Abstract:
:A planar YBa2Cu3Ox (YBCO) coil has been used as a pick-up coil in a nuclear magnetic resonance imager. It was found that the quality factor (Q) of the YBCO coil was greater than its copper counterpart by approaching 50% even in a field of 0.15 T. The Q of the copper coil at 77 K and in a field of 0.15 T was 1200 while that of the YBCO coil under identical conditions was 1700.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Hall AS,Alford NM,Button TW,Gilderdale DJ,Gehring KA,Young IRdoi
10.1002/mrm.1910200218subject
Has Abstractpub_date
1991-08-01 00:00:00pages
340-3issue
2eissn
0740-3194issn
1522-2594journal_volume
20pub_type
杂志文章abstract::The focal underdetermined system solver (FOCUSS) was originally designed to obtain sparse solutions by successively solving quadratic optimization problems. This article adapts FOCUSS for a projection reconstruction MR imaging problem to obtain high resolution reconstructions from angular under-sampled radial k-space ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21202
更新日期:2007-04-01 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
pub_type: 杂志文章
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更新日期:2012-06-01 00:00:00
abstract::T2 relaxation time is a promising MRI parameter for the detection of cartilage degeneration in osteoarthritis. However, the accuracy and precision of the measured T2 may be substantially impaired by the low signal-to-noise ratio of images available from clinical examinations. The purpose of this work was to assess the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2010-01-01 00:00:00
abstract::Applications of fMRI in functional brain imaging are mainly confined to single subject designs, prohibiting the assessment of subject or group by condition interactions (i.e., differential activations) or areas of conjoint activation. In this paper a framework for fMRI group designs, using statistical parametric mappi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910380502
更新日期:1997-11-01 00:00:00
abstract::Current MRI methods for myocardial motion and strain quantification have limited resolution because of Fourier space spectral peak interference. Methods have been proposed to remove this interference in order to improve resolution; however, these methods are clinically impractical due to the prolonged imaging times. I...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22403
更新日期:2010-08-01 00:00:00
abstract:PURPOSE:Waveguide elastography (WGE) combines magnetic resonance elastography (MRE), diffusion tensor imaging (DTI), and anisotropic inversions for a determination of the elastic properties of white matter. Previously, the method evaluated the anisotropic elastic properties of the corticospinal tracts (CSTs) of healthy...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25067
更新日期:2014-12-01 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
pub_type: 杂志文章
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更新日期:2013-10-01 00:00:00
abstract::Magnetic resonance imaging allows numerous k-space sampling schemes such as cartesian, polar, spherical, and other non-rectilinear trajectories. Non-rectilinear MR acquisitions permit fast scan times and can suppress motion artifacts. Still, these sampling schemes may adversely affect the image characteristics due to ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910360617
更新日期:1996-12-01 00:00:00
abstract::Multimodal, biocompatible contrast agents for high magnetic field applications represent a new class of nanomaterials with significant potential for tracking of fluorescence and MR in vitro and vivo. Optimized for high-field MR applications-including biomedical imaging at 21.1 T, the highest magnetic field available f...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22441
更新日期:2010-09-01 00:00:00
abstract::Prospective motion correction methods using an optical system, diffusion-weighted prospective acquisition correction, or a free induction decay navigator have recently been applied to correct for motion in diffusion tensor imaging. These methods have some limitations and drawbacks. This article describes a novel techn...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.23314
更新日期:2012-10-01 00:00:00
abstract::Quantitative diffusion measurements were performed in tumors arising from inoculation of nude mice with two human breast cancer cell lines (MCF7 and T47D) to evaluate the specificity of this technique for characterizing solid tumors. ADC maps were compared to histology and correlated well with gross tumor morphology. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910370417
更新日期:1997-04-01 00:00:00
abstract:PURPOSE:Head motion continues to be a major source of artifacts and data quality degradation in MRI. The goal of this work was to develop and demonstrate a novel technique for prospective, 6 degrees of freedom (6DOF) rigid body motion estimation and real-time motion correction using inductively coupled wireless nuclear...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25001
更新日期:2014-10-01 00:00:00
abstract::In vivo measurements of gadodiamide (Gd-DTPA-BMA) T(1) relaxivity were performed at 4.7 T in injured and normal rat brains. Cerebral lesions were induced in nine rats by a localized freezing method. T(1) maps of the lesions were generated before and after injection of Gd-DTPA-BMA (0.1-0.6 mmol/kg). Samples of normal a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20336
更新日期:2005-01-01 00:00:00
abstract::In this study undersampled projection reconstruction (PR) was used for rapid catheter imaging in the heart, employing steady-state free precession (SSFP) contrast. Active catheters and phased-array coils were used for combined imaging of anatomy and catheter position in swine. Real-time imaging of catheter position wa...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10390
