Improved myocardial tagging contrast.

abstract：PURPOSE:To investigate the feasibility of estimating calibration constants (K and T2o ) in vivo for converting whole-blood T2 to blood hemoglobin oxygen saturation (HbO2 ) according to the Luz-Meiboom model, 1/T2=1/T2o+K(1-HbO2)2, where K and T2o are relaxivity and transverse relaxation time of fully saturated blood, r...

journal_title：Magnetic resonance in medicine

authors： Langham MC,Rodríguez-Soto AE,Schwartz N,Wehrli FW

更新日期：2018-04-01 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：PURPOSE:MR fingerprinting (MRF) is a technique for quantitative tissue mapping using pseudorandom measurements. To estimate tissue properties such as T1 , T2 , proton density, and B0 , the rapidly acquired data are compared against a large dictionary of Bloch simulations. This matching process can be a very computation...

journal_title：Magnetic resonance in medicine

authors： Cauley SF,Setsompop K,Ma D,Jiang Y,Ye H,Adalsteinsson E,Griswold MA,Wald LL

更新日期：2015-08-01 00:00:00

abstract：PURPOSE:To develop an analytically based algorithm for rapid optimization of the local radiofrequency magnetic (B1+) field intensity for a given radiofrequency power through a transmit array. The analytical nature of the method will yield insight to optimization requirements and provides a valuable reference for numeri...

journal_title：Magnetic resonance in medicine

authors： Carluccio G,Collins CM,Erricolo D

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:Over the last two decades, extended criteria have promoted an increased number of donor livers available for liver transplantation. But posttransplant graft loss is still a major concern. Macrovesicular hepatic steatosis (MHS) is recognized as the most significant prognostic histologic parameter in predicting p...

journal_title：Magnetic resonance in medicine

authors： Chen G,Jiang J,Wang X,Yang M,Xie Y,Guo H,Tang H,Zhou L,Hu D,Kamel IR,Chen Z,Li Z

更新日期：2020-11-16 00:00:00

abstract：PURPOSE:To develop a prospective baseline enhancement that compensates for intermingled background effects in Z-spectra to achieve sensitivity enhancement of peaks related to CEST and nuclear Overhauser effect. METHODS:An MRI sequence-specific compensation of background effects is achieved through variation of the pul...

journal_title：Magnetic resonance in medicine

authors： Lenich T,Pampel A,Mildner T,Möller HE

更新日期：2019-04-01 00:00:00

abstract：:Saline solutions of manganese ions (Mn2+) were used as articular contrast agents in magnetic resonance microscopy (9.4 T) of cartilage of chicken femoral condyles and pig temporomandibular joints. The diffusion of Mn2+ from the articular surface into the cartilage matrix led to a strong contrast enhancement in the car...

journal_title：Magnetic resonance in medicine

authors： Kusaka Y,Gründer W,Rumpel H,Dannhauer KH,Gersonde K

更新日期：1992-03-01 00:00:00

abstract：PURPOSE:For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, w...

journal_title：Magnetic resonance in medicine

authors： Ahmad R,Xue H,Giri S,Ding Y,Craft J,Simonetti OP

更新日期：2015-11-01 00:00:00

abstract：:In in vivo (1)H spectroscopy, the signal at 1.32 ppm is usually assigned to lactate. This resonance position is shared with threonine at physiological pH. The similarity of spectral patterns of lactate and threonine renders the separate measurement of either threonine or lactate without and even with editing technical...

journal_title：Magnetic resonance in medicine

authors： Marjanska M,Henry PG,Uğurbil K,Gruetter R

更新日期：2008-02-01 00:00:00

abstract：PURPOSE:To examine the detection sensitivity for the rapidly exchanging hydroxyl protons of D-glucose using the recently developed on-resonance variable delay multi-pulse (onVDMP) chemical exchange saturation transfer (CEST) technique. METHODS:The onVDMP method was applied for the detection of water signal changes upo...

journal_title：Magnetic resonance in medicine

authors： Xu X,Xu J,Chan KWY,Liu J,Liu H,Li Y,Chen L,Liu G,van Zijl PCM

更新日期：2019-01-01 00:00:00

abstract：:We applied diffusion-sensitive echo planar (Instascan) imaging to study thermal changes caused by a Nd:YAG laser. Images of phantom materials and normal rabbit brain tissue in vivo, acquired in 150 ms, every 2s, clearly showed the dynamics of temperature-related signal intensity changes in the regions irradiated by th...

