Delay and dispersion effects in dynamic susceptibility contrast MRI: simulations using singular value decomposition.

abstract：:There is increasing interest in quantitative T(1) mapping techniques for a variety of applications. Several methods for T(1) quantification have been described. The acquisition of two spoiled gradient-echo data sets with different flip angles allows for the calculation of T(1) maps with a high spatial resolution and a...

journal_title：Magnetic resonance in medicine

authors： Preibisch C,Deichmann R

更新日期：2009-01-01 00:00:00

abstract：:Manganese-enhanced MRI has previously been used for visualization of brain architecture and functional mapping of neural pathways. The present work investigated the potential of manganese-enhanced MRI for noninvasive imaging of salivary glands in living subjects. Marked shortening of T(1) was observed in salivary glan...

journal_title：Magnetic resonance in medicine

authors： Seshadri M,Hoy A

更新日期：2010-09-01 00:00:00

abstract：PURPOSE:To assess the blood-tissue distribution of hyperpolarized (13) C-labeled molecules in vivo. METHODS:Spin-echo experiments with simultaneous acquisition of the free induction decay (FID) signal following the excitation pulse and the spin-echo signal, were used to monitor hyperpolarized [1-(13) C]lactate, [1-(13...

journal_title：Magnetic resonance in medicine

authors： Kettunen MI,Kennedy BW,Hu DE,Brindle KM

更新日期：2013-11-01 00:00:00

abstract：:A technique for noninvasively quantifying the concentration of sodium ((23) Na) ions was applied to the study of ischemic stroke. (23) Na-magnetic resonance imaging techniques have shown considerable potential for measuring subtle changes in ischemic tissue, although studies to date have suffered primarily from poor s...

journal_title：Magnetic resonance in medicine

authors： Wetterling F,Gallagher L,Macrae IM,Junge S,Fagan AJ

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:To develop and evaluate a neural network-based method for Gibbs artifact and noise removal. METHODS:A convolutional neural network (CNN) was designed for artifact removal in diffusion-weighted imaging data. Two implementations were considered: one for magnitude images and one for complex images. Both models we...

journal_title：Magnetic resonance in medicine

authors： Muckley MJ,Ades-Aron B,Papaioannou A,Lemberskiy G,Solomon E,Lui YW,Sodickson DK,Fieremans E,Novikov DS,Knoll F

更新日期：2021-01-01 00:00:00

abstract：:A modified inversion-recovery sequence is introduced which performs subtraction angiography by varying time-of-flight effects of blood flowing into an imaged slab. The selective 180 degrees excitation inverts different regions between measurements to isolate arterial and/or venous blood. On normal human subjects, high...

journal_title：Magnetic resonance in medicine

authors： Nishimura DG,Macovski A,Pauly JM,Conolly SM

更新日期：1987-02-01 00:00:00

abstract：:Three-dimensional spatial-spectral radiofrequency pulses using a stack-of-spirals trajectory can achieve two-dimensional spatial localization and one-dimensional spectral selection simultaneously. These pulses are useful, for example, in reduced field-of-view applications that also require frequency specificity such a...

journal_title：Magnetic resonance in medicine

authors： Deng W,Stenger VA

更新日期：2010-03-01 00:00:00

abstract：PURPOSE:To develop a three-dimensional, free-breathing, late gadolinium enhancement (3D FB-LGE) cardiovascular magnetic resonance (CMR) technique, and to compare it with clinically used two-dimensional breath-hold LGE (2D BH-LGE). METHODS:The proposed 3D FB-LGE method consisted of inversion preparation, inversion dela...

journal_title：Magnetic resonance in medicine

authors： Menon RG,Miller GW,Jeudy J,Rajagopalan S,Shin T

更新日期：2017-04-01 00:00:00

abstract：:ECG-gated cardiac MRI in the mouse is hindered by many technical difficulties in ECG signal recording inside static and variable high magnetic scanner fields. The present study proposes an alternative robust method of acquiring auto-gated cardiac and respiratory cine images in mouse heart. In our approach, a motion sy...

journal_title：Magnetic resonance in medicine

authors： Hiba B,Richard N,Janier M,Croisille P

更新日期：2006-03-01 00:00:00

abstract：:In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit mo...

