Assessment and compensation of susceptibility artifacts in gradient echo MRI of hyperpolarized 3He gas.

abstract：PURPOSE:To investigate whether saturation using existing methods developed for 3T imaging is feasible for clinical perfusion imaging at 7T, and to propose a new design of saturation pulse train for first-pass myocardial perfusion imaging at 7T. METHODS:The new design of saturation pulse train consists of four hyperbol...

journal_title：Magnetic resonance in medicine

authors： Tao Y,Hess AT,Keith GA,Rodgers CT,Liu A,Francis JM,Neubauer S,Robson MD

更新日期：2015-04-01 00:00:00

abstract：:MRI using hyperpolarized (13) C-labeled pyruvate is a promising tool to biochemically profile tumors and monitor their response to therapy. This technique requires injection of pyruvate into tumor-bearing animals. Pyruvate is an endogenous entity but the influence of exogenously injected bolus doses of pyruvate on tum...

journal_title：Magnetic resonance in medicine

authors： Saito K,Matsumoto S,Devasahayam N,Subramanian S,Munasinghe JP,Morris HD,Lizak MJ,Ardenkjaer-Larsen JH,Mitchell JB,Krishna MC

更新日期：2012-03-01 00:00:00

abstract：:This paper describes a technique for characterizing the gradient subsystem of a magnetic resonance (MR) system. The technique uses a Fourier-transform analysis to directly measure the k-space trajectory produced by an arbitrary gradient waveform. In addition, the method can be easily extended to multiple dimensions an...

journal_title：Magnetic resonance in medicine

authors： Alley MT,Glover GH,Pelc NJ

更新日期：1998-04-01 00:00:00

abstract：:This study presents the detection of [2-(13)C]glucose metabolism in the carboxylic/amide region in the human brain, and demonstrates that the cerebral metabolism of [2-(13)C]glucose can be studied in human subjects in the presence of severe hardware constraints of widely available 3 T clinical scanners and with low-po...

journal_title：Magnetic resonance in medicine

authors： Li S,Zhang Y,Wang S,Yang J,Ferraris Araneta M,Farris A,Johnson C,Fox S,Innis R,Shen J

更新日期：2009-09-01 00:00:00

abstract：:The design of a piezoelectric-controlled trimmer capacitor and its use as a tuning element of an MRI surface coil at 63.8 MHz are described. It is found that image quality does not depend strongly on match of the coil to the transmission line but that tuning can be a significant factor. The work is intended to lead ev...

journal_title：Magnetic resonance in medicine

authors： Hyde JS,Rilling RJ,Jesmanowicz A,Kneeland JB

更新日期：1989-10-01 00:00:00

abstract：:Dynamic susceptibility contrast (DSC) MRI is now increasingly used for measuring perfusion in many different applications. The quantification of DSC data requires the measurement of the arterial input function (AIF) and the deconvolution of the tissue concentration time curve. One of the most accepted deconvolution me...

journal_title：Magnetic resonance in medicine

authors： Calamante F,Gadian DG,Connelly A

更新日期：2000-09-01 00:00:00

abstract：PURPOSE:To test octafluorocyclobutane (OFCB) as an inhalation contrast agent for fluorine-19 MRI of the lung, and to compare the image quality of OFCB scans with perfluoropropane (PFP) scans THEORY AND METHODS: After normalizing for the number of signal averages, a theoretical comparison between the OFCB signal-to-nois...

journal_title：Magnetic resonance in medicine

authors： Shepelytskyi Y,Li T,Grynko V,Newman C,Hane FT,Albert MS

更新日期：2021-02-01 00:00:00

abstract：:An eight-channel receive-only brain coil and table-top detunable volume transmit coil were developed and tested at 7 T for human imaging. Optimization of this device required attention to sources of interaction between the array elements, between the transmit and receive coils and minimization of common mode currents ...

journal_title：Magnetic resonance in medicine

authors： Wiggins GC,Potthast A,Triantafyllou C,Wiggins CJ,Wald LL

更新日期：2005-07-01 00:00:00

abstract：PURPOSE:A target-pattern-driven (TD) trajectory design is introduced in combination with parallel transmit (pTX) radiofrequency (RF) pulses to provide localized suppression of unwanted signals. The design incorporates target-pattern and B1+ information to adjust denser sampling and coverage in k-space regions where the...

