Design of spectral-spatial phase prewinding pulses and their use in small-tip fast recovery steady-state imaging.

abstract：:Lower extremity peripheral vein bypass grafts (LE-PVBG) imaged with high-resolution black blood three-dimensional (3D) inner-volume (IV) fast spin echo (FSE) MRI at 1.5 Tesla possess a two-layer appearance in T1W images while only the inner layer appears visible in the corresponding T2W images. This study quantifies t...

journal_title：Magnetic resonance in medicine

authors： Mitsouras D,Owens CD,Conte MS,Ersoy H,Creager MA,Rybicki FJ,Mulkern RV

更新日期：2009-09-01 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：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：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：:Spatial resolution in 3D breath-hold coronary MR angiography (MRA) is limited by imaging time. The purpose of this work was to investigate the feasibility of improving the spatial resolution of coronary MRA using generalized autocalibrating partially parallel acquisition (GRAPPA) and fast imaging with steady state pre...

journal_title：Magnetic resonance in medicine

authors： Park J,McCarthy R,Li D

更新日期：2004-07-01 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

abstract：PURPOSE:Investigation of the feasibility to perform high-resolution quantitative sodium imaging at 9.4 Tesla (T). METHODS:A proton patch antenna was combined with a sodium birdcage coil to provide a proton signal without compromising the efficiency of the X-nucleus coil. Sodium density weighted images with a nominal r...

journal_title：Magnetic resonance in medicine

authors： Mirkes CC,Hoffmann J,Shajan G,Pohmann R,Scheffler K

更新日期：2015-01-01 00:00:00

abstract：:Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevert...

journal_title：Magnetic resonance in medicine

authors： Lin FH,Wang FN,Ahlfors SP,Hämäläinen MS,Belliveau JW

更新日期：2007-10-01 00:00:00

abstract：:Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference betwee...

journal_title：Magnetic resonance in medicine

authors： Childs C,Hiltunen Y,Vidyasagar R,Kauppinen RA

更新日期：2007-01-01 00:00:00

abstract：:When using tracer kinetic modeling to analyze dynamic contrast-enhanced MRI (DCE-MRI) it is necessary to identify an appropriate arterial input function (AIF). The measured AIF is often poorly sampled in both clinical and preclinical MR systems due to the initial rapid increase in contrast agent concentration and the ...

journal_title：Magnetic resonance in medicine

authors： McGrath DM,Bradley DP,Tessier JL,Lacey T,Taylor CJ,Parker GJ

更新日期：2009-05-01 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：:We present a new steady-state imaging sequence, which simultaneously allows in a single acquisition the formation of two MR images with clearly different contrasts. The contrast of the first image is FISP-like, whereas the second image is strongly T2-weighted. In principle the T2 values in the image can be calculated ...

journal_title：Magnetic resonance in medicine

authors： Bruder H,Fischer H,Graumann R,Deimling M

更新日期：1988-05-01 00:00:00

abstract：:Quantitative 1H MRS to determine cerebral metabolite patterns and MRI to determine CSF flow were applied to 12 patients with ventricular dilation-Group A, cortical atrophy (N = 5); or Group B, hydrocephalus (N = 7)- and in 9 normal controls. While mean brain water (Group A = 80% +/- 6; Group B = 86% +/- 5; normal = 85...

journal_title：Magnetic resonance in medicine

authors： Bluml S,McComb JG,Ross BD

更新日期：1997-03-01 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：:It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...

journal_title：Magnetic resonance in medicine

authors： Williamson DS,Mulken RV,Jakab PD,Jolesz FA

更新日期：1996-04-01 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：:The complexity of biologic tissues, with multiple compartments each with its own diffusion and relaxation properties, requires complex formalisms to model water signal in most magnetic resonance imaging or magnetic resonance spectroscopy experiments. In this article, we describe a magnetic susceptibility-induced shift...

journal_title：Magnetic resonance in medicine

authors： Galons JP,Lope-Piedrafita S,Divijak JL,Corum C,Gillies RJ,Trouard TP

更新日期：2005-07-01 00:00:00

abstract：:Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra-high-field MR. Transmit coil arrays enable such techniques as B(1) (+) shimming to substantially improve transmit B(1) homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imagin...

journal_title：Magnetic resonance in medicine

authors： Adriany G,Auerbach EJ,Snyder CJ,Gözübüyük A,Moeller S,Ritter J,Van de Moortele PF,Vaughan T,Uğurbil K

