Abstract:
:The cytosol of intact human red blood cells was loaded with 28.1 +/- 3.4 mM of dysprosium DTPA-BMA using a hypoosmotic technique. When loaded cells were diluted with saline and control cells to give an average dysprosium concentration of 3.3 +/- 0.5 mM, the transverse relaxation rate constants R(*)(2) and R(2) increased. R(*)(2) increased from 7.5 +/- 0.9 sec(-1) to 356 +/- 50 sec(-1), and R(2) increased from 7.4 +/- 0.7 sec(-1) to 148 +/- 40 sec(-1). After lysing, R(*)(2) was 6.0 +/- 0.6 sec(-1) in the control and 13.4 +/- 1.5 sec(-1) in the mixture; R(2) was 6.4 +/- 1.1 sec(-1) and 9.8 +/- 2.4 sec(-1), respectively. Thus, the relaxivity effects were enhanced by sequestration of the dysprosium within intact red cells, and this effect was lost after lysis. At a circulating whole-blood concentration of 0.81 +/- 0.15 mM in rats, the liver signal intensity dropped 29.9% +/- 3.7% and kidney signal intensity dropped 19.4% +/- 8.7%. Dysprosium-loaded cells might be useful in the study of perfusion and tissue blood volume.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Johnson KM,Tao JZ,Kennan RP,Gore JCdoi
10.1002/mrm.1122subject
Has Abstractpub_date
2001-05-01 00:00:00pages
920-3issue
5eissn
0740-3194issn
1522-2594pii
10.1002/mrm.1122journal_volume
45pub_type
杂志文章abstract::An improved double quantum coherence (DQC) filter for the selective in vivo detection of glutathione (GSH) in the human brain at 1.5 Tesla is presented. The goal was to minimize contamination of the DQC-filtered GSH signal at 2.9 ppm with contributions arising from GABA. The modification consists of tailoring the freq...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1094
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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
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abstract::A 3.0 Tesla, 0.80-m bore magnet replaced our previous 1.9 Tesla, 0.76-m magnet. The 3.0 Tesla replacement magnet had a dipole moment of 1.7 with respect to that of the 1.9 Tesla magnet. The pre-existing cylindrically symmetric passive steel shielding was modified to confine the fringe fields of the replacement magnet ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910290319
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abstract::This study characterizes gains in sensitivity and spectral resolution of proton echo-planar spectroscopic imaging (PEPSI) with increasing magnetic field strength (B(0)). Signal-to-noise ratio (SNR) per unit volume and unit time, and intrinsic linewidth (LW) of N-acetyl-aspartate (NAA), creatine (Cr), and choline (Cho)...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21067
更新日期:2006-12-01 00:00:00
abstract:PURPOSE:Magnetic resonance imaging of humans at high magnetic field strengths is strongly influenced by the interference of the radiofrequency (RF) electromagnetic field and the body. To minimize this effect, multiple RF sources could be used. A novel setup (called multimode, coaxial waveguide) is proposed that facilit...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.24807
更新日期:2014-04-01 00:00:00
abstract::Electron Spin Echo Envelope Modulation (ESEEM) data are reported for three gadolinium (III) chelates, Gd-EDTA, Gd-DTPA, and Gd-TTHA, in frozen D2O/CH3OD glasses. This series includes Gd-DTPA, an MRI contrast agent that is in clinical use. Three-pulse electron spin echo modulation patterns can be modeled to yield geome...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910290414
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abstract::It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...
journal_title:Magnetic resonance in medicine
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abstract::The mechanics of the macrocirculation are examined as a basis for imaging blood flow within the system. The macrocirculation is defined as that part of the circulation in which inertial forces are not negligible compared to viscous forces and as such in human subjects comprises the heart and large blood vessels. Becau...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910140204
更新日期:1990-05-01 00:00:00
abstract::A receive-only phased-array coil was designed to image the lower extremities. The array consists of four volume coils placed on two cylindrical formers. The coil array has the ability to image both legs simultaneously over a 40 cm longitudinal field of view (FOV). Experiments using phantoms show an increase in signal-...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.10712
更新日期:2004-03-01 00:00:00
abstract:PURPOSE:To develop a framework for respiratory motion-corrected 3D whole-heart water/fat coronary MR angiography (CMRA) at 3T with reduced and predictable scan time. METHODS:A 3D dual-echo acquisition and respiratory motion-corrected reconstruction framework for water/fat CMRA imaging was developed. The acquisition se...
