Image reconstruction using a gradient impulse response model for trajectory prediction.

abstract：PURPOSE:To develop and evaluate a neural network-based method for Gibbs artifact and noise removal. METHODS:A convolutional neural network (CNN) was designed for artifact removal in diffusion-weighted imaging data. Two implementations were considered: one for magnitude images and one for complex images. Both models we...

journal_title：Magnetic resonance in medicine

authors： Muckley MJ,Ades-Aron B,Papaioannou A,Lemberskiy G,Solomon E,Lui YW,Sodickson DK,Fieremans E,Novikov DS,Knoll F

更新日期：2021-01-01 00:00:00

abstract：:A method is demonstrated for detection of magnetization from a selected region within the sensitive volume of a surface coil in a single acquisition. Composite pulses are described which eliminate signals from regions where magnetization is rotated 270 and 450 degrees. There is a loss of 1.3% or less of signal from re...

journal_title：Magnetic resonance in medicine

authors： Karczmar GS,Matson GB,Weiner MW

更新日期：1986-04-01 00:00:00

abstract：:Manipulation of the data describing two-dimensional magnetic resonance (MR) images can be used to zoom an image, decrease image noise and artifacts by modeling, or emphasize object edges in the field of view. In this paper, a two-dimensional band-selectable digital filtering (2D-BSDF) technique is detailed. This can b...

journal_title：Magnetic resonance in medicine

authors： Mitchell DK,Nichols ST,Smith MR,Scott K

更新日期：1989-03-01 00:00:00

abstract：:Diffusion-weighted single voxel experiments conducted at b-values up to 1 x 10(4) smm-2 yielded biexponential signal attenuation curves for both normal and ischemic brain. The relative fractions of the rapidly and slowly decaying components (f1, f2) are f1 = 0.80 +/- 0.02, f2 = 0.17 +/- 0.02 in healthy adult rat brain...

journal_title：Magnetic resonance in medicine

authors： Niendorf T,Dijkhuizen RM,Norris DG,van Lookeren Campagne M,Nicolay K

更新日期：1996-12-01 00:00:00

abstract：:Developing a method to noninvasively monitor tissue-engineered constructs is critical for the optimization of construct design and for assessing therapeutic efficacy. For this purpose, NMR is a powerful technique that can be used to obtain both images and spectroscopic data. But the inherent sensitivity of NMR limits ...

journal_title：Magnetic resonance in medicine

authors： Volland NA,Mareci TH,Constantinidis I,Simpson NE

更新日期：2010-04-01 00:00:00

abstract：:To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/...

journal_title：Magnetic resonance in medicine

authors： van der Toorn A,Syková E,Dijkhuizen RM,Vorísek I,Vargová L,Skobisová E,van Lookeren Campagne M,Reese T,Nicolay K

更新日期：1996-07-01 00:00:00

abstract：:The assumption of linear time-invariance (LTI) in the human primary somatosensory cortex (SI) is assessed for fMRI signals generated by variable-duration vibrotactile stimuli. Predictions based on time-shifted summation (TSS) of responses to 2 s stimuli overestimate observed BOLD signal amplitudes in response to longe...

journal_title：Magnetic resonance in medicine

authors： Nangini C,Macintosh BJ,Tam F,Staines WR,Graham SJ

更新日期：2005-02-01 00:00:00

abstract：PURPOSE:To investigate a computationally efficient method for optimizing the Cramér-Rao Lower Bound (CRLB) of quantitative sequences without using approximations or an analytical expression of the signal. METHODS:Automatic differentiation was applied to Bloch simulations and used to optimize several quantitative seque...

journal_title：Magnetic resonance in medicine

authors： Lee PK,Watkins LE,Anderson TI,Buonincontri G,Hargreaves BA

更新日期：2019-10-01 00:00:00

abstract：:Proton spin relaxation rate constants in normal and hyponatremic rat brain were measured to determine the sensitivity of metabolite relaxation properties to cytotoxic edema and to quantify metabolite concentration in normal and edematous brain. Relaxation rate constants for protons of water and spectral regions with d...