更新日期：2010-06-01 00:00:00

abstract：PURPOSE:The ultimate intrinsic signal-to-noise ratio (UISNR) is normally calculated using electrodynamic simulations with a complete basis of modes. Here, we provide an exact solution for the UISNR at the center of a dielectric sphere and assess how accurately this solution approximates UISNR away from the center. MET...

journal_title：Magnetic resonance in medicine

authors： Lee HH,Sodickson DK,Lattanzi R

更新日期：2018-11-01 00:00:00

abstract：:The orientation dependence of the free induction decay (FID) of 1H NMR water signal in ex vivo bovine digital flexor tendon at the native level of hydration is reported. Residual dipolar coupling due to the overall tissue anisotropy produces a 6:1 change in the signal intensity as an angle between the long axis of a s...

journal_title：Magnetic resonance in medicine

authors： Krasnosselskaia LV,Fullerton GD,Dodd SJ,Cameron IL

更新日期：2005-08-01 00:00:00

abstract：:Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high-field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in...

journal_title：Magnetic resonance in medicine

authors： Mao W,Smith MB,Collins CM

更新日期：2006-10-01 00:00:00

abstract：:A novel center-out 3D trajectory for sampling magnetic resonance data is presented. The trajectory set is based on a single Fermat spiral waveform, which is substantially undersampled in the center of k-space. Multiple trajectories are combined in a "stacked cone" configuration to give very uniform sampling throughout...

journal_title：Magnetic resonance in medicine

authors： Pipe JG,Zwart NR,Aboussouan EA,Robison RK,Devaraj A,Johnson KO

更新日期：2011-11-01 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：:Parallel excitation is being studied intensively for applications in MR imaging and in particular for selecting arbitrary shapes as regions of interest. In this work, parallel excitation was applied to arbitrarily shaped voxel selection in spectroscopy and investigated for different excitation k-space trajectories (ra...

journal_title：Magnetic resonance in medicine

authors： Snyder J,Haas M,Hennig J,Zaitsev M

更新日期：2012-02-01 00:00:00

abstract：:Sensitivity encoding is used to improve the performance of real-time MRI. The encoding efficiency of single-shot and segmented echo-planar imaging is tripled by means of a 6-element receiver coil array. The feasibility of this approach is verified for double oblique cardiac real-time imaging of human subjects at rest ...

journal_title：Magnetic resonance in medicine

authors： Weiger M,Pruessmann KP,Boesiger P

更新日期：2000-02-01 00:00:00

abstract：:Orientational anisotropy of T2 and T1 relaxation times, diffusion, and magnetization transfer has been investigated for six different tissues: tendon, cartilage, kidney, muscle, white matter, and optic nerve. Relaxation anisotropy was observed for tendon and cartilage, and diffusional anisotropy was measured in kidney...

journal_title：Magnetic resonance in medicine

authors： Henkelman RM,Stanisz GJ,Kim JK,Bronskill MJ

更新日期：1994-11-01 00:00:00

abstract：:The fast spin-echo (FSE) sequence is frequently used as a fast data-readout technique in conjunction with other pulse sequence elements, such as in fluid-attenuated inversion-recovery (FLAIR) and double inversion-recovery (DIR) sequences. In order to implement those pulse sequences, an understanding is required of how...

journal_title：Magnetic resonance in medicine

authors： Meara SJ,Barker GJ

更新日期：2005-07-01 00:00:00

abstract：:Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid ...

journal_title：Magnetic resonance in medicine

authors： Poulin E,Lebel R,Croteau E,Blanchette M,Tremblay L,Lecomte R,Bentourkia M,Lepage M

更新日期：2013-03-01 00:00:00

abstract：:A simple (2)H NMR method for quantifying absolute (2)H-enrichments in all seven aliphatic positions of glucose following its derivatization to monoacetone glucose is presented. The method is based on the addition of a small quantity of (2)H-enriched formate to the NMR sample. When the method was applied to [2-(2)H]mon...

journal_title：Magnetic resonance in medicine

authors： Jones JG,Perdigoto R,Rodrigues TB,Geraldes CF

更新日期：2002-09-01 00:00:00

abstract：PURPOSE:To verify MR measurements of myocardial extracellular volume fraction (ECV) based on clinically applicable T1-mapping sequences against ECV measurements by radioisotope tracer in pigs and to relate the results to those obtained in volunteers. METHODS:Between May 2016 and March 2017, 8 volunteers (25 ± 4 years,...

journal_title：Magnetic resonance in medicine

authors： Nordlund D,Xanthis C,Bidhult S,Jablonowski R,Kanski M,Kopic S,Carlsson M,Engblom H,Aletras AH,Arheden H

更新日期：2020-02-01 00:00:00