Experimental approaches to image localized human 31P NMR spectroscopy.

abstract：:Fucose is believed to be a marker for cancer that may be detectable by the 2D proton NMR (COSY) of human plasma. However, the COSY technique is time consuming and prone to error. These problems may be alleviated by using the SUPERCOSY pulse sequence; this technique shows that there are many other cross peaks in the re...

journal_title：Magnetic resonance in medicine

authors： Phillips PS,Herring FG

更新日期：1990-07-01 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：:Measurement of myocardial and brain perfusion when using exogenous contrast agents (CAs) such as gadolinium-DTPA (Gd-DTPA) and MRI is affected by the diffusion of water between compartments. This water exchange may have an impact on signal enhancement, or, equivalently, on the longitudinal relaxation rate, and could t...

journal_title：Magnetic resonance in medicine

authors： Larsson HB,Rosenbaum S,Fritz-Hansen T

更新日期：2001-08-01 00:00:00

abstract：PURPOSE:Real-time assessment of ventricular volumes requires high acceleration factors. Residual convolutional neural networks (CNN) have shown potential for removing artifacts caused by data undersampling. In this study, we investigated the ability of CNNs to reconstruct highly accelerated radial real-time data in pat...

journal_title：Magnetic resonance in medicine

authors： Hauptmann A,Arridge S,Lucka F,Muthurangu V,Steeden JA

更新日期：2019-02-01 00:00:00

abstract：:The integrated T(1)-T(2) characteristics of rat brain and trigeminal nerve water were studied in vivo using a rapid method for acquiring a series of images that depend on T(1) and T(2) relaxation times. Gray matter regions showed only one signal component in both the T(1) and T(2) domains. Trigeminal nerve, however, w...

journal_title：Magnetic resonance in medicine

authors： Does MD,Gore JC

更新日期：2002-02-01 00:00:00

abstract：:Assuming that the SSFP magnetization response maintains a steady state which is periodic in the presence of diffusion, we can solve for the diffusion effect in such sequences. Formulating a Fourier series decomposition solution to the Bloch-Torrey equation and imposing the steady-state condition, analytical expression...

journal_title：Magnetic resonance in medicine

authors： Carney CE,Wong ST,Patz S

更新日期：1991-06-01 00:00:00

abstract：PURPOSE:To design short parallel transmission (pTx) pulses for excitation of arbitrary three-dimensional (3D) magnetization patterns. METHODS:We propose a joint optimization of the pTx radiofrequency (RF) and gradient waveforms for excitation of arbitrary 3D magnetization patterns. Our optimization of the gradient wav...

journal_title：Magnetic resonance in medicine

authors： Davids M,Schad LR,Wald LL,Guérin B

更新日期：2016-10-01 00:00:00

abstract：:High-order radiofrequency transmitter coils are described that permit, in the context of NMR imaging, a knowledgeable trade-off between coil complexity and the degree of inhomogeneity over a specified volume of space. A mathematical formulation of high-order coils is developed for an axially symmetric polarizing dc fi...

journal_title：Magnetic resonance in medicine

authors： Sotgiu A,Hyde JS

更新日期：1986-02-01 00:00:00

abstract：:The dependence of 1/T1 on the magnetic field strength (the relaxation dispersion) has been measured at 37 degrees C on autopsy samples of human brain gray and white matter at field strengths corresponding to proton Larmor frequencies between 10 kHz and 50 MHz (0.0002-1.2 T). Additional measurements of 1/T1 and 1/T2 ha...

journal_title：Magnetic resonance in medicine

authors： Fischer HW,Rinck PA,Van Haverbeke Y,Muller RN

更新日期：1990-11-01 00:00:00

abstract：:Quantification of cerebral blood flow using QUIPSSII pulsed arterial spin labeling requires that the QUIPSS saturation delay TI1 is shorter than the natural temporal bolus width. Yet the duration of the bolus of tagged spins entering the region of interest varies during vasoactive stimuli such as gaseous challenges or...

journal_title：Magnetic resonance in medicine

authors： Villien M,Chipon E,Troprès I,Bouvier J,Cantin S,Chechin D,Le Bas JF,Krainik A,Warnking JM

更新日期：2013-06-01 00:00:00

abstract：PURPOSE:Preclinical imaging of myocardial blood flow (MBF) can elucidate molecular mechanisms underlying cardiovascular disease. We compared the repeatability and variability of two methods, first-pass MRI and arterial spin labeling (ASL), for imaging MBF in mice. METHODS:Quantitative perfusion MRI in mice was perform...

journal_title：Magnetic resonance in medicine

authors： Naresh NK,Chen X,Moran E,Tian Y,French BA,Epstein FH

更新日期：2016-06-01 00:00:00

abstract：:Partially parallel imaging strategies such as SMASH, SENSE, and PILS rely on the sensitivity distribution of phased array RF coils to reduce MRI imaging time. Using an N-element phased array, these techniques allow maximum accelerations, L, such that L < or = N, with acceleration defined as the factor by which scan ti...

journal_title：Magnetic resonance in medicine

authors： Bankson JA,Wright SM

更新日期：2002-04-01 00:00:00

abstract：:This work presents a method applied to the design of short self-shielded gradient coils of cylindrical geometry. The method uses a hybrid technique that combines the simulated annealing and target field methods to optimize the standard stream functions. The optimized stream functions were parameterized using a few deg...

journal_title：Magnetic resonance in medicine

authors： Tomasi D

更新日期：2001-03-01 00:00:00

abstract：PURPOSE:To develop and validate closed form mathematical expressions that predict the optimal contrast agent concentration for the maximum T1-weighted spoiled gradient echo (SGRE) signal. THEORY AND METHODS:Gadolinium and iron-based contrast agents can have significant transverse relaxivity that leads to signal dropou...

journal_title：Magnetic resonance in medicine

authors： Reeder SB,Smith MR,Hernando D

更新日期：2016-04-01 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：: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

authors： Peters DC,Lederman RJ,Dick AJ,Raman VK,Guttman MA,Derbyshire JA,McVeigh ER

更新日期：2003-02-01 00:00:00

abstract：:Measurements of the volume magnetic susceptibility of solids using the classical Gouy balance approach are hampered by variations