journal_title：Magnetic resonance in medicine

authors： Rooney WD,Ebisu T,Mancuso A,Graham S,Weiner MW,Maudsley AA

更新日期：1996-05-01 00:00:00

abstract：:The radial trajectory has found applications in cardiac imaging because of its resilience to undersampling and motion artifacts. Recent work has shown that interleaved and weighted radial imaging can produce images with multiple contrasts from a single data set. This feature was investigated for inversion recovery ima...

journal_title：Magnetic resonance in medicine

authors： Peters DC,Botnar RM,Kissinger KV,Yeon SB,Appelbaum EA,Manning WJ

更新日期：2006-05-01 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：:Minimally invasive cardiac surgery requires arresting and emptying of the heart, which compromises visualization of the surgical field. In this feasibility study a novel surgical procedure is demonstrated in which real-time MRI is used to guide the placement of a prosthetic aortic valve in the beating heart via direct...

journal_title：Magnetic resonance in medicine

authors： McVeigh ER,Guttman MA,Lederman RJ,Li M,Kocaturk O,Hunt T,Kozlov S,Horvath KA

更新日期：2006-11-01 00:00:00

abstract：:In this study we utilized manganese-enhanced MRI (MEMRI) to evaluate the in vivo transneuronal efficiency of manganese ion (Mn(2+)) movement as a means to assess overall changes in neuronal function. We designated this extension the manganese transfer index (MTI) value. To evaluate the MTI value as an index of transne...

journal_title：Magnetic resonance in medicine

authors： Serrano F,Deshazer M,Smith KD,Ananta JS,Wilson LJ,Pautler RG

更新日期：2008-07-01 00:00:00

abstract：PURPOSE:To exploit the improved comparability and hardware independency of quantitative MRI, databases of MR physical parameters in healthy tissue are required, to which tissue properties of patients can be compared. In this work, normative values for longitudinal and transverse relaxation times in the brain were estab...

journal_title：Magnetic resonance in medicine

authors： Piredda GF,Hilbert T,Granziera C,Bonnier G,Meuli R,Molinari F,Thiran JP,Kober T

更新日期：2020-01-01 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：:Spiral k-space magnetic resonance spectroscopic imaging (MRSI) requires high performance from gradient hardware systems. During the readout phase, oscillating gradients are continuously played out, which can cause undesired effects. These effects on the quality of SI data are non-intuitive because of their time-varyin...

journal_title：Magnetic resonance in medicine

authors： Kim DH,Spielman DM

更新日期：2006-07-01 00:00:00

abstract：:Radial MRI sequences are frequently used to obtain images with reduced sensitivity to motion. To decrease imaging time, multiple spin-echo acquisitions can be incorporated into radial sequences. In this case, different radial lines of Fourier data have different TE times and the resulting images can contain streaking ...

journal_title：Magnetic resonance in medicine

authors： Theilmann RJ,Gmitro AF,Altbach MI,Trouard TP

更新日期：2004-04-01 00:00:00

abstract：:Chemical shift-based multipoint water-fat separation methods have been applied in balanced steady-state free precession (bSSFP) sequences because of the high signal-to-noise-ratio (SNR) attainable. In this approach the echo formation is approximated to occur concurrently for both water and fat at an echo time (TE) equ...

journal_title：Magnetic resonance in medicine

authors： Kim H,Pinus AB,Wang J,Murphy PS,Constable RT

更新日期：2007-08-01 00:00:00

abstract：PURPOSE:To develop a method that fits a multipool model to z-spectra acquired from non-steady state sequences, taking into account the effects of variations in T1 or B1 amplitude and the results estimating the parameters for a four-pool model to describe the z-spectrum from the healthy brain. METHODS:We compared measu...

journal_title：Magnetic resonance in medicine

authors： Geades N,Hunt BAE,Shah SM,Peters A,Mougin OE,Gowland PA

更新日期：2017-08-01 00:00:00

abstract：:For sodium imaging of the human brain, Gibbs' ringing can degrade image appearance and confound image analysis; k-space filtering is generally required. In this work, the signal to noise ratio (SNR) advantage of sampling density weighted apodization (SDWA) over uniform k-space sampling with postacquisition filtering a...