journal_title：Magnetic resonance in medicine

authors： Nakai T,Rhine WD,Okada T,Stevenson DK,Spielman DM

更新日期：1998-10-01 00:00:00

abstract：PURPOSE:Previous studies have associated low pH in intervertebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo. METHODS:The exchange rate ksw between glycosaminoglycan (GAG) protons and water pr...

journal_title：Magnetic resonance in medicine

authors： Zhou Z,Bez M,Tawackoli W,Giaconi J,Sheyn D,de Mel S,Maya MM,Pressman BD,Gazit Z,Pelled G,Gazit D,Li D

更新日期：2016-12-01 00:00:00

abstract：:Chemical shift-based multipoint water-fat separation methods have been applied in balanced steady-state free precession (bSSFP) sequences because of the high signal-to-noise-ratio (SNR) attainable. In this approach the echo formation is approximated to occur concurrently for both water and fat at an echo time (TE) equ...

journal_title：Magnetic resonance in medicine

authors： Kim H,Pinus AB,Wang J,Murphy PS,Constable RT

更新日期：2007-08-01 00:00:00

abstract：PURPOSE:Simultaneous brain and spinal cord functional MRI is emerging as a new tool to study the central nervous system but is challenging. Poor B0 homogeneity and small size of the spinal cord are principal obstacles to this nascent technology. Here we extend a dynamic shimming approach, first posed by Finsterbusch, b...

journal_title：Magnetic resonance in medicine

authors： Islam H,Law CSW,Weber KA,Mackey SC,Glover GH

更新日期：2019-02-01 00:00:00

abstract：:Keyhole acquisition techniques have been used to reduce image acquisition times primarily in contrast agent studies and via simulation in interventional MRI procedures. More recent simulations have suggested that improved definition of an interventional device [e.g., biopsy needles, radio frequency (RF) electrodes] co...

journal_title：Magnetic resonance in medicine

authors： Hwang KP,Lim J,Wendt M,Merkle E,Lewin JS,Duerk JL

更新日期：1999-09-01 00:00:00

abstract：PURPOSE:To improve the specific absorption rate (SAR) compression model capability in parallel transmission (pTx) MRI systems. METHODS:A k-means clustering method is proposed to group voxels with similar SAR behaviors in the scanned object, providing a controlled upper-bounded estimation of peak local SARs. This k-mea...

journal_title：Magnetic resonance in medicine

authors： Mao X,Bari S,Love DJ,Rispoli JV

更新日期：2021-02-01 00:00:00

abstract：:Follow-up T(1)-weighted 3D gradient-echo MRI (2.35 T) of murine brain in vivo (N = 5) at 120 microm isotropic resolution revealed spatially distinct signal increases 6-48 hr after subcutaneous application of MnCl(2) (20 mg/kg). The effects result from a shortening of the water proton T(1) relaxation time due to the pr...

journal_title：Magnetic resonance in medicine

authors： Watanabe T,Natt O,Boretius S,Frahm J,Michaelis T

更新日期：2002-11-01 00:00:00

abstract：PURPOSE:To assess the risk of radiofrequency (RF)-induced heating in patients with MR-conditional pacemaker (PM) systems, in the presence of another lead abandoned from a previous implant. METHODS:Four commercial pacemaker leads were placed beside a MR-conditional PM system, inside a human trunk simulator. The phantom...

journal_title：Magnetic resonance in medicine

authors： Mattei E,Gentili G,Censi F,Triventi M,Calcagnini G

更新日期：2015-01-01 00:00:00

abstract：:We have demonstrated that echo-planar imaging can be used to produce high-quality snapshot images of the human fetus in utero in a fraction of a second. These images are free of motional artifact or blurring and allow detailed depiction of fetal structures in normal and pathological pregnancies. ...

journal_title：Magnetic resonance in medicine

authors： Stehling MK,Mansfield P,Ordidge RJ,Coxon R,Chapman B,Blamire A,Gibbs P,Johnson IR,Symonds EM,Worthington BS

更新日期：1990-02-01 00:00:00

abstract：PURPOSE:Atherosclerotic carotid plaques can be quantified in vivo by MRI. However, the accuracy in segmentation and quantification of components such as the thin fibrous cap (FC) and lipid-rich necrotic core (LRNC) remains unknown due to the lack of a submillimeter scale ground truth. METHODS:A novel approach was take...