journal_title:Magnetic resonance in medicine
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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
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更新日期:2013-10-01 00:00:00
abstract::Frequency-modulated (FM) pulses have practical advantages for spin-echo experiments, such as the ability to produce a broadband pi rotation, with an inhomogeneous radiofrequency (RF) field. However, such use leads to a nonlinear phase of the transverse magnetization, which is why FM pulses like the hyperbolic secant (...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.21822
更新日期:2009-01-01 00:00:00
abstract:PURPOSE:Conventional fat/water separation techniques require that patients hold breath during abdominal acquisitions, which often fails and limits the achievable spatial resolution and anatomic coverage. This work presents a novel approach for free-breathing volumetric fat/water separation. METHODS:Multiecho data are ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.26392
更新日期:2017-08-01 00:00:00
abstract::Myocardial MR first-pass perfusion time courses are contaminated by signals from the ventricles (spillover) as a consequence of partial volume effects and motion. An early increase in the signal intensity from the myocardium is an indicator of contamination. This contamination leads to under- or overestimation of perf...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.20015
更新日期:2004-04-01 00:00:00
abstract::High polarization of nuclear spins in liquid state through hyperpolarized technology utilizing dynamic nuclear polarization has enabled the direct monitoring of (13)C metabolites in vivo at a high signal-to-noise ratio. Acquisition time limitations due to T(1) decay of the hyperpolarized signal require accelerated ima...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.22233
更新日期:2010-02-01 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...
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doi:10.1002/mrm.1910380502
更新日期:1997-11-01 00:00:00
abstract::A birdcage coil possesses various intrinsic resonant modes. One of the modes produces sinusoidal current distribution around the rung elements of the birdcage and generates a highly uniform B(1) field in the transverse plane. Another mode is the end-ring resonant mode, in which there are no currents in the rungs of th...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200010)44:4<633::aid-mrm18>3.0.c
更新日期:2000-10-01 00:00:00
abstract:PURPOSE:To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. METHODS:3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisit...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.27540
更新日期:2019-03-01 00:00:00
abstract::In several applications, MRI is used to monitor the time behavior of the signal in an organ of interest; e.g., signal evolution because of physiological motion, activation, or contrast-agent accumulation. Dynamic applications involve acquiring data in a k-t space, which contains both temporal and spatial information. ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199911)42:5<813::aid-mrm1>
更新日期:1999-11-01 00:00:00
abstract:PURPOSE:Application of phase rotation to the STRESS (=STEAM+PRESS) localization scheme, to shorten echo time, minimize J-coupling dephasing and estimate B1+ inhomogeneity. STRESS (=STEAM + PRESS) simultaneously refocuses and acquires the double spin echo (SE123 ) and stimulated echo (STE- ) pathways, combining PRESS-li...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.26911
更新日期:2018-05-01 00:00:00
abstract:PURPOSE:To enable fast and flexible high-resolution four-dimensional (4D) MRI of periodic thoracic/abdominal motion for motion visualization or motion-corrected imaging. METHODS:We proposed a Cartesian three-dimensional k-space sampling scheme that acquires a random combination of k-space lines in the ky/kz plane. A p...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.26406
更新日期:2017-08-01 00:00:00
abstract:PURPOSE:To systematically evaluate the dependence of intravoxel-incoherent-motion (IVIM) parameters on the b-value threshold separating the perfusion and diffusion compartment, and to implement and test an algorithm for the standardized computation of this threshold. METHODS:Diffusion weighted images of the upper abdo...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.25506
更新日期:2015-11-01 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
pub_type: 杂志文章
doi:10.1002/mrm.25725
更新日期:2016-04-01 00:00:00
abstract::Localized 7Li MR point-resolved spectroscopy (PRESS) was developed as a technique to measure lithium (Li) concentration in rat brain in vivo. Localized 7Li spectra could be obtained at 4.7 T in a 0.7-ml voxel in rat brain over the entire therapeutic range of serum Li for humans. Localized 7Li spin-lattice (T1) and spi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20112
更新日期:2004-07-01 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
pub_type: 杂志文章
doi:10.1002/mrm.24779
更新日期:2014-03-01 00:00:00
abstract:PURPOSE:To demonstrate the feasibility of imaging the first passage of a bolus of hyperpolarized (13)C urea through the rodent heart using flow-sensitizing gradients to reduce signal from the blood pool. METHODS:A flow-sensitizing bipolar gradient was optimized to reduce the bright signal within the cardiac chambers, ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25713
更新日期:2016-04-01 00:00:00
abstract::We report the synthesis and characterization of polyvinyl alcohol (PVA) embolic particles modified with a clinically approved magnetic resonance (MR) contrast agent. PVA particles are used during transcatheter arterial embolization (TAE) procedures and this minimally invasive technique is a widely employed treatment f...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21518
更新日期:2008-04-01 00:00:00
abstract::An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910350116
更新日期:1996-01-01 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
pub_type: 杂志文章
doi:10.1002/mrm.21575
更新日期:2008-05-01 00:00:00
abstract::Magnetic resonance imaging measurements of the apparent rate of water diffusion in tumors are sensitive to variations in tissue cellularity, which have been shown useful for characterizing tumors and their responses to treatments. However, because of technical limitations on most MRI systems, conventional pulse gradie...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21793
更新日期:2009-04-01 00:00:00