Abstract:
:The chain dynamics of short-chain perfluoropolyether melts confined in Vycor nanoporous media has been characterized by field cycling nuclear magnetic resonance relaxometry and the dipolar correlation effect. The slowdown of motions under confinement, leading to larger residual dipolar couplings, has been probed by looking at the quotient of stimulated and primary echoes. Using field cycling relaxometry, it has been shown that there is strong evidence of reptation-like motion, even for such short-chain polymers as shown by the frequency and molecular weight dependences of the spin-lattice relaxation time.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Kausik R,Fatkullin N,Hüsing N,Kimmich Rdoi
10.1016/j.mri.2006.11.018subject
Has Abstractpub_date
2007-05-01 00:00:00pages
489-92issue
4eissn
0730-725Xissn
1873-5894pii
S0730-725X(06)00411-5journal_volume
25pub_type
杂志文章abstract::In recent years there has been increasing interest in applying magnetic resonance (MR) techniques in areas of engineering and chemical technology. The science that underpins many of these applications is the physics and chemistry of transport and reaction processes in porous materials. Key to the exploitation of MR me...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(03)00127-9
更新日期:2003-04-01 00:00:00
abstract:OBJECTIVES:To investigate the feasibility of chemical exchange saturation transfer (CEST) MRI in patients with breast carcinomas and possible correlations between magnetization transfer asymmetry (MTRasym) values and histological features, such as tumor grade and the Ki-67 proliferation index. MATERIALS AND METHODS:Ni...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.03.004
更新日期:2019-06-01 00:00:00
abstract::We report initial NMR studies of continuous flow laser-polarized xenon gas, both in unrestricted tubing, and in a model porous media. The study uses Pulsed Gradient Spin Echo-based techniques in the gas-phase, with the aim of obtaining more sophisticated information than just translational self-diffusion coefficients....
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(03)00156-5
更新日期:2003-04-01 00:00:00
abstract::Current density imaging (CDI) has been shown to be a feasible method to map spatial distribution of electric currents through bone structures and for studying osteoporosis and bone fracture models. For the osteoporosis model, bone sample was moistened in a solution of a sodium salt of ethylendiamintetraacetic acid (ED...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(97)00038-6
更新日期:1997-01-01 00:00:00
abstract::Functional T1ρ mapping has been proposed as a method to assess pH and metabolism dynamics in the brain with high spatial and temporal resolution. The purpose of this work is to describe and evaluate a variant of the spin-locked echo-planar imaging sequence for functional T1ρ mapping at 3T. The proposed sequence rapidl...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.07.010
更新日期:2014-11-01 00:00:00
abstract:OBJECTIVES:The objectives of this study were to develop protocols that measure abdominal fat and calf muscle lipids with magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), respectively, at 3 T and to examine the correlation between these parameters and insulin sensitivity. MATERIALS AND METHOD...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.06.006
更新日期:2008-02-01 00:00:00
abstract::In vivo temporal EPR imaging was conducted on the brain of rats that received one of two kinds of blood-brain barrier-permeable nitroxide radicals via the tail vein-one is a water-soluble 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (hydroxymethyl-PROXYL); and the other is a non-water-soluble 3-methoxycarbony...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(02)00491-5
更新日期:2002-04-01 00:00:00
abstract::Pulsed field gradient (PFG) nuclear magnetic resonance (NMR) and microimaging experiments have been performed to study the diffusion of liquid alkanes into a variety of semicrystalline polyethylene (PE) samples. The results highlight the importance of the crystalline phase in controlling the diffusion process in terms...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00032-0
更新日期:1998-06-01 00:00:00
abstract:PURPOSE:Diffusional kurtosis imaging (DKI) is sensitive to the effects of signal noise due to strong diffusion weightings and higher order modeling of the diffusion weighted signal. A simple noise correction scheme is proposed to remove the majority of the noise bias in the estimated diffusional kurtosis. METHODS:Weig...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.08.028
更新日期:2015-01-01 00:00:00
abstract::The goal of this study was to develop and evaluate high-resolution magnetic resonance spectroscopic imaging (MRSI) utilizing the gains in signal-to-noise ratio (SNR) provided by combining higher magnetic field with high-sensitivity phased-array (PA) coils. We investigated the maximum improvement in spatial resolution ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.10.019
更新日期:2006-01-01 00:00:00
abstract::A technique for obtaining quantitative longitudinal saturation/porosity profiles of rock cores which are longer than the NMR coil has been developed. The slice-selected experiment uses a prefocused pulse in conjunction with a magnetic field gradient for the localization and a CPMG sequence to sample the data. A variet...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)91547-4
更新日期:1994-01-01 00:00:00
abstract::Functional magnetic resonance imaging (fMRI) was used to investigate the spatial distribution of cortical activation in frontal and parietal lobes during auditory and visual oddball tasks in 10 healthy subjects. The purpose of the study was to compare activation within auditory and visual modalities and identify commo...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00128-4
更新日期:2000-06-01 00:00:00
abstract::High-resolution magnetic resonance imaging using dedicated high-field radiofrequency micro-coils at 16.4 T (700 MHz) was investigated. Specific solenoid coils primarily using silver and copper as conductors with enamel and polyurethane coatings were built to establish which coil configuration produces the best image. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.04.027
更新日期:2012-10-01 00:00:00
abstract::We have extended the utility of NMR as a technique to probe porous media structure over length scales of approximately 100-2000 microm by using the spin 1/2 noble gas 129Xe imbibed into the system's pore space. Such length scales are much greater than can be probed with NMR diffusion studies of water-saturated porous ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00247-8
