Abstract:
PURPOSE:Vulnerable atherosclerotic plaques are structurally weak and prone to rupture, presumably due to local oxidative stress. Redox active iron is linked to oxidative stress and the aim of this study was to investigate the distribution of Fe(III) in carotid plaques and its relation to vulnerability for rupture. METHODS:Atherosclerotic plaques from 10 patients (three asymptomatic and seven symptomatic) were investigated. Plaque vulnerability was classified using ultrasound and immunohistochemistry and correlated to Fe(III) measured by electron paramagnetic resonance spectroscopy. RESULTS:Large intra-plaque Fe(III) variations were found. Plaques from symptomatic patients had a higher Fe(III) concentration as compared with asymptomatic plaques (0.36 ± 0.21 vs. 0.06 ± 0.04 nmol Fe(III)/mg tissue, P < 0.05, in sections adjoining narrowest part of the plaques). All but one plaque from symptomatic patients showed signs of cap rupture. No plaque from asymptomatic patients showed signs of cap rupture. There was a significant increase in cap macrophages in plaques from symptomatic patients compared with asymptomatic patients (31 ± 11% vs. 2.3 ± 2.3%, P < 0.01). CONCLUSION:Fe(III) distribution varies substantially within atherosclerotic plaques. Plaques from symptomatic patients had significantly higher concentrations of Fe(III), signs of cap rupture and increased cap macrophage activity.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Gustafsson H,Hallbeck M,Norell M,Lindgren M,Engström M,Rosén A,Zachrisson Hdoi
10.1002/mrm.24687subject
Has Abstractpub_date
2014-02-01 00:00:00pages
885-92issue
2eissn
0740-3194issn
1522-2594journal_volume
71pub_type
杂志文章abstract:PURPOSE:Phosphorus spectroscopy (31 P-MRS) is a proven method to probe cardiac energetics. Studies typically report the phosphocreatine (PCr) to adenosine triphosphate (ATP) ratio. We focus on another 31 P signal: inorganic phosphate (Pi), whose chemical shift allows computation of myocardial pH, with Pi/PCr providing ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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abstract:PURPOSE:Gradient imperfections remain a challenge in MRI, especially for sequences relying on long imaging readouts. This work aims to explore image reconstruction based on k-space trajectories predicted by an impulse response model of the gradient system. THEORY AND METHODS:Gradient characterization was performed twi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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abstract::Human intervertebral discs were investigated by 1H NMR in vitro. The measured parameters of samples differently located in discs give the "maps" of discs. The spin-lattice relaxation-time maps show similar structure to dry matter and bound water maps, which might mean the future possibility to detect certain disc proc...
journal_title:Magnetic resonance in medicine
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abstract:PURPOSE:To investigate the influence of transcytolemmal water exchange on estimates of tissue microstructural parameters derived from diffusion MRI using conventional PGSE and IMPULSED methods. METHODS:Computer simulations were performed to incorporate a broad range of intracellular water life times τin (50-∞ ms), cel...
journal_title:Magnetic resonance in medicine
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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
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更新日期:2016-04-01 00:00:00
abstract::Successful radiofrequency (RF) thermal ablation was performed on VX2 tumors implanted in 23 rabbit livers under magnetic resonance (MR) guidance using a C-arm-shaped low-field 0.2 T system. RF application and immediate postprocedure MRI of all animals was performed [T2-weighted, turbo short tau inversion recovery (STI...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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abstract::The purpose of this study is to examine the usefulness of histogram analysis combined with vessel size index (VSI) magnetic resonance imaging for the specific characterization of brain tumor microvasculature in a panel of six volume-matched glioma xenografts. Using a simple descriptive histogram analysis, significant ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2011-03-01 00:00:00
abstract:PURPOSE:Either SENSE+CG or POCS-ICE methods can be used to correct for motion-induced phase errors in navigator-free multishot diffusion imaging. SENSE+CG has the advantage of a fast convergence, however, occasionally the convergence can be unstable, thus degrading the image quality. POCS-ICE has a stable convergence a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2017-07-01 00:00:00
abstract::For protons diffusing among a system of magnetic particles, the process by which initial phase coherence is lost depends substantially on particle size. In this article, evidence for three dephasing mechanisms is presented: an incremental process at small particle sizes (motional averaging regime), a discrete process ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2011-12-01 00:00:00
abstract:PURPOSE:This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. METHODS:Correlation imaging is a high-speed MRI framework in ...