更新日期:2003-02-01 00:00:00
abstract:PURPOSE:Amide-proton transfer (APT) and amine-water proton exchange (APEX) MRI can be viable to map pH-decreasing ischemic regions. However, their exact contributions are unclear. METHODS:We measured APEX- and APT-weighted magnetization transfer ratio asymmetry (denoted as APEXw and APTw), apparent diffusion coefficie...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24639
更新日期:2014-01-01 00:00:00
abstract:PURPOSE:Magnetic susceptibility is a physical property of matter that varies depending on chemical composition and abundance of different molecular species. Interest is growing in mapping of magnetic susceptibility in the human brain using magnetic resonance imaging techniques, but the influences affecting the mapped v...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2017-05-01 00:00:00
abstract::Continuous arterial spin labeling (CASL) was used to obtain an index of cerebral blood flow (ICBF) in the normal mouse brain and in an orthotopic mouse model of human U87 high-grade glioma at 8.5 T. Under the assumption of a constant tissue:blood partition coefficient for water in different tissues, the mean ICBF (n =...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20029
更新日期:2004-05-01 00:00:00
abstract::The protocol for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was adapted for the evaluation of transplanted osteochondral allograft cartilage. Eight patients with focal grade 4 cartilage defects of the femoral condyle were treated with single cylindrical osteochondral allografts. At 1 and 2 years, dGEMRIC i...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/mrm.24419
更新日期:2013-06-01 00:00:00
abstract::Current implementations of coronary artery magnetic resonance angiography (MRA) suffer from limited coverage of the coronary arterial system. Whole-heart coronary MRA was implemented based on a free-breathing steady-state free-precession (SSFP) technique with magnetization preparation. The technique was compared to a ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10653
更新日期:2003-12-01 00:00:00
abstract::The purpose of this study was to determine the value of a blood-pool contrast media (NC100150, Nycomed Imaging (now Amersham Health) Oslo, Norway) for evaluation of venous thrombosis of the deep veins of the pelvis and lower extremities. Twelve patients were prospectively evaluated with conventional X-ray venography (...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章,随机对照试验
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更新日期:2003-11-01 00:00:00
abstract:PURPOSE:Fourier decomposition (FD) is a noninvasive method for assessing ventilation and perfusion-related information in the lungs. However, the technique has a low signal-to-noise ratio (SNR) in the lung parenchyma. We present an approach to increase the SNR in both morphological and functional images. METHODS:The d...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25293
更新日期:2015-05-01 00:00:00
abstract::31P NMR spectroscopy was used to study renal allografts in rats subjected to allograft rejection, cyclosporine toxicity, ischemia, and ureteral obstruction. Parameters of relative peak areas and intracellular pH were accurately distinguished among the different causes of graft dysfunction. Ureteral obstruction was cle...
journal_title:Magnetic resonance in medicine
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更新日期:1987-10-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10165
更新日期:2002-06-01 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
pub_type: 杂志文章
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更新日期:2018-11-01 00:00:00
abstract:PURPOSE:A direct method of imaging neural activity was simulated to determine typical signal sizes. METHODS:An active bidomain finite-element model was used to estimate approximate perturbations in MR phase data as a result of neural tissue activity, and when an external MR electrical impedance tomography imaging curr...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2019-01-01 00:00:00
abstract::The ability to generate in vivo maps of lactate may have significant diagnostic utility in staging and treatment planning of a wide variety of cancers. The double selective multiple quantum filter technique (SelMQC) has been shown to be effective for nonlocalized detection of lactate with little or no interference fro...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21659
更新日期:2008-08-01 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
pub_type: 杂志文章
doi:10.1002/mrm.24318
更新日期:2013-03-01 00:00:00
abstract::The concentration of oxygen within cells is important in many physiological and pathological processes, but such oxygen-dependent phenomena are generally studied as a function of the concentration of extracellular oxygen, due to a lack of suitable methods. Electron parmamagnetic resonance (EPR) oximetric techniques of...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290105
更新日期:1993-01-01 00:00:00
abstract::Compressed sensing has been of great interest to speed up the acquisition of MR images. The k-t group sparse (k-t GS) method has recently been introduced for dynamic MR images to exploit not just the sparsity, as in compressed sensing, but also the spatial group structure in the sparse representation. k-t GS achieves ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2013-04-01 00:00:00
abstract::Precise relaxation time (RT) measurements have been made, with a standard deviation of 3% for T1 and T2 in white matter in normal volunteers. This sets an upper limit to the instrumental random errors (imprecision). Achieving this precision requires careful adjustment and use of the imager. The wide variation in RTs s...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910110307
更新日期:1989-09-01 00:00:00