journal_title：Magnetic resonance in medicine

authors： Schneider R,Haueisen J,Pfeuffer J

更新日期：2014-10-01 00:00:00

abstract：PURPOSE:To demonstrate dynamic slice-dependent shim update as a simple method to reduce susceptibility-induced B0 inhomogeneity and associated pixel shift artifacts in diffusion-weighted echo planar imaging (DW-EPI) in 3 T breast imaging. METHODS:Dynamic slice-dependent update of linear shim and center frequency was i...

journal_title：Magnetic resonance in medicine

authors： Lee SK,Tan ET,Govenkar A,Hancu I

更新日期：2014-05-01 00:00:00

abstract：:Patient motion and image distortion induced by eddy currents cause artifacts in maps of diffusion parameters computed from diffusion-weighted (DW) images. A novel and comprehensive approach to correct for spatial misalignment of DW imaging (DWI) volumes acquired with different strengths and orientations of the diffusi...

journal_title：Magnetic resonance in medicine

authors： Rohde GK,Barnett AS,Basser PJ,Marenco S,Pierpaoli C

更新日期：2004-01-01 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：:Brain water diffusion in response to transient global ischemia (12 min), reperfusion (60 min), and cardiac arrest was monitored by localized proton magnetic resonance spectroscopy. The trace of the apparent diffusion coefficient tensor (ADC(Av)) was determined at high temporal resolution (10 sec) to assess the putativ...

journal_title：Magnetic resonance in medicine

authors： Wick M,Fujimori H,Michaelis T,Frahm J

更新日期：1999-10-01 00:00:00

abstract：:Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice prof...

journal_title：Magnetic resonance in medicine

authors： Keilholz-George SD,Knight-Scott J,Berr SS

更新日期：2001-07-01 00:00:00

abstract：PURPOSE:Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay with time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but the method is sensitive to other sources of spatio-temporal signal change such as diffusion. The purpose of this work was to assess th...

journal_title：Magnetic resonance in medicine

authors： Marshall H,Parra-Robles J,Deppe MH,Lipson DA,Lawson R,Wild JM

更新日期：2014-03-01 00:00:00

abstract：:Regional values of fractional anisotropy (FA) and mean diffusivity (D(av)) of in vivo and excised rat spinal cords were measured using an iscosahedral encoding scheme that is based on 21 uniformly distributed and alternating gradient directions with an echo planar imaging (EPI) readout. Based on the water phantom stud...

journal_title：Magnetic resonance in medicine

authors： Madi S,Hasan KM,Narayana PA

更新日期：2005-01-01 00:00:00

abstract：:MR techniques have proven their ability to investigate skeletal muscle function in situ. Their benefit in terms of noninvasiveness is, however, lost in animal research, given that muscle stimulation and force output measurements are usually achieved using invasive surgical procedures, thereby excluding repeated invest...

journal_title：Magnetic resonance in medicine

authors： Giannesini B,Vilmen C,Le Fur Y,Dalmasso C,Cozzone PJ,Bendahan D

更新日期：2010-07-01 00:00:00

abstract：:A method is presented that improves the effectiveness of RF-spoiling whenever an image consists of the averaging of several identical single acquisitions. Using this method, it becomes possible to reduce the necessary moment of the spoiler gradient by a factor equal to the number of averages. The idea is to perform th...

journal_title：Magnetic resonance in medicine

authors： Leupold J,Hennig J

更新日期：2011-10-01 00:00:00

abstract：:Consideration of spatially variable noise fields is becoming increasingly necessary in MRI given recent innovations in artifact identification and statistically driven image processing. Fast imaging methods enable study of difficult anatomical targets and improve image quality but also increase the spatial variability...

journal_title：Magnetic resonance in medicine

authors： Landman BA,Bazin PL,Smith SA,Prince JL

更新日期：2009-08-01 00:00:00

abstract：:Mathematical models are required to estimate kinetic parameters of [1-(13)C] pyruvate-lactate interconversion from magnetic resonance spectroscopy data. One- or two-way exchange models utilizing a hypothetical approximation to the true arterial input function (AIF), (e.g. an ideal 'box-car' function) have been used pr...

journal_title：Magnetic resonance in medicine

authors： Kazan SM,Reynolds S,Kennerley A,Wholey E,Bluff JE,Berwick J,Cunningham VJ,Paley MN,Tozer GM

