Abstract:
:Longitudinal P-31 relaxation rate enhancements of phosphate groups have been measured at pH 7-7.2 and 310 degrees K on aqueous solutions containing adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi) and some lanthanide complexes (Gd-DOTA, Gd-HPDO3A, Gd-DO3A, Gd-DTPA, Gd-DTPA-BMA). The macrocyclic complexes induce linear enhancements of the relaxation rates of all phosphorus nuclei. For Gd-DOTA and Gd-HPDO3A, the mechanism of the interaction with the P-31 nuclei seems to be of the outer sphere type and a better efficiency is noted for the "neutral" Gd-HPDO3A. A short-lived ternary complex between Gd-DO3A and the phosphorylated metabolites appears to be formed enabling an inner sphere interaction. In solutions containing the open chain complexes, Gd-DTPA and Gd-DTPA-BMA, P-31 relaxation rates of ATP exhibit significant and nonlinear enhancements that are much larger than those observed for PCr and Pi. A ternary complex involving the lanthanide ion, its original chelator, and the ATP molecule is precluded by various experiments which confirm that the lanthanide ion shifts from the original complexes to the ATP phosphate groups.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Vander Elst L,Van Haverbeke Y,Goudemant JF,Muller RNdoi
10.1002/mrm.1910310413subject
Has Abstractpub_date
1994-04-01 00:00:00pages
437-44issue
4eissn
0740-3194issn
1522-2594journal_volume
31pub_type
杂志文章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
doi:10.1002/mrm.23191
更新日期:2012-06-01 00:00:00
abstract::Gliomas are the most common primary brain tumors and the majority are highly malignant, with one of the worst prognoses for patients. Gliomas are characterized by invasive growth into normal brain tissue that makes complete surgical resection and accurate radiotherapy planning extremely difficult. We have performed in...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22163
更新日期:2009-12-01 00:00:00
abstract::It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2...
journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290319
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abstract:PURPOSE:MUSSELS is a one-step iterative reconstruction method for multishot diffusion weighted (msDW) imaging. The current work presents an efficient implementation, termed IRLS MUSSELS, that enables faster reconstruction to enhance its utility for high-resolution diffusion MRI studies. METHODS:The recently proposed M...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2020-06-01 00:00:00
abstract::A single breath-hold 3D cardiac phase resolved steady-state free precession (SSFP) sequence was developed, allowing 3D visualization of the moving coronary arteries. A 3D stack of spirals was acquired continuously throughout the cardiac cycle, and a sliding window reconstruction was used to achieve high temporal resol...
journal_title:Magnetic resonance in medicine
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更新日期:2007-09-01 00:00:00
abstract:PURPOSE:To obtain three-dimensional (3D) MR angiography having high contrast between vessel and stationary background tissue, a novel technique called sliding time of flight (TOF) is proposed. METHODS:The proposed method relies on the property that flow-related enhancement (FRE) is maximized at the blood-entering slic...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25215
更新日期:2015-03-01 00:00:00
abstract::We constructed a device to compress small samples of articular cartilage while the samples were imaged in a 1.5 T imager. With the use of a piezoelectric piston, the device compressed 1-cm-diameter cylindrical samples of articular cartilage (200 microm) at a rate of 2 Hz. Simultaneously, we imaged the samples with a d...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20439
更新日期:2005-05-01 00:00:00
abstract::Fast proton magnetic resonance spectroscopic imaging (MRSI) using a multi-element head-coil array is examined with respect to three aspects: the coil design, the use of an appropriate signal combination method, and the design of the MRSI pulse sequence itself. An eight-element head-coil array has been developed to inc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400204
更新日期:1998-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26361
更新日期:2017-07-01 00:00:00
abstract::This article introduces a novel method named "Parallel Imaging and Noquist in Tandem" (PINOT) for accelerated image acquisition of cine cardiac magnetic resonance imaging. This method combines two prior information formalisms, the SPACE-RIP implementation of parallel imaging and the Noquist method for reduced-data ima...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22696
更新日期:2011-04-01 00:00:00
abstract::Flow measurement methods for functional MRI (fMRI) are desirable as they are more closely tied to neuronal activity than the commonly used blood oxygenation techniques. In this work we introduce a flow-based functional imaging method. The method, called flow enhancement of signal intensity (FENSI), is an extension of ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21325
更新日期:2007-08-01 00:00:00
abstract:PURPOSE:To improve ultrahigh field diffusion-weighted imaging (DWI) in the presence of inhomogeneous transmit B1 field by designing a novel semi-adiabatic single-refocused DWI technique. METHODS:A 180° slice-selective, adiabatic radiofrequency (RF) pulse of 4 ms duration was designed using the adiabatic Shinnar-Le Rou...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25790
更新日期:2016-05-01 00:00:00
abstract::Magnetization transfer imaging (MT) and localized proton spectroscopy (1H-MRS) were utilized in the evaluation of lesions (high signal abnormalities on T2-weighted images) and normal-appearing white matter (NAWM) in multiple sclerosis (MS). Eleven patients with a clinical diagnosis of MS were independently evaluated w...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320303
更新日期:1994-09-01 00:00:00
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
pub_type: 杂志文章
doi:10.1002/mrm.26749
更新日期:2018-02-01 00:00:00
