Quantitative measurement of regional lung ventilation using 3He MRI.

abstract：PURPOSE:The oxygen extraction fraction (OEF) is an important biomarker for tissue-viability. MRI enables noninvasive estimation of the OEF based on the blood-oxygenation-level-dependent (BOLD) effect. Quantitative OEF-mapping is commonly applied using least-squares regression (LSR) to an analytical tissue model. Howeve...

journal_title：Magnetic resonance in medicine

authors： Domsch S,Mürle B,Weingärtner S,Zapp J,Wenz F,Schad LR

更新日期：2018-02-01 00:00:00

abstract：:The magnetization subtraction technique (MS), which is equivalent to the inversion recovery technique in strong magnetic fields, has been implemented in dynamic nuclear polarization-enhanced magnetic resonance imaging (DNPI). The general theoretical basis of the MS method, which can be applied to DNPI or to prepolariz...

journal_title：Magnetic resonance in medicine

authors： Planinsic G,Grucker D,Stepisnik J

更新日期：1996-03-01 00:00:00

abstract：:Variable nutation SSFP (DESPOT2) permits rapid, high-resolution determination of the transverse (T2) relaxation constant. A limitation of DESPOT2, however, is the presence of T2 voids due to off-resonance banding artifacts associated with SSFP images. These artifacts typically occur in images acquired with long repeti...

journal_title：Magnetic resonance in medicine

authors： Deoni SC,Ward HA,Peters TM,Rutt BK

更新日期：2004-08-01 00:00:00

abstract：PURPOSE:To test the efficacy of 7T MRS for in vivo detection of 2-hydroxyglutarate (2HG) in brain tumors. METHODS:The subecho times of point-resolved spectroscopy (PRESS) were optimized at 7T with density-matrix simulations and phantom validation to improve the 2HG signal selectivity with respect to the neighboring re...

journal_title：Magnetic resonance in medicine

authors： Ganji SK,An Z,Tiwari V,McNeil S,Pinho MC,Pan E,Mickey BE,Maher EA,Choi C

更新日期：2017-03-01 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：:A modified high-speed stimulated-echo acquisition mode (STEAM) diffusion sequence (90 degrees-TE/2-90 degrees-TM-[alpha-TE/2-STE]n) incorporating bipolar diffusion gradients that are less sensitive to macroscopic motion-induced artifacts is presented. Diffusion encoding was performed only during the first echo interva...

journal_title：Magnetic resonance in medicine

authors： Yongbi MN,Ding S,Dunn JF

更新日期：1996-06-01 00:00:00

abstract：:An automatic fMRI protocol for the investigation of the human auditory cortex has been developed. For the activation of the auditory system, the scanner noise itself is the source of sound. Rapid switching of B0 gradients allows the generation of tones of defined frequencies and amplitude on a conventional scanner wit...

journal_title：Magnetic resonance in medicine

authors： Bilecen D,Radü EW,Scheffler K

更新日期：1998-12-01 00:00:00

abstract：PURPOSE:Direct mapping of neuronal currents using MRI would have fundamental impacts on brain functional imaging. Previous reports indicated that the stimulus-induced rotary saturation (SIRS) mechanism had the best potential of direct detection of neural oscillations; however, it lacked the high-sensitivity level neede...

journal_title：Magnetic resonance in medicine

authors： Jiang X,Sheng J,Li H,Chai Y,Zhou X,Wu B,Guo X,Gao JH

更新日期：2016-02-01 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：:Functional MRI (fMRI) was used to assess proprioceptive-associated cervical cord activity in 24 relapsing multiple sclerosis (MS) patients and 10 controls. Cord and brain conventional and diffusion tensor (DT) MRI were also acquired. fMRI was performed using a block design during a proprioceptive stimulation consistin...

journal_title：Magnetic resonance in medicine

authors： Agosta F,Valsasina P,Rocca MA,Caputo D,Sala S,Judica E,Stroman PW,Filippi M

更新日期：2008-05-01 00:00:00

abstract：:Quantitative estimation of T1 is a challenging but important task inherent to many clinical applications. The most commonly used paradigm for estimating T1 in vivo involves performing a sequence of spoiled gradient-recalled echo acquisitions at different flip angles, followed by fitting of an exponential model to the ...

journal_title：Magnetic resonance in medicine

authors： Trzasko JD,Mostardi PM,Riederer SJ,Manduca A

更新日期：2013-06-01 00:00:00

abstract：PURPOSE:To develop a wideband cardiac perfusion pulse sequence and test whether it is capable of suppressing image artifacts in patients with a cardiac implantable electronic device (CIED), while not exceeding the specific absorption rate (SAR) limit (2.0 W/kg). METHODS:A wideband perfusion pulse sequence was develope...

journal_title：Magnetic resonance in medicine

authors： Hong K,Collins JD,Knight BP,Carr JC,Lee DC,Kim D

更新日期：2019-02-01 00:00:00

abstract：PURPOSE:This study aimed to evaluate the reproducibility and specificity of quantitative magnetization transfer (qMT) imaging for monitoring spinal cord injuries (SCIs). METHODS:MRI scans were performed in anesthetized monkeys at 9.4T, before and serially after a unilateral lesion of the cervical spinal cord. A two-po...

journal_title：Magnetic resonance in medicine

authors： Wang F,Li K,Mishra A,Gochberg D,Min Chen L,Gore JC

更新日期：2016-04-01 00:00:00

abstract：:Simulations of dynamic susceptibility contrast (DSC) MRI are frequently performed by assuming a certain shape for the input function and the microvascular response function. However, to investigate the influence of parameters that will affect the shape of the input function, a more complex model of the human vasculatu...