更新日期：2013-10-01 00:00:00

abstract：:A comparison between contrast and signal-to-noise ratio (SNR), as obtained by both maximum entropy (ME) and 2DFT reconstruction, is reported for NMR images. Our results show that in the ME elaboration the contrast and SNR are generally increased with respect to the 2DFT elaboration. The magnitude of such an increase d...

journal_title：Magnetic resonance in medicine

authors： De Simone BC,De Luca F,Maraviglia B

更新日期：1988-11-01 00:00:00

abstract：PURPOSE:The purpose of this work was to develop a rapid and robust whole-body fat-water MRI (FWMRI) method using a continuously moving table (CMT) with dynamic field corrections at 3 Tesla. METHODS:CMT FWMRI was developed at 3 Tesla with a multiecho golden angle (GA) radial trajectory and dynamic B0 field shimming. Wh...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Smith DS,Gifford A,Welch EB

更新日期：2016-07-01 00:00:00

abstract：:Metallic particles have shaped the use of magnetic resonance imaging (MRI) for molecular and cellular imaging. Although these particles have generally been developed for extracellular residence, either as blood pool contrast agents or targeted contrast agents, the coopted use of these particles for intracellular label...

journal_title：Magnetic resonance in medicine

authors： Shapiro EM

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:Magnetic resonance (MR) cholangiopancreatography (MRCP) is an established specialist method for imaging the upper abdomen and biliary/pancreatic ducts. Due to limitations of either MR image contrast or low through-plane resolution, patients may require further evaluation with contrast-enhanced computed tomograp...

journal_title：Magnetic resonance in medicine

authors： Ebner M,Patel PA,Atkinson D,Caselton L,Firmin L,Amin Z,Bainbridge A,De Coppi P,Taylor SA,Ourselin S,Chouhan MD,Vercauteren T

更新日期：2019-11-01 00:00:00

abstract：:Amide proton transfer imaging, a specific form of chemical exchange saturation transfer imaging, has previously been applied to studies of acute ischemic acidosis, stroke, and cancer. However, interpreting the resulting contrast is complicated by its dependence on the exchange rate between amides and water, the amide ...

journal_title：Magnetic resonance in medicine

authors： Zu Z,Janve VA,Li K,Does MD,Gore JC,Gochberg DF

更新日期：2012-09-01 00:00:00

abstract：PURPOSE:Balanced steady state free precession (bSSFP) imaging suffers from off-resonance artifacts such as signal modulation and banding. Solutions for removal of bSSFP off-resonance dependence are described and compared, and an optimal solution is proposed. THEORY AND METHODS:An Algebraic Solution (AS) that complemen...

journal_title：Magnetic resonance in medicine

authors： Hoff MN,Andre JB,Xiang QS

更新日期：2017-02-01 00:00:00

abstract：:The reconstruction of non-Cartesian k-space trajectories often requires the estimation of nonuniform sampling density. Particularly for 3D, this calculation can be computationally expensive. The method proposed in this work combines an iterative algorithm previously proposed by Pipe and Menon (Magn Reson Med 1999;41:1...

journal_title：Magnetic resonance in medicine

authors： Zwart NR,Johnson KO,Pipe JG

更新日期：2012-03-01 00:00:00

abstract：:Manganese-enhanced MRI has previously been used for visualization of brain architecture and functional mapping of neural pathways. The present work investigated the potential of manganese-enhanced MRI for noninvasive imaging of salivary glands in living subjects. Marked shortening of T(1) was observed in salivary glan...

journal_title：Magnetic resonance in medicine

authors： Seshadri M,Hoy A

更新日期：2010-09-01 00:00:00

abstract：:The feasibility of reconstructing three-dimensional (3D) MRI data sets from limited-view projections is investigated in phantom and in vivo animal studies to improve the temporal resolution of magnetic resonance angiography without sacrificing spatial resolution. Thirty-two pairs of orthogonal biplane projections are ...

journal_title：Magnetic resonance in medicine

authors： Huang Y,Gurr D,Wright GA

更新日期：2006-01-01 00:00:00

abstract：:The advantages of electron paramagnetic resonance (EPR) imaging at L-band frequencies are discussed. The construction and calibration of a low-field L-band EPR imaging spectrometer is described with capillary phantoms containing aqueous nitroxides as paramagnetic imaging agents. The peak separation induced by the magn...

journal_title：Magnetic resonance in medicine

authors： Fujii H,Berliner LJ

更新日期：1985-06-01 00:00:00