Fast, pseudo-continuous arterial spin labeling for functional imaging using a two-coil system.

abstract：:Head motion is a fundamental problem in functional magnetic resonance imaging and is often a limiting factor in its clinical implementation. This work presents a rigid-body motion correction strategy for echo-planar imaging sequences that uses micro radiofrequency coil "active markers" for real-time, slice-by-slice pr...

journal_title：Magnetic resonance in medicine

authors： Ooi MB,Krueger S,Muraskin J,Thomas WJ,Brown TR

更新日期：2011-07-01 00:00:00

abstract：:K1 (first-order transfer constant from arterial plasma to myocardium for Gd-DTPA) and Vd (distribution volume of Gd-DTPA in myocardium) were measured in vivo in a canine model (n = 5) using MRI-derived myocardial perfusion curves and a compartmental model. Perfusion curves were obtained after a bolus injection of Gd-D...

journal_title：Magnetic resonance in medicine

authors： Vallée JP,Sostman HD,MacFall JR,Wheeler T,Hedlund LW,Spritzer CE,Coleman RE

更新日期：1997-12-01 00:00:00

abstract：:An array of 33 prototype polypeptides was examined as putative contrast agents that can be distinguished from each other based on the chemical exchange saturation transfer (CEST) mechanism. These peptides were chosen based on predictions of the chemical exchange rates of exchangeable amide, amine, and hydroxyl protons...

journal_title：Magnetic resonance in medicine

authors： McMahon MT,Gilad AA,DeLiso MA,Berman SM,Bulte JW,van Zijl PC

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:To investigate previously unreported effects of signal drift as a result of temporal scanner instability on diffusion MRI data analysis and to propose a method to correct this signal drift. METHODS:We investigated the signal magnitude of non-diffusion-weighted EPI volumes in a series of diffusion-weighted imag...

journal_title：Magnetic resonance in medicine

authors： Vos SB,Tax CM,Luijten PR,Ourselin S,Leemans A,Froeling M

更新日期：2017-01-01 00:00:00

abstract：:We used high-field (13)C NMR (18.8 T) to assign unambiguously the isotopic shifts induced by the deuterium substitutions of the H3(proR) and H3(proS) hydrogens of (2-(13)C) glutamate in extracts of the brain from deuterated animals. Monodeuterated H3R or H3S glutamate diastereoisomers were produced stereospecifically ...

journal_title：Magnetic resonance in medicine

authors： Rodrigues TB,Violante IR,Cerdán S

更新日期：2010-04-01 00:00:00

abstract：:It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...

journal_title：Magnetic resonance in medicine

authors： Alsop DC

更新日期：1997-02-01 00:00:00

abstract：:Proton T2 relaxation and its biexponential components have been determined in rabbit skeletal muscle in the presence and absence of GdDTPA. The effect of GdDTPA, which distributes only in the extracellular space, was greatest in the longer-relaxing T2 component (T22). A 27% reduction in T22 was measured for slow-twitc...

journal_title：Magnetic resonance in medicine

authors： Adzamli IK,Jolesz FA,Bleier AR,Mulkern RV,Sandor T

更新日期：1989-08-01 00:00:00

abstract：PURPOSE:The goal of this study is to characterize and improve the accuracy of 2D magnetic resonance fingerprinting (MRF) scans in the presence of slice profile (SP) and B1 imperfections, which are two main factors that affect quantitative results in MRF. METHODS:The SP and B1 imperfections are characterized and correc...

journal_title：Magnetic resonance in medicine

authors： Ma D,Coppo S,Chen Y,McGivney DF,Jiang Y,Pahwa S,Gulani V,Griswold MA

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:To design hyperbolic secant (HS) excitation pulses to reduce signal dropout in the orbitofrontal and inferior temporal regions in gradient-echo echo-planar imaging (GE-EPI) for functional MRI (fMRI) applications. METHODS:An algorithm based on Bloch simulations optimizes the HS pulse parameters needed to give t...

journal_title：Magnetic resonance in medicine

authors： Wastling SJ,Barker GJ

更新日期：2015-09-01 00:00:00

abstract：:A demonstration of MR guided thermal surgery involved experiments with imaging of focused ultrasound in an MRI system, measurements of the thermal transients and a thermal analysis of the resulting images. Both the heat distribution and the creation of focused ultrasound lesions in gel phantoms, in vitro bovine muscle...