journal_title：Magnetic resonance in medicine

authors： Bleier AR,Jolesz FA,Cohen MS,Weisskoff RM,Dalcanton JJ,Higuchi N,Feinberg DA,Rosen BR,McKinstry RC,Hushek SG

更新日期：1991-09-01 00:00:00

abstract：:Balanced steady-state free precession (SSFP) imaging is sensitive to off-resonance effects, which can lead to considerable artifacts during a transient phase following magnetization preparation or steady-state interruption. In addition, nonlinear k-space encoding is required if contrast-relevant k-space regions need t...

journal_title：Magnetic resonance in medicine

authors： Markl M,Leupold J,Bieri O,Scheffler K,Hennig J

更新日期：2005-10-01 00:00:00

abstract：:The recently developed technique of gradient, high-resolution magic-angle spinning NMR (g-hr-MAS-NMR) spectroscopy was applied to the study of ex vivo human lipoma and liposarcoma tissue. Compared with conventional 1H-NMR, the g-hr-MAS method yielded a large improvement in spectral resolution and permitted the detecti...

journal_title：Magnetic resonance in medicine

authors： Millis KK,Maas WE,Cory DG,Singer S

更新日期：1997-09-01 00:00:00

abstract：:To increase image acquisition efficiency, we develop alternative gradient encoding strategies designed to provide spatial encoding complementary to the spatial encoding provided by the multiple receiver coil elements in parallel image acquisitions. Intuitively, complementary encoding is achieved when the magnetic fiel...

journal_title：Magnetic resonance in medicine

authors： Tam LK,Stockmann JP,Galiana G,Constable RT

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:We investigated global specific absorption rate (SAR) and radiofrequency (RF) power requirements in parallel transmission as the distance between the transmit coils and the sample was increased. METHODS:We calculated ultimate intrinsic SAR (UISAR), which depends on object geometry and electrical properties but...

journal_title：Magnetic resonance in medicine

authors： Deniz CM,Vaidya MV,Sodickson DK,Lattanzi R

更新日期：2016-01-01 00:00:00

abstract：:Intra-plaque hemorrhage (IPH) and lipid core, characteristics of rupture prone carotid plaques, are often visualized in vivo with MRI using T1 weighted gradient and spin echo, respectively. Increasing magnetic field strength may help to identify IPH and lipid core better. As a proof of concept, automatic segmentation ...

journal_title：Magnetic resonance in medicine

authors： te Boekhorst BC,van 't Klooster R,Bovens SM,van de Kolk KW,Cramer MJ,van Oosterhout MF,Doevendans PA,van der Geest RJ,Pasterkamp G,van Echteld CJ

更新日期：2012-06-01 00:00:00

abstract：PURPOSE:Cardiac T1 mapping has become an increasingly important imaging technique, contributing novel diagnostic options. However, currently utilized methods are often associated with accuracy problems because of heart rate variations and cardiac arrhythmia, limiting their value in clinical routine. This study aimed to...

journal_title：Magnetic resonance in medicine

authors： Gensler D,Salinger T,Düring M,Lorenz K,Jahns R,Wech T,Frantz S,Ertl G,Jakob PM,Nordbeck P

更新日期：2019-03-01 00:00:00

abstract：PURPOSE:To measure the apparent diffusion coefficients (ADC) of five main metabolites in the human brain at 3T with PRESS and STEAM, avoiding measurement biases because of cross-terms. Cross-terms arise from interactions between slice-selection and spoiler gradients in the localized spectroscopy sequence and the diffus...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Auerbach EJ,Marjańska M

更新日期：2018-06-01 00:00:00

abstract：PURPOSE:Coil-by-coil reconstruction methods are followed by coil combination to obtain a single image representing a spin density map. Typical coil combination methods, such as square-root sum-of-squares and adaptive coil combining, yield images that exhibit spatially varying modulation of image intensity. Existing pra...

journal_title：Magnetic resonance in medicine

authors： Gol Gungor D,Potter LC

更新日期：2016-02-01 00:00:00

abstract：:Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arteri...

