers from off-resonance artifacts such as signal modulation and banding. Solutions for removal of bSSFP off-resonance dependence are described and compared, and an optimal solution is proposed. THEORY AND METHODS:An Algebraic Solution (AS) that complemen...

journal_title：Magnetic resonance in medicine

authors： Hoff MN,Andre JB,Xiang QS

更新日期：2017-02-01 00:00:00

abstract：:Most prostate MRI/MRS examinations are performed with an endorectal coil inflated with air, leading to an air-tissue interface that induces magnetic susceptibility gradients within the gland. Inflation of the coil with a barium sulfate suspension is described and compared to inflation with air or liquid perfluorocarbo...

journal_title：Magnetic resonance in medicine

authors： Rosen Y,Bloch BN,Lenkinski RE,Greenman RL,Marquis RP,Rofsky NM

更新日期：2007-05-01 00:00:00

abstract：:MRI evaluations of intramyocardial hemorrhage in acute infarction have relied on T(2) and T(2)(*) shortening only. We propose a more comprehensive evaluation of hemorrhagic infarction based on the concept that fluctuations in T(2) and T(1) relaxation in acute reperfused infarction will reflect transient edema and hemo...

journal_title：Magnetic resonance in medicine

authors： Foltz WD,Yang Y,Graham JJ,Detsky JS,Wright GA,Dick AJ

更新日期：2006-12-01 00:00:00

abstract：PURPOSE:To present a new method that can simultaneously and efficiently measure T1 and B1 (+) maps using reference region variable flip angle (RR-VFA) imaging. METHODS:Assuming T1 relaxation time in a reference region such as fat is well characterized, and the reference region sufficiently covers smoothly varying B1 (...

journal_title：Magnetic resonance in medicine

authors： Sung K,Saranathan M,Daniel BL,Hargreaves BA

更新日期：2013-10-01 00:00:00

abstract：:Cortical bone in the mature skeleton has a short T(2)* and produces no detectable signal with conventional MR sequences. A two-dimensional ultrashort echo time (UTE) sequence employing half radio frequency (RF) pulse excitations and radial ramp sampling reduces the effective TE to 8 micros and is capable of detecting ...

journal_title：Magnetic resonance in medicine

authors： Du J,Hamilton G,Takahashi A,Bydder M,Chung CB

更新日期：2007-11-01 00:00:00

abstract：PURPOSE:Multi-echo spin-echo (MSE) transverse relaxometry mapping using multi-component models is used to study disease activity in neuromuscular disease by assessing the T2 of the myocytic component (T2water ). Current extended phase graph algorithms are not optimized for fat fractions above 50% and the effects of ina...

journal_title：Magnetic resonance in medicine

authors： Keene KR,Beenakker JM,Hooijmans MT,Naarding KJ,Niks EH,Otto LAM,van der Pol WL,Tannemaat MR,Kan HE,Froeling M

更新日期：2020-11-01 00:00:00

abstract：:Temperature estimation in proton resonance frequency (PRF) shift MR thermometry requires a reference, or pretreatment, phase image that is subtracted from image phase during thermal treatment to yield a phase difference image proportional to temperature change. Referenceless thermometry methods derive a reference phas...

journal_title：Magnetic resonance in medicine

authors： Grissom WA,Lustig M,Holbrook AB,Rieke V,Pauly JM,Butts-Pauly K

更新日期：2010-10-01 00:00:00

abstract：:The goal of this work was to develop an MRI method for mapping the clearance of interstitial macromolecular plasma proteins after their extravasation from permeable blood vessels. To that end, a well-defined window of exposure to elevated blood levels was generated by inducing rapid clearance of macromolecular contras...

journal_title：Magnetic resonance in medicine

authors： Dafni H,Gilead A,Nevo N,Eilam R,Harmelin A,Neeman M

更新日期：2003-11-01 00:00:00

abstract：PURPOSE:Magnetic susceptibility is a physical property of matter that varies depending on chemical composition and abundance of different molecular species. Interest is growing in mapping of magnetic susceptibility in the human brain using magnetic resonance imaging techniques, but the influences affecting the mapped v...

journal_title：Magnetic resonance in medicine

authors： Sood S,Urriola J,Reutens D,O'Brien K,Bollmann S,Barth M,Vegh V

更新日期：2017-05-01 00:00:00

abstract：:A new NMR imaging technique, aiming at a reduction of the data acquisition time, is described in detail. The method is applicable in all multidimensional imaging situations where at least one spatial coordinate is resolved. Discussed at some length are the point-spread function, the required bandwidth of the NMR spect...

journal_title：Magnetic resonance in medicine

authors： van Uijen CM,den Boef JH,Verschuren FJ

更新日期：1985-06-01 00:00:00

abstract：PURPOSE:Spectrally selective "prewinding" radiofrequency pulses can counteract B0 inhomogeneity in steady-state sequences, but can only prephase a limited range of off-resonance. We propose spectral-spatial small-tip angle prewinding pulses that increase the off-resonance bandwidth that can be successfully prephased by...