journal_title：Magnetic resonance in medicine

authors： Nieuwstadt HA,Geraedts TR,Truijman MT,Kooi ME,van der Lugt A,van der Steen AF,Wentzel JJ,Breeuwer M,Gijsen FJ

更新日期：2014-07-01 00:00:00

abstract：:Due to the presence of gross magnetic susceptibility artifacts, functional MRI (fMRI) has proved problematic in studies of the human inferior frontal cortex (IFC). There is a strong desire, therefore, to employ techniques that mitigate susceptibility artifacts in the IFC while preserving the imaging parameters of an f...

journal_title：Magnetic resonance in medicine

authors： Wilson JL,Jezzard P

更新日期：2003-11-01 00:00:00

abstract：:Phase-contrast MRI can provide high-resolution angiographic velocity images, especially in conjunction with non-Cartesian k-space sampling. However, acquisitions can be sensitive to errors from artifacts from main magnetic field inhomogeneities and chemical shift from fat. Particularly in body imaging, fat content can...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Wieben O,Samsonov AA

更新日期：2010-06-01 00:00:00

abstract：:In the ongoing quest for faster imaging and higher spatial resolution, several methods have been developed to speed up data acquisition by incorporating prior information about the object being imaged. This study shows that many of these methods can be integrated into a single common equation. The unified framework pr...

journal_title：Magnetic resonance in medicine

authors： Tsao J,Behnia B,Webb AG

更新日期：2001-10-01 00:00:00

abstract：:We present preliminary results for a 3D finite element calculation to evaluate RF penetration in conducting dielectric materials at high field strengths. A tetrahedral mesh is used along with a Coulomb gauge constraint in a finite element method that yields excellent numerical stability at high frequencies. Accuracy i...

journal_title：Magnetic resonance in medicine

authors： Petropoulos LS,Haacke EM,Brown RW,Boerner E

更新日期：1993-09-01 00:00:00

abstract：:Steady-state free precession (SSFP) methods have been very successful due to their high signal and short imaging times. These properties make them good candidates for applications that intrinsically suffer from low signal such as low gamma nuclei imaging. A new chemical shift imaging (CSI) technique based on the SSFP ...

journal_title：Magnetic resonance in medicine

authors： Speck O,Scheffler K,Hennig J

更新日期：2002-10-01 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

authors： Poulin E,Lebel R,Croteau E,Blanchette M,Tremblay L,Lecomte R,Bentourkia M,Lepage M

更新日期：2013-03-01 00:00:00

abstract：:The harmonic phase (HARP) method provides automatic and rapid analysis of tagged magnetic resonance (MR) images for quantification and visualization of myocardial strain. In this article, the development and implementation of a pulse sequence that acquires HARP images in real time are described. In this pulse sequence...

journal_title：Magnetic resonance in medicine

authors： Sampath S,Derbyshire JA,Atalar E,Osman NF,Prince JL

更新日期：2003-07-01 00:00:00

abstract：PURPOSE:Imaging gradients result in the generation of concomitant fields, or Maxwell fields, which are of increasing importance at higher gradient amplitudes. These time-varying fields cause additional phase accumulation, which must be compensated for to avoid image artifacts. In the case of gradient systems employing ...

journal_title：Magnetic resonance in medicine

authors： Weavers PT,Tao S,Trzasko JD,Frigo LM,Shu Y,Frick MA,Lee SK,Foo TK,Bernstein MA

更新日期：2018-03-01 00:00:00

abstract：:Parallel magnetic resonance imaging in k-space such as generalized auto-calibrating partially parallel acquisition exploits spatial correlation among neighboring signals over multiple coils in calibration to estimate missing signals in reconstruction. It is often challenging to achieve accurate calibration information...

journal_title：Magnetic resonance in medicine

authors： Park S,Park J

更新日期：2012-06-01 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

authors： Madore B,Glover GH,Pelc NJ

更新日期：1999-11-01 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

authors： Li SJ,Biswal B,Li Z,Risinger R,Rainey C,Cho JK,Salmeron BJ,Stein EA

更新日期：2000-01-01 00:00:00