abstract::The potential of quantitative parameter images of the relaxation times T1 and T2, the proton density rho and the apparent diffusion coefficient (ADC) to characterize three different experimental rat brain tumors (F98 glioma, RN6 Schwannoma, and E376 neuroblastoma) was studied. All parameter values, as determined in hi...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910340608
更新日期:1995-12-01 00:00:00
abstract:PURPOSE:To enable highly accelerated distortion-free MRI near metal by separating on- and off-resonance to exploit the redundancy of slice-phase encoding for the dominant on-resonance component. METHODS:Multispectral MRI techniques resolve off-resonance distortions by a combination of limited excitation bins and addit...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26819
更新日期:2018-03-01 00:00:00
abstract::In the pulsed arterial spin labeling (ASL) techniques EPISTAR, PICORE, and FAIR, subtraction of two images in which inflowing blood is first tagged and then not tagged yields a qualitative map of perfusion. An important reason this map is not quantitative is that there is a spatially varying delay in the transit of bl...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910390506
更新日期:1998-05-01 00:00:00
abstract::Phase contrast flow velocity measurements were performed in six healthy volunteers and 30 patients with arteriosclerotic disease. The iliac arteries were investigated in 8 cases and the femoral arteries in 28 cases. In the first 24 patients, 16 evenly distributed data sets were acquired during one cardiac cycle. In th...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340508
更新日期:1995-11-01 00:00:00
abstract::In guinea pigs immunized with myelin basic protein (MBP) in complete Freund's adjuvant, experimental allergic encephalomyelitis (EAE) shows a characteristic clinical and pathological course. This study characterized the proton nuclear magnetic resonance (NMR) properties of the central nervous system prior to the onset...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910050203
更新日期:1987-08-01 00:00:00
abstract::The image intensity in magnetic resonance magnitude images in the presence of noise is shown to be governed by a Rician distribution. Low signal intensities (SNR < 2) are therefore biased due to the noise. It is shown how the underlying noise can be estimated from the images and a simple correction scheme is provided ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340618
更新日期:1995-12-01 00:00:00
abstract::Functional magnetic resonance imaging (fMRI) was conducted to observe the effects of cocaine administration on the physiological fluctuations of fMRI signal in two brain regions. Seven long-term cocaine users with an average age of 32 years and 8 years of cocaine use history were recruited for the study. A T2*-weighte...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/(sici)1522-2594(200001)43:1<45::aid-mrm6>3
更新日期:2000-01-01 00:00:00
abstract:PURPOSE:To optimize and investigate the influence of bipolar gradients for flow suppression in metabolic quantification of hyperpolarized 13 C chemical shift imaging (CSI) of mouse liver at 9.4 T. METHODS:The trade-off between the amount of flow suppression using bipolar gradients and T2* effect from static spins was ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26578
更新日期:2017-11-01 00:00:00
abstract::The utility of a noninvasive steady state susceptibility-contrast MRI technique for continuous measurement of relative cerebral blood volume (rCBV) during global transient ischemia and subsequent hyperemia in a feline ischemia model is demonstrated. The measurements were obtained during a 10-min period of occlusion an...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910350207
更新日期:1996-02-01 00:00:00
abstract::A method is presented that employs the inherent spectral selectivity of the Steady-State Free Precession (SSFP) pulse sequence to provide a spectral band of suppression. At TE = TR/2, SSFP partitions the magnetization into two phase-opposed spectral components. Z-storing one of these components simultaneously further ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20633
更新日期:2005-10-01 00:00:00
abstract::The orientation dependence of the free induction decay (FID) of 1H NMR water signal in ex vivo bovine digital flexor tendon at the native level of hydration is reported. Residual dipolar coupling due to the overall tissue anisotropy produces a 6:1 change in the signal intensity as an angle between the long axis of a s...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20540
更新日期:2005-08-01 00:00:00
abstract::Cortical spreading depression (CSD) was visualized using manganese-enhanced MRI (MEMRI) following topical application of KCl to the exposed rat cortex. MEMRI signal increase in the ipsilateral cortex relative to the contralateral control region was 60 +/- 30% following two KCl applications. MEMRI signal increase for a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20438
更新日期:2005-04-01 00:00:00
abstract:PURPOSE:To use the variable delay multipulse (VDMP) chemical exchange saturation transfer (CEST) approach to obtain clean amide proton transfer (APT) and relayed Nuclear Overhauser enhancement (rNOE) CEST images in the human brain by suppressing the conventional magnetization transfer contrast (MTC) and reducing the di...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25990
更新日期:2016-01-01 00:00:00
abstract:PURPOSE:To evaluate the use of variable flip angle refocusing pulse trains in single-shot three-dimensional gradient and spin-echo (3D-GRASE) to reduce blurring and increase the spatial coverage for high spatial resolution T2 -weighted functional MRI at 7 Tesla. METHODS:Variable flip angle refocusing schemes in 3D-GRA...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.25979
更新日期:2016-09-01 00:00:00
abstract::Proton MRS (1 H MRS) provides noninvasive, quantitative metabolite profiles of tissue and has been shown to aid the clinical management of several brain diseases. Although most modern clinical MR scanners support MRS capabilities, routine use is largely restricted to specialized centers with good access to MR research...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章,评审
doi:10.1002/mrm.27742
更新日期:2019-08-01 00:00:00