journal_title：Magnetic resonance in medicine

authors： Williams SN,Nielsen JF,Fessler JA,Noll DC

更新日期：2018-03-01 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：PURPOSE:Conventional 31 P chemical shift imaging is time-consuming and yields only limited spatial resolution. The purpose of this study was to demonstrate feasibility of 31 P echo-planar spectroscopic imaging (EPSI) in vivo at 7T. METHODS:A 3D 31 P EPSI sequence with trapezoidal-shaped gradient pulses was implemented...

journal_title：Magnetic resonance in medicine

authors： Korzowski A,Bachert P

更新日期：2018-03-01 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：: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:Quantitative susceptibility mapping can be performed through the minimization of a function consisting of data fidelity and regularization terms. For data consistency, a Gaussian-phase noise distribution is often assumed, which breaks down when the signal-to-noise ratio is low. A previously proposed alternative...

journal_title：Magnetic resonance in medicine

authors： Milovic C,Bilgic B,Zhao B,Acosta-Cabronero J,Tejos C

更新日期：2018-08-01 00:00:00

abstract：:Partially parallel imaging strategies such as SMASH, SENSE, and PILS rely on the sensitivity distribution of phased array RF coils to reduce MRI imaging time. Using an N-element phased array, these techniques allow maximum accelerations, L, such that L < or = N, with acceleration defined as the factor by which scan ti...

journal_title：Magnetic resonance in medicine

authors： Bankson JA,Wright SM

更新日期：2002-04-01 00:00:00

abstract：:Subject motion during brain magnetic resonance spectroscopy acquisitions generally reduces the magnetic field (B₀) homogeneity across the volume of interest or voxel. This is the case even if prospective motion correction ensures that the voxel follows the head. We introduce a novel method for rapidly mapping linear v...

journal_title：Magnetic resonance in medicine

authors： Keating B,Ernst T

更新日期：2012-11-01 00:00:00

abstract：:1H MR spectra were recorded from human gastrocnemius muscle at 63.86 MHz using the body coil of the Signa scanner as transmitter and a 3-in. surface coil as receiver. The fat content of the muscle was quantified relative to that of water in a selected volume or slice. The fat/water ratio was 0.05-0.07 for normal muscl...

journal_title：Magnetic resonance in medicine

authors： Bárány M,Venkatasubramanian PN,Mok E,Siegel IM,Abraham E,Wycliffe ND,Mafee MF

更新日期：1989-05-01 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：:The acquisition of complete three-dimensional (3D), segmented gradient-echo data sets to visualize the coronary arteries can be both time consuming and sensitive to motion, even with use of multiple breath-holding or respiratory gating. An alternate hybrid approach is demonstrated here, in which real-time interactive ...

journal_title：Magnetic resonance in medicine

authors： Hardy CJ,Darrow RD,Pauly JM,Kerr AB,Dumoulin CL,Hu BS,Martin KM

更新日期：1998-07-01 00:00:00

abstract：:T1 is often ill-determined. This means that an Ernst angle excitation often cannot be precisely defined for the simple pulse and acquire experiment. Here, published 31P T1 values of metabolites in human muscle, liver, heart, and brain are archived, some new data on heart and brain added, and overall confidence interva...

journal_title：Magnetic resonance in medicine

authors： Bottomley PA,Ouwerkerk R

更新日期：1994-07-01 00:00:00

abstract：:Intrascan subject movement in clinical MR spectroscopic examinations may result in inconsistent water suppression that distorts the metabolite signals, frame-to-frame variations in spectral phase and frequency, and consequent reductions in the signal-to-noise ratio due to destructive averaging. Frame-to-frame phase/fr...

journal_title：Magnetic resonance in medicine

authors： Lin JM,Tsai SY,Liu HS,Chung HW,Mulkern RV,Cheng CM,Yeh TC,Chen NK

更新日期：2009-12-01 00:00:00

abstract：:This study determines the accuracy and feasibility of using localized spin-lattice (T1) relaxation time measurements from magnetic resonance (MR) images to follow changes in extracellular/intracellular fluid ratios in defined subvolumes of living tissue. A red blood cell suspension was used as a test system and a simp...

journal_title：Magnetic resonance in medicine

authors： Martin MA,Tatton WG,Lemaire C,Armstrong RL

更新日期：1990-07-01 00:00:00

abstract：:Slowly cycling cells are believed to play a critical role in tumor progression and metastatic dissemination. The goal of this study was to develop a method for in vivo detection of slowly cycling cells. To distinguish these cells from more rapidly proliferating cells that constitute the vast majority of cells in tumor...

journal_title：Magnetic resonance in medicine

authors： Magnitsky S,Roesch A,Herlyn M,Glickson JD

更新日期：2011-11-01 00:00:00