journal_title：Magnetic resonance in medicine

authors： Cline HE,Schenck JF,Watkins RD,Hynynen K,Jolesz FA

更新日期：1993-07-01 00:00:00

abstract：PURPOSE:To separate the spectrally overlapped lactate and lipid signals at 1.3 ppm using diffusion-weighted magnetic resonance spectroscopy (DW-MRS) based on their large diffusivity difference. METHODS:DW-MRS was applied to the gel phantoms containing lactate and lipid droplets, and to the rat brain tumors. Lactate an...

journal_title：Magnetic resonance in medicine

authors： Wang AM,Leung GK,Kiang KM,Chan D,Cao P,Wu EX

更新日期：2017-02-01 00:00:00

abstract：PURPOSE:T2 -weighted sequences are particularly sensitive to the radiofrequency (RF) field inhomogeneity problem at ultra-high-field because of the errors accumulated by the imperfections of the train of refocusing pulses. As parallel transmission (pTx) has proved particularly useful to counteract RF heterogeneities, u...

journal_title：Magnetic resonance in medicine

authors： Gras V,Mauconduit F,Vignaud A,Amadon A,Le Bihan D,Stöcker T,Boulant N

更新日期：2018-07-01 00:00:00

abstract：:This study demonstrates the feasibility of applying free-breathing, cardiac-gated, susceptibility-weighted fast spin-echo imaging together with black blood preparation and navigator-gated respiratory motion compensation for anatomically accurate T2* mapping of the heart. First, T2* maps are presented for oil phantoms ...

journal_title：Magnetic resonance in medicine

authors： Heinrichs U,Utting JF,Frauenrath T,Hezel F,Krombach GA,Hodenius MA,Kozerke S,Niendorf T

更新日期：2009-09-01 00:00:00

abstract：PURPOSE:To develop and evaluate a novel two-dimensional self-gated imaging technique for free-breathing cardiac cine MRI that is free of motion-detection overhead and requires minimal planning for motion tracking. METHODS:Motion along the readout direction was extracted solely from normal Cartesian imaging readouts ne...

journal_title：Magnetic resonance in medicine

authors： Guo L,Derbyshire JA,Herzka DA

更新日期：2016-08-01 00:00:00

abstract：:The accurate assessment of pulmonary perfusion is especially important in the evaluation of patients with suspected pulmonary embolism, a common and potentially lethal disorder that can be treated by aggressive anticoagulation. In this study, we demonstrate for the first time the use of MR to image pulmonary perfusion...

journal_title：Magnetic resonance in medicine

authors： Hatabu H,Gaa J,Kim D,Li W,Prasad PV,Edelman RR

更新日期：1996-10-01 00:00:00

abstract：:The course of pulmonary edema formation after an intratracheal (i.t.) instillation of ovalbumin was followed noninvasively by magnetic resonance imaging (MRI) in actively sensitized Brown Norway (BN) rats. Changes in edema volume assessed by MRI mimicked the results from the analysis of the number and activation of in...

journal_title：Magnetic resonance in medicine

authors： Beckmann N,Tigani B,Ekatodramis D,Borer R,Mazzoni L,Fozard JR

更新日期：2001-01-01 00:00:00

abstract：:In this study, a spin- and gradient-echo echo-planar imaging (SAGE EPI) MRI pulse sequence is presented that allows simultaneous measurements of gradient-echo and spin-echo dynamic susceptibility-contrast perfusion-weighted imaging data. Following signal excitation, five readout trains were acquired using spin- and gr...

journal_title：Magnetic resonance in medicine

authors： Schmiedeskamp H,Straka M,Newbould RD,Zaharchuk G,Andre JB,Olivot JM,Moseley ME,Albers GW,Bammer R

更新日期：2012-07-01 00:00:00

abstract：PURPOSE:Accurate characterization of contrast reagent (CR) longitudinal relaxivity in whole blood is required to predict arterial signal intensity in contrast-enhanced MR angiography (CE-MRA). This study measured the longitudinal relaxation rate constants (R1 ) over a concentration range for non-protein-binding and pro...

journal_title：Magnetic resonance in medicine

authors： Wilson GJ,Woods M,Springer CS Jr,Bastawrous S,Bhargava P,Maki JH

更新日期：2014-12-01 00:00:00

abstract：:Rapid MR imaging using the stimulated echo acquisition mode (STEAM) technique yields single-shot images without any sensitivity to resonance offset effects. However, the absence of susceptibility-induced signal voids or geometric distortions is at the expense of a somewhat lower signal-to-noise ratio than EPI. As a co...