journal_title：Magnetic resonance in medicine

authors： Stobbe R,Beaulieu C

更新日期：2008-10-01 00:00:00

abstract：:Recovery of the cerebral cortex after 10 min of cardiac arrest was studied in rat using noninvasive MRI techniques. The apparent diffusion coefficient (ADC) of brain water was imaged to document reversal of the metabolic impairment. Perfusion-weighted imaging and blood oxygen level dependent (BOLD) imaging were perfor...

journal_title：Magnetic resonance in medicine

authors： Schmitz B,Bock C,Hoehn-Berlage M,Kerskens CM,Böttiger BW,Hossmann KA

更新日期：1998-05-01 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：:Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...

journal_title：Magnetic resonance in medicine

authors： Weisskoff RM

更新日期：1996-10-01 00:00:00

abstract：PURPOSE:To assess the blood-tissue distribution of hyperpolarized (13) C-labeled molecules in vivo. METHODS:Spin-echo experiments with simultaneous acquisition of the free induction decay (FID) signal following the excitation pulse and the spin-echo signal, were used to monitor hyperpolarized [1-(13) C]lactate, [1-(13...

journal_title：Magnetic resonance in medicine

authors： Kettunen MI,Kennedy BW,Hu DE,Brindle KM

更新日期：2013-11-01 00:00:00

abstract：:A double-echo two-excitation pulse sequence encoding fat and water signals for a phase-sensitive three-point Dixon-type analysis (DE-3PD) was developed and implemented on a 1.5 T MR imager. Data processing was performed using a previously developed two-dimensional (2D) region-growing algorithm, adapted to use double-e...

journal_title：Magnetic resonance in medicine

authors： Szumowski J,Coshow W,Li F,Coombs B,Quinn SF

更新日期：1995-07-01 00:00:00

abstract：:The assessment of myocardial fibrosis and extracellular volume requires accurate estimation of myocardial T1 s. While image acquisition using the modified Look-Locker inversion recovery technique is clinically feasible for myocardial T1 mapping, respiratory motion can limit its applicability. Moreover, the conventiona...

journal_title：Magnetic resonance in medicine

authors： Xue H,Greiser A,Zuehlsdorff S,Jolly MP,Guehring J,Arai AE,Kellman P

更新日期：2013-05-01 00:00:00

abstract：PURPOSE:In this work, 22 configurations for remote radiofrequency (RF) coil arrays consisting of different transmit element designs for 7 Tesla (T) ultrahigh-field MRI are compared by numerical simulations. METHODS:Investigated transmit RF element types are rectangular loops, micro striplines, micro striplines with me...

journal_title：Magnetic resonance in medicine

authors： Rietsch SHG,Orzada S,Bitz AK,Gratz M,Ladd ME,Quick HH

更新日期：2018-02-01 00:00:00

abstract：:The somatotopical organization of the human somatosensory cortex was analyzed with echo-planar imaging at 1.5 Tesla, utilizing deoxyhemoglobin as an endogenous contrast medium. Scrubbing stimulation at a frequency of 3 Hz was applied to one of three cutaneous areas: toes, fingertips, and tongue tip. Parasagittal echo-...

journal_title：Magnetic resonance in medicine

authors： Sakai K,Watanabe E,Onodera Y,Itagaki H,Yamamoto E,Koizumi H,Miyashita Y

更新日期：1995-05-01 00:00:00

abstract：PURPOSE:To remove nuisance signals (e.g., water and lipid signals) for (1) H MRSI data collected from the brain with limited and/or sparse (k, t)-space coverage. METHODS:A union-of-subspace model is proposed for removing nuisance signals. The model exploits the partial separability of both the nuisance signals and the...

journal_title：Magnetic resonance in medicine

authors： Ma C,Lam F,Johnson CL,Liang ZP

更新日期：2016-02-01 00:00:00

abstract：:The MMQ cell line is a unique prolactin-secreting rat pituitary cell line. MMQ cells entrapped in agarose gel threads are metabolically active, as determined by the uptake and phosphorylation of creatine and the maintenance of high energy phosphates for over 15 h. Forskolin activates the catalytic subunit of adenylyl ...

journal_title：Magnetic resonance in medicine

authors： Goger MJ,Login IS,Fernandez EJ,Grisham CM

更新日期：1994-11-01 00:00:00