Analysis of phospholipid molecular species in brain by (31)P NMR spectroscopy.

abstract：:Gradient-echo EPI, blood oxygenation level-dependent (BOLD) functional MRI (fMRI) using parallel imaging (PI) is demonstrated at 7 Tesla with 16 channels, a fourfold 1D reduction factor (R), and fourfold maximal aliasing. The resultant activation detection in finger-tapping fMRI studies was robust, in full agreement w...

journal_title：Magnetic resonance in medicine

authors： Moeller S,Van de Moortele PF,Goerke U,Adriany G,Ugurbil K

更新日期：2006-07-01 00:00:00

abstract：:Partial-volume effects (PVE) in stroke imaging could hinder proper delineation of normal, ischemic, and at-risk tissues. Cerebral-blood-flow (CBF) and apparent diffusion coefficient (ADC) were measured at high and low resolution (HR = 128 x 128, LR = 64 x 64) in focal ischemia in rats during the acute phase. The data ...

journal_title：Magnetic resonance in medicine

authors： Ren H,Shen Q,Bardutzky J,Fisher M,Duong TQ

更新日期：2004-12-01 00:00:00

abstract：:The application of spectroscopy techniques to the study of normal and pathological tissue is currently limited by the difficulties of acquiring precisely localized spectra and analyzing the resulting, relatively low signal-to-noise data. Interpretation of multivoxel spectroscopy data is greatly facilitated by estimati...

journal_title：Magnetic resonance in medicine

authors： Nelson SJ,Vigneron DB,Brown TR

更新日期：1992-05-01 00:00:00

abstract：:Previous theoretical reports described the dependence of interpretation of the observed phase of the NMR signal on the time origin(s) of moment calculations and position's Taylor series expansion. This work provides experimental confirmation of predictions derived from that theory. For accelerative motion, experimenta...

journal_title：Magnetic resonance in medicine

authors： Duerk JL,Simonetti OP,Hurst GC,Finelli DA

更新日期：1994-07-01 00:00:00

abstract：PURPOSE:To present and validate a new method that formalizes a direct link between k-space and wavelet domains to apply separate undersampling and reconstruction for high- and low-spatial-frequency k-space data. THEORY AND METHODS:High- and low-spatial-frequency regions are defined in k-space based on the separation o...

journal_title：Magnetic resonance in medicine

authors： Sung K,Hargreaves BA

更新日期：2013-11-01 00:00:00

abstract：PURPOSE:To determine whether neurochemical concentrations obtained at two MRI sites using clinical 3T scanners can be pooled when a highly optimized, nonvendor short-echo, single-voxel proton MRS pulse sequence is used in conjunction with identical calibration and quantification procedures. METHODS:A modified semi-LAS...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Adanyeguh IM,Emir UE,Nguyen TM,Valabregue R,Henry PG,Mochel F,Öz G

更新日期：2015-05-01 00:00:00

abstract：:Current MRI methods for myocardial motion and strain quantification have limited resolution because of Fourier space spectral peak interference. Methods have been proposed to remove this interference in order to improve resolution; however, these methods are clinically impractical due to the prolonged imaging times. I...

journal_title：Magnetic resonance in medicine

authors： Agarwal HK,Prince JL,Abd-Elmoniem KZ

更新日期：2010-08-01 00:00:00

abstract：PURPOSE:To compare experimental transverse relaxivities of iron oxide nanocrystals (IONC) as a function of clustering and magnetic field strength with different theoretical model predictions. THEORY AND METHODS:Well-defined IONC clusters in nanoemulsions (NEs) of which both size and IONC loading could be judiciously t...

journal_title：Magnetic resonance in medicine

authors： Hak S,Goa PE,Stenmark S,Bjerkholt FF,Haraldseth O

更新日期：2015-09-01 00:00:00

abstract：:The purpose of this study is (1) to determine the correlation between T(1rho) and T(2) and degenerative grade in intervertebral discs using in vivo 3.0-T MRI, and (2) to determine the association between T(1rho) and T(2) and clinical findings as quantified by the SF-36 Questionnaire and Oswestry Disability Index. Sixt...

journal_title：Magnetic resonance in medicine

authors： Blumenkrantz G,Zuo J,Li X,Kornak J,Link TM,Majumdar S

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:At high field, T2 -weighted (T2 w) imaging is limited by transmit field inhomogeneity and increased radiofrequency power deposition. In this work, we introduce SAMPA (Slice-selective Adiabatic Magnetization T2 PrepAration) and demonstrate its use for efficient brain T2 w imaging at 7 Tesla (T). METHODS:SAMPA w...