journal_title：Magnetic resonance in medicine

authors： Block KT,Frahm J

更新日期：2008-04-01 00:00:00

abstract：:This study investigated the use of dynamic, volumetric MRI to measure 3D skeletal motion. Ten healthy subjects were positioned on a MR-compatible knee loading device and instructed to harmonically flex and extend their knee at 0.5 Hz. The device induced active quadriceps loading with knee flexion, similar to the load ...

journal_title：Magnetic resonance in medicine

authors： Kaiser J,Bradford R,Johnson K,Wieben O,Thelen DG

更新日期：2013-05-01 00:00:00

abstract：PURPOSE:Imaging gradients result in the generation of concomitant fields, or Maxwell fields, which are of increasing importance at higher gradient amplitudes. These time-varying fields cause additional phase accumulation, which must be compensated for to avoid image artifacts. In the case of gradient systems employing ...

journal_title：Magnetic resonance in medicine

authors： Weavers PT,Tao S,Trzasko JD,Frigo LM,Shu Y,Frick MA,Lee SK,Foo TK,Bernstein MA

更新日期：2018-03-01 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 investigate the influence of transcytolemmal water exchange on estimates of tissue microstructural parameters derived from diffusion MRI using conventional PGSE and IMPULSED methods. METHODS:Computer simulations were performed to incorporate a broad range of intracellular water life times τin (50-∞ ms), cel...

journal_title：Magnetic resonance in medicine

authors： Li H,Jiang X,Xie J,Gore JC,Xu J

更新日期：2017-06-01 00:00:00

abstract：:The goal of this work was to develop and evaluate a numerically optimized inversion pulse to be used with a homonuclear editing sequence to measure human cerebral GABA in vivo at 4.1 T in the occipital lobe. The optimized pulse was constructed using pallindromic symmetry with 30 pulses and 29 delays. The optimized pul...

journal_title：Magnetic resonance in medicine

authors： Hetherington HP,Newcomer BR,Pan JW

更新日期：1998-01-01 00:00:00

abstract：:The equal-phase line (EPL) algorithm is proposed as a means of allowing rapid Fourier transform (FT) reconstruction of MR image data acquired on a non-Cartesian grid. The pixels on the image are grouped according to their positions. The pixels in a group have the same phase in the complex exponential function -exp[j2p...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Lin J,Jin D

更新日期：2002-06-01 00:00:00

abstract：PURPOSE:To demonstrate how triple diffusion encoding (TDE) MRI can be applied to separately estimate the intra-axonal and extra-axonal diffusion tensors in white matter (WM). METHODS:Using a TDE pulse sequence with an axially symmetric b-matrix, diffusion MRI data were acquired at 3T for 3 healthy adults with an axial...

journal_title：Magnetic resonance in medicine

authors： Ramanna S,Moss HG,McKinnon ET,Yacoub E,Helpern JA,Jensen JH

更新日期：2020-06-01 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：:The potential of quantitative parameter images of the relaxation times T1 and T2, the proton density rho and the apparent diffusion coefficient (ADC) to characterize three different experimental rat brain tumors (F98 glioma, RN6 Schwannoma, and E376 neuroblastoma) was studied. All parameter values, as determined in hi...

journal_title：Magnetic resonance in medicine

authors： Eis M,Els T,Hoehn-Berlage M

更新日期：1995-12-01 00:00:00

abstract：:Aggregation of human erythrocytes at physiological hematocrit by hydroxyethyl starch (HES) was investigated with a 1H nuclear magnetic resonance method which measures the erythrocyte mean water exchange time, tau a. A relationship that takes into account the effect of the aggregate as the water-exchanging unit was use...

journal_title：Magnetic resonance in medicine

authors： Caines GH,Goldstein JH

更新日期：1987-07-01 00:00:00

abstract：:The suppression of water signals in in vivo proton spectra by means of multiple-quantum filtering can be brought about in several ways. This communication exposes the shortcomings of using purely subtractive filtering techniques to observe signals from metabolites that contain proton couplings of the form AX3. ...

journal_title：Magnetic resonance in medicine

authors： Nosel W,Trimble LA,Shen JF,Allen PS

更新日期：1989-09-01 00:00:00