更新日期:2001-04-01 00:00:00
abstract::Microscopic magnetic resonance elastography is a high-resolution method for visualizing shear waves and assessing the biomechanical viscoelastic properties of small biological samples. In this work, we used error propagation to develop a simple analytical model that relates the signal-to-noise ratio of MR magnitude im...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.09.040
更新日期:2007-01-01 00:00:00
abstract:PURPOSE:Lower fat fraction (FF) in brown adipose tissue (BAT) than white adipose tissue (WAT) has been exploited using Dixon-based Magnetic Resonance Imaging (MRI) to differentiate these tissues in rodents, human infants and adults. We aimed to determine whether an optimal FF threshold could be determined to differenti...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.04.013
更新日期:2018-09-01 00:00:00
abstract::Phantoms for evaluation of nuclear magnetic resonance (NMR) imaging systems were made from water-based agarose gels, according to a standard procedure herein described. Copper sulfate (CuSO4) was included in the gels to further affect their proton relaxation characteristics. The proton relaxation rates of each batch o...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(86)91068-4
更新日期:1986-01-01 00:00:00
abstract:PURPOSE:Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating moto...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.02.015
更新日期:2015-06-01 00:00:00
abstract::The physiological parameters measured in the tracer kinetics modeling of data from a dynamic contrast-enhanced magnetic resonance (MR) breast exam (blood flow-extraction fraction product [FE], volume of the extracellular extravascular space [Ve], and blood volume [Vb]) may enable non-invasive diagnosis of breast cance...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00130-1
更新日期:1998-11-01 00:00:00
abstract::High density barium sulphate suspension was investigated as an oral contrast on MRI. On 30 consecutive subjects, the stomach (in all cases) and the two first portions of the duodenum (in 21 cases) were filled with the suspension. This oral contrast behaved as a negative contrast, being hypointense on all pulse sequenc...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90019-i
更新日期:1991-01-01 00:00:00
abstract::Until recently, NMR imaging with intermolecular multiple-quantum coherences (iMQCs) has been based on the acquisition of a single echo. In vivo studies of iMQC image contrast would greatly benefit from a method that could acquire several orders of quantum coherence during the same acquisition. This would enable compar...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.10.019
更新日期:2004-12-01 00:00:00
abstract::A new application of the stimulated echo pulse sequence is presented that permits the elucidation of molecular order and dynamics in a time scale between about 100 microseconds and the spin-lattice relaxation time. The technique exploits the influence of dipolar coupling on the quotient of the stimulated and primary e...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00172-5
更新日期:1996-01-01 00:00:00
abstract::A new pulse sequence for estimating cerebral blood flow called UNFAIR, which uses a combination of sequential hyperbolic secant preparatory pulses, is introduced. This sequence is based on the same generalized conditions as previously introduced inversion recovery techniques except that the spins in the image slice of...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00353-0
更新日期:1997-01-01 00:00:00
abstract::Diffusion-weighted imaging (DWI) is a relatively new magnetic resonance imaging (MRI) technique that can be used to probe the microenvironment of water. Contrast in DWI depends on properties different from traditional T1 and T2 contrast, and is derived form the translational motion of water molecules. Since it is reas...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
doi:10.1016/0730-725x(95)02036-s
更新日期:1995-01-01 00:00:00
abstract::Prostate MRI is an important tool to diagnose and characterize cancer. High local sensitivity and good parallel imaging performance are of paramount importance for diagnostic quality and efficiency. The purpose of this work was to evaluate stacked resonators as part of a surface receiver array for prostate MRI at 3 Te...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.07.010
更新日期:2018-11-01 00:00:00
abstract:PURPOSE:To evaluate the application of high-resolution MRI methodology for characterizing the fluid velocity field and evaluate fluid shear field within a simplified in vitro model of a bone-implant interface. MATERIALS AND METHODS:The study used a specific micromotion canine bone implant that has been used for over a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.11.001
更新日期:2006-06-01 00:00:00
abstract::Left ventricle (LV) segmentation plays an important role in the diagnosis of cardiovascular diseases. The cardiac contractile function can be quantified by measuring the segmentation results of LVs. Fully convolutional networks (FCNs) have been proven to be able to segment images. However, a large number of annotated ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.08.004
更新日期:2020-02-01 00:00:00
abstract::The relative value of two different MRI procedures for the assessment of infratentorial extension in multiple sclerosis (MS) was studied. Multislice spin-echo techniques were used overall. Procedure A consisted of parasagittal T1-weighted images (500/30) and axial T2-weighted images (2500/30, 2500/120). Procedure B co...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(89)90547-x
更新日期:1989-05-01 00:00:00
abstract::An NMR technique is described which allows the observation of ionic charge carriers moving in the electric field within a porous system saturated with electrolyte solution. This method, which was recently developed in our laboratory, gives experimental access to the study of electric transport in disordered media on a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00267-3
更新日期:2001-04-01 00:00:00
abstract::The successful use of magnetic resonance imaging (MRI) of a moldic fossil dicynodont from the Permian aeolian Hopeman Sandstone Formation of Elgin, Scotland, UK, provides paleontologists with a nondestructive technique for examining fossils preserved in this fashion. For large moldic fossils, medical scanners such as ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2003.09.006
更新日期:2004-02-01 00:00:00