journal_title：Magnetic resonance in medicine

authors： Dyvorne H,Balchandani P

更新日期：2016-12-01 00:00:00

abstract：:Magnetic resonance (MR) imaging and relaxation time measurements of bioresorbable implants made of polylactic acid (PLA), as well as the surrounding tissues, were carried out over a period of 6 months to monitor the implant state and the body's responses, and to determine how these processes are reflected in MR data. ...

journal_title：Magnetic resonance in medicine

authors： Stroman PW,Dorvil JC,Marois Y,Poddevin N,Guidoin R

更新日期：1999-07-01 00:00:00

abstract：:Dual labeled liposomes, carrying both paramagnetic and fluorescent lipids, were recently proposed as potent contrast agents for MR molecular imaging. These nanoparticles are coated with poly(ethylene glycol) (PEG) to increase their blood circulation half-life, which should allow extensive accumulation at the targeted ...

journal_title：Magnetic resonance in medicine

authors： van Tilborg GA,Strijkers GJ,Pouget EM,Reutelingsperger CP,Sommerdijk NA,Nicolay K,Mulder WJ

更新日期：2008-12-01 00:00:00

abstract：PURPOSE:To develop a method for retrospective artifact elimination of MRS data. This retrospective method was based on an approach that combines jackknife analyses with the correlation of spectral windows, and therefore termed "JKC." METHODS:Twelve healthy volunteers performed 3 separate measurement protocols using a ...

journal_title：Magnetic resonance in medicine

authors： Tapper S,Tisell A,Helms G,Lundberg P

更新日期：2019-04-01 00:00:00

abstract：:Maximal intensity projection (MIP) is routinely used to view MRA and other volumetric angiographic data. The straightforward implementation of MIP is ray casting that traces a volumetric data set in a computationally expensive manner. This article reports a fast MIP algorithm using shear warp factorization and reduced...

journal_title：Magnetic resonance in medicine

authors： Fang L,Wang Y,Qiu B,Qian Y

更新日期：2002-04-01 00:00:00

abstract：:A method is described for multislice imaging by means of rf pulses which contain a multifrequency excitation spectrum. These pulses label each slice by an individual signal phase and allow the separation of the signals from all the slices by subsequent add/subtract procedures. The image sensitivity corresponds to the ...

journal_title：Magnetic resonance in medicine

authors： Müller S

更新日期：1988-03-01 00:00:00

abstract：:The image intensity in magnetic resonance magnitude images in the presence of noise is shown to be governed by a Rician distribution. Low signal intensities (SNR < 2) are therefore biased due to the noise. It is shown how the underlying noise can be estimated from the images and a simple correction scheme is provided ...

journal_title：Magnetic resonance in medicine

authors： Gudbjartsson H,Patz S

更新日期：1995-12-01 00:00:00

abstract：:In the dynamic nuclear polarization process, microwave irradiation facilitates exchange of polarization from a radical's unpaired electron to nuclear spins at cryogenic temperatures, increasing polarization by >10,000. Doping samples with Gd(3+) ions further increases the achievable solid-state polarization. However, ...

journal_title：Magnetic resonance in medicine

authors： Gordon JW,Fain SB,Rowland IJ

更新日期：2012-12-01 00:00:00

abstract：:Genetically engineered mouse models provide enormous potential for investigation of the underlying mechanisms of atherosclerotic disease, but noninvasive imaging methods for analysis of atherosclerosis in mice are currently limited. This study aimed to demonstrate the feasibility of MRI to noninvasively visualize athe...

journal_title：Magnetic resonance in medicine

authors： Wiesmann F,Szimtenings M,Frydrychowicz A,Illinger R,Hunecke A,Rommel E,Neubauer S,Haase A

更新日期：2003-07-01 00:00:00

abstract：PURPOSE:We report a series of techniques to reliably eliminate artifacts in interleaved echo-planar imaging (EPI) based diffusion-weighted imaging (DWI). METHODS:First, we integrate the previously reported multiplexed sensitivity encoding (MUSE) algorithm with a new adaptive Homodyne partial-Fourier reconstruction alg...

journal_title：Magnetic resonance in medicine

authors： Chang HC,Guhaniyogi S,Chen NK

更新日期：2015-05-01 00:00:00

abstract：PURPOSE:Applications of dynamic shimming require high field fidelity, and characterizing the shim field dynamics is therefore necessary. Modeling the system as linear and time-invariant, the purpose of this work was to measure the impulse response function with optimal sensitivity. THEORY AND METHODS:Frequency-swept p...