journal_title：Magnetic resonance in medicine

authors： Newbould RD,Skare ST,Jochimsen TH,Alley MT,Moseley ME,Albers GW,Bammer R

更新日期：2007-07-01 00:00:00

abstract：:Image reconstruction of tagged cardiac MR images using complementary spatial modulation of magnetization (CSPAMM) requires the subtraction of two complex datasets to remove the untagged signal. Although the resultant images typically have sharper and more persistent tags than images formed without complementary taggin...

journal_title：Magnetic resonance in medicine

authors： NessAiver M,Prince JL

更新日期：2003-08-01 00:00:00

abstract：PURPOSE:A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements. THEORY AND METHODS:An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into ...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Yan X,Gore JC,Grissom WA

更新日期：2020-06-01 00:00:00

abstract：:Optimal control theory has been applied in the past for the design of RF pulses for selective excitation. This was the outcome of having established the controllability of the MR spin system for the selective excitation problem. "Minimum distance" was the main formulation used for the solution. Because of their robust...

journal_title：Magnetic resonance in medicine

authors： Rosenfeld D,Zur Y

更新日期：1996-09-01 00:00:00

abstract：PURPOSE:Preclinical imaging of myocardial blood flow (MBF) can elucidate molecular mechanisms underlying cardiovascular disease. We compared the repeatability and variability of two methods, first-pass MRI and arterial spin labeling (ASL), for imaging MBF in mice. METHODS:Quantitative perfusion MRI in mice was perform...

journal_title：Magnetic resonance in medicine

authors： Naresh NK,Chen X,Moran E,Tian Y,French BA,Epstein FH

更新日期：2016-06-01 00:00:00

abstract：:Half k-space gradient-recalled echo-planar imaging (GR-EPI) is discussed in detail. T2* decay during full k-space GR-EPI gives rise to unequal weighting of the lines of k-space, loss of signal intensity at the center of k-space, and a point-spread function that limits resolution. In addition, the long readout time for...

journal_title：Magnetic resonance in medicine

authors： Jesmanowicz A,Bandettini PA,Hyde JS

更新日期：1998-11-01 00:00:00

abstract：:A novel and automated technique is described for removing fMRI image artifacts resulting from motion outside of the imaging field of view. The technique is based on the Stockwell transform (ST), a mathematical operation that provides the frequency content at each time point within a time-varying signal. Using this tec...

journal_title：Magnetic resonance in medicine

authors： Goodyear BG,Zhu H,Brown RA,Mitchell JR

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:Define criteria for selection of optimal flip angle sets for T1 estimation and evaluate effects on T1 mapping. THEORY AND METHODS:Flip angle sets for spoiled gradient echo-based T1 mapping were selected by minimizing T1 estimate variance weighted by the joint density of M0 and T1 in an initial acquisition. The...

journal_title：Magnetic resonance in medicine

authors： Lewis CM,Hurley SA,Meyerand ME,Koay CG

更新日期：2016-09-01 00:00:00

abstract：:The combination of a frequency nonselective excitation suppression method (1331 sequence) with selective excitation followed by gradient-induced dephasing of water transverse magnetization yielded suppression ratios of greater than 10,000:1. The need for gradient preemphasis and correction of B0 field shifts is discus...

journal_title：Magnetic resonance in medicine

authors： Brereton IM,Field J,Moxon LN,Irving MG,Doddrell DM

更新日期：1989-01-01 00:00:00

abstract：:Certain kinds of artifacts have been reported when projection reconstruction (PR) techniques are used in magnetic resonance imaging (MRI). These will occur if the spacing between samples in k-space is too large. It has been suggested that PR requires finer k-space sampling than does two-dimensional Fourier reconstruct...

journal_title：Magnetic resonance in medicine

authors： Joseph PM

更新日期：1998-09-01 00:00:00

abstract：PURPOSE:To obtain whole-brain high-resolution T2 maps in 2 minutes by combining simultaneous multislice excitation and low-power PINS (power independent of number of slices) refocusing pulses with undersampling and a model-based reconstruction. METHODS:A multi-echo spin-echo sequence was modified to acquire multiple s...

journal_title：Magnetic resonance in medicine

authors： Hilbert T,Schulz J,Marques JP,Thiran JP,Krueger G,Norris DG,Kober T

更新日期：2019-12-01 00:00:00