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更新日期:2015-12-01 00:00:00
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更新日期:2011-06-01 00:00:00
abstract:PURPOSE:To develop a novel, simultaneous multislice reconstruction method that exploits Hankel subspace learning (SMS-HSL) for aliasing separation in the slice direction. METHODS:An SMS signal model with the Hankel-structured matrix was proposed. To efficiently suppress interslice leakage artifacts from a signal subsp...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.26527
更新日期:2017-10-01 00:00:00
abstract::A lactate editing sequence based on the use of spin-locking pulses with surface coils is described. The sequence retains more than 90% of the available lactate magnetization and suppresses at least 95% of the lipid signal in a single scan and ca. 99.5% after a simple two step cycle. The technique allows simultaneous o...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:1993-03-01 00:00:00
abstract::Accelerated magnetic resonance imaging techniques reduce signal acquisition time by undersampling k-space. A fundamental problem in accelerated magnetic resonance imaging is the recovery of quality images from undersampled k-space data. Current state-of-the-art recovery algorithms exploit the spatial and temporal stru...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24524
更新日期:2013-09-01 00:00:00
abstract::A method is described for multislice imaging by means of rf pulses which contain a multifrequency excitation spectrum. These pulses label each slice by an individual signal phase and allow the separation of the signals from all the slices by subsequent add/subtract procedures. The image sensitivity corresponds to the ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910060315
更新日期:1988-03-01 00:00:00
abstract::Genetically engineered mouse models provide enormous potential for investigation of the underlying mechanisms of atherosclerotic disease, but noninvasive imaging methods for analysis of atherosclerosis in mice are currently limited. This study aimed to demonstrate the feasibility of MRI to noninvasively visualize athe...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10500
更新日期:2003-07-01 00:00:00
abstract:PURPOSE:To investigate the feasibility of estimating calibration constants (K and T2o ) in vivo for converting whole-blood T2 to blood hemoglobin oxygen saturation (HbO2 ) according to the Luz-Meiboom model, 1/T2=1/T2o+K(1-HbO2)2, where K and T2o are relaxivity and transverse relaxation time of fully saturated blood, r...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.26885
更新日期:2018-04-01 00:00:00
abstract::With the advent of breath-hold MR cardiac imaging techniques, the minimization of TR and TE for oblique planes has become a critical issue. The slew rates and maximum currents of gradient amplifiers limit the minimum possible TR and TE by adding dead-periods to the pulse sequences. We propose a method of designing gra...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320613
更新日期:1994-12-01 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
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doi:10.1002/mrm.10567
更新日期:2003-09-01 00:00:00
abstract:PURPOSE:To develop and evaluate a free-breathing chemical-shift-encoded (CSE) spoiled gradient-recalled echo (SPGR) technique for whole-heart water-fat imaging at 3 Tesla (T). METHODS:We developed a three-dimensional (3D) multi-echo SPGR pulse sequence with electrocardiographic gating and navigator echoes and evaluate...
journal_title:Magnetic resonance in medicine
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更新日期:2014-09-01 00:00:00
abstract::Multiple images acquired simultaneously from an array of surface coils can be combined to give a composite image with an improved signal-to-noise ratio (SNR) and a large field of view. The composite images' SNR can be optimized by taking advantage of noise correlations between coils and phase shifts induced by surface...
journal_title:Magnetic resonance in medicine
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更新日期:2020-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
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更新日期:2005-07-01 00:00:00
abstract::Kinetic analysis with mathematical models has become increasingly important to quantify physiological parameters in computed tomography (CT), positron emission tomography (PET), and dynamic contrast-enhanced MRI (DCE-MRI). The modified Kety/Tofts model and the graphical (Patlak) model have been widely applied to DCE-M...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22819
更新日期:2011-09-01 00:00:00
abstract::Dynamic contrast-enhanced MRI using gadolinium or manganese provides unique characterization of myocardium and its pathology. In this study, an electrocardiography (ECG) triggered saturation recovery Look-Locker method was developed and validated for fast cardiac T(1) mapping in small animal models. By sampling the in...
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更新日期:2010-11-01 00:00:00
abstract:PURPOSE:To develop and evaluate a method for volumetric contrast-enhanced MRI of the liver, with high spatial and temporal resolutions, for combined dynamic imaging and MR angiography (MRA) using a single injection of contrast agent. METHODS:An interleaved variable density (IVD) undersampling pattern was implemented i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25195
更新日期:2015-03-01 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:PURPOSE:A MR thermometry (MRT) method with field monitoring is proposed to improve the measurement of small temperature variations induced in brain MRI exams. METHODS:MR thermometry experiments were performed at 7 Tesla with concurrent field monitoring and RF heating. Images were reconstructed with nominal k-space tra...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.28501
更新日期:2021-03-01 00:00:00
abstract:PURPOSE:To test the feasibility of using the SPICE (SPectroscopic Imaging by exploiting spatiospectral CorrElation) technique, which uses the partial separability of spectroscopic data, for high resolution hyperpolarized (HP) 13 C spectroscopic imaging. METHODS:Numerical simulations were performed to investigate the i...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.27061
更新日期:2018-08-01 00:00:00
abstract::Phosphorus NMR can measure myocardial tissue pH from the chemical shift of inorganic phosphate (Pi) in isolated buffer-perfused hearts, but in vivo the Pi peak originating from the myocardium is obscured by the resonance of 2,3-diphosphoglycerate (DPG) in the blood, making pH difficult to determine. Taking advantage o...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910170209
更新日期:1991-02-01 00:00:00