journal_title：Magnetic resonance in medicine

authors： Vannesjo SJ,Dietrich BE,Pavan M,Brunner DO,Wilm BJ,Barmet C,Pruessmann KP

更新日期：2014-08-01 00:00:00

abstract：:In numerical analyses of radiofrequency (RF) fields for MRI, RF power is often permitted to radiate out of the problem region. In reality, RF power will be confined by the magnet bore and RF screen enclosing the magnet room. We present numerical calculations at different frequencies for various surface and volume coil...

journal_title：Magnetic resonance in medicine

authors： Liu W,Kao CP,Collins CM,Smith MB,Yang QX

更新日期：2013-01-01 00:00:00

abstract：:Conventional approaches for MR elastography (MRE) using surface drivers have difficulty achieving sufficient shear wave propagation in the prostate gland due to attenuation. In this study we evaluate the feasibility of generating shear wave propagation in the prostate gland using a transurethral device. A novel transu...

journal_title：Magnetic resonance in medicine

authors： Chopra R,Arani A,Huang Y,Musquera M,Wachsmuth J,Bronskill M,Plewes D

更新日期：2009-09-01 00:00:00

abstract：PURPOSE:To develop and test real-time MR elastography for viscoelastic parameter quantification in skeletal muscle during dynamic exercises. METHODS:In 15 healthy participants, 6 groups of lower-leg muscles (tibialis anterior, tibialis posterior, peroneus, extensor digitorum longus, soleus, gastrocnemius) were investi...

journal_title：Magnetic resonance in medicine

authors： Schrank F,Warmuth C,Görner S,Meyer T,Tzschätzsch H,Guo J,Uca YO,Elgeti T,Braun J,Sack I

更新日期：2020-07-01 00:00:00

abstract：:Double wave vector diffusion weighting uses gradients along two different directions between excitation and acquisition. It has been shown theoretically that for restricted diffusion the signal amplitude in such an experiment can depend on the angle between the two gradient vectors. The highest amplitude is obtained w...

journal_title：Magnetic resonance in medicine

authors： Koch MA,Finsterbusch J

更新日期：2008-07-01 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：:A robust postprocessing method to detect regions of magnetic field change is presented. High resolution gradient echo data is acquired to create a complex baseline image. From this image, two low resolution images are obtained by applying a low pass filter on the magnitude image and the complex image, respectively. Su...

journal_title：Magnetic resonance in medicine

authors： Lai S,Reichenbach JR,Haacke EM

更新日期：1996-11-01 00:00:00

abstract：PURPOSE:In conventional three-dimensional magnetic resonance elastography, motion encoding gradients (MEGs) synchronized to a mechanical excitation are applied separately in each direction to encode tissue displacement generated by the corresponding waves. This requires long acquisition times that introduce errors due ...

journal_title：Magnetic resonance in medicine

authors： Nir G,Sahebjavaher RS,Sinkus R,Salcudean SE

更新日期：2015-04-01 00:00:00

abstract：PURPOSE:The primary purpose of this study is to propose a method for the simultaneous quantitative three-dimensional (3D) mapping of conductivity and susceptibility using double-echo ultrashort echo time (UTE) imaging. The secondary purpose is to investigate the changes of these properties over time during in vitro hem...

journal_title：Magnetic resonance in medicine

authors： Gho SM,Shin J,Kim MO,Kim DH

更新日期：2016-07-01 00:00:00

abstract：:The shells trajectory is a 3D data acquisition method with improved efficiency compared to Cartesian sampling. It is a true center-out trajectory that does not repeatedly resample the center of k-space, and also offers advantages for motion correction. This work demonstrates that k-space undersampling can be combined ...

journal_title：Magnetic resonance in medicine

authors： Shu Y,Riederer SJ,Bernstein MA

更新日期：2006-09-01 00:00:00

abstract：:The aim of this study was to detect salvageable peri-infarction myocardium by MRI in rats after infarction, using with a double contrast agent (CA) protocol at 7 Tesla. Intravascular superparamagnetic iron oxide (SPIO) nanoparticles and an extracellular paramagnetic CA (Gd-DOTA) were used to characterize the peri-infa...

journal_title：Magnetic resonance in medicine

authors： Chapon C,Lemaire L,Franconi F,Marescaux L,Legras P,Denizot B,Le Jeune JJ

更新日期：2004-10-01 00:00:00