journal_title：Magnetic resonance in medicine

authors： van Osch MJ,Vonken EJ,Wu O,Viergever MA,van der Grond J,Bakker CJ

更新日期：2003-09-01 00:00:00

abstract：:A simple theoretical model was developed to compare the sensitivities (i.e., signal-to-noise ratios per unit imaging time) of two-dimensional (2D) multislice and 3D imaging sequences. The model shows that the sensitivities of 3D and 2D multislice MRI sequences are usually similar. Sensitivities are identical in T2-wei...

journal_title：Magnetic resonance in medicine

authors： Johnson G,Wadghiri YZ,Turnbull DH

更新日期：1999-04-01 00:00:00

abstract：PURPOSE:Continuously moving table (CMT) MRI is a high throughput technique that has multiple applications in whole-body imaging. In this work, CMT MRI based on golden angle (GA, 111.246° azimuthal step) radial sampling is developed at 3 Tesla (T), with the goal of increased flexibility in image reconstruction using arb...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Smith DS,Welch EB

更新日期：2015-12-01 00:00:00

abstract：:To quantify metabolite and cation concentrations using NMR spectroscopy, the volumes of intracellular and extracellular spaces must be known. We describe a simple 31P NMR spectroscopic method that employs dimethyl methylphosphonate (DMMP) as a marker of total water space and phenylphosphonate (PPA) as a marker of extr...

journal_title：Magnetic resonance in medicine

authors： Clarke K,Anderson RE,Nédélec JF,Foster DO,Ally A

更新日期：1994-08-01 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：:Specific absorption rate management and excitation fidelity are key aspects of radiofrequency pulse design for parallel transmission at ultra-high magnetic field strength. The design of radiofrequency pulses for multiple channels is often based on the solution of regularized least-squares optimization problems for whi...

journal_title：Magnetic resonance in medicine

authors： Deniz CM,Alon L,Brown R,Sodickson DK,Zhu Y

更新日期：2012-01-01 00:00:00

abstract：:Whole-body NMR imaging antennas (probes) are strongly affected by the inevitable magnetic and controllable dielectric losses. Using a convenient parallelepiped model, the magnetic losses are evaluated. By introducing the "ideal power gain," the best possible antenna performance is delimited as a function of the freque...

journal_title：Magnetic resonance in medicine

authors： Sergiadis G

更新日期：1985-08-01 00:00:00

abstract：PURPOSE:Undiagnosed dehydration compromises health outcomes across many populations. Existing dehydration diagnostics require invasive bodily fluid sampling or are easily confounded by fluid and electrolyte intake, environment, and physical activity limiting widespread adoption. We present a portable MR sensor designed...

journal_title：Magnetic resonance in medicine

authors： Bashyam A,Frangieh CJ,Li M,Cima MJ

更新日期：2020-04-01 00:00:00

abstract：:The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

journal_title：Magnetic resonance in medicine

authors： Zheng S,Xia Y

更新日期：2010-01-01 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：:The soft tissue contrast obtained in fast imaging using rapidly repeated partial saturation sequences is usually based on differences in T1. We describe here an extension of the method which results in the development of clinically useful T2-based contrast. ...

journal_title：Magnetic resonance in medicine

authors： Young IR,Payne JA,Collins AG,Bydder GM

更新日期：1987-04-01 00:00:00

abstract：PURPOSE:To determine the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols used for dynamic contrast-enhanced MRI at 1.5 and 3 T. METHODS:A T1 phantom with 14 samples was imaged at eight centers with a common inversion-recovery spin-echo (IR-SE) protocol and...

journal_title：Magnetic resonance in medicine

authors： Bane O,Hectors SJ,Wagner M,Arlinghaus LL,Aryal MP,Cao Y,Chenevert TL,Fennessy F,Huang W,Hylton NM,Kalpathy-Cramer J,Keenan KE,Malyarenko DI,Mulkern RV,Newitt DC,Russek SE,Stupic KF,Tudorica A,Wilmes LJ,Yankeelov TE

更新日期：2018-05-01 00:00:00

abstract：:Transparent pulses are defined by the property of having no net effect on stationary spins, while selectively nutating and dephasing flowing spins. They are derived from the inverse scattering transform, a nonlinear extension of the inverse Fourier transform. They can be used as presaturation pulses to suppress select...

journal_title：Magnetic resonance in medicine

authors： Buonocore MH

更新日期：1992-04-01 00:00:00

abstract：:The purpose of this study was to evaluate an optimized multislice acquisition technique for oxygen-enhanced MRI of the lung using slice-selective inversion and refocusing pulses in combination with parallel imaging. An inversion recovery HASTE sequence was implemented with respiratory triggering to perform imaging in ...

journal_title：Magnetic resonance in medicine

authors： Dietrich O,Losert C,Attenberger U,Fasol U,Peller M,Nikolaou K,Reiser MF,Schoenberg SO

更新日期：2005-06-01 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：:Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory an...

journal_title：Magnetic resonance in medicine

authors： Aerts HJ,van Riel NA,Backes WH

更新日期：2008-05-01 00:00:00

abstract：:To enhance contrast between flow and static tissue, NMR projective angiographic methods usually require data subtraction, or alternatively the application of special data processing routines such as the "maximum intensity projection" algorithm. We have successfully developed a direct projection method which yields suf...

journal_title：Magnetic resonance in medicine

authors： Matsuda T,Doyle M,Pohost GM

更新日期：1991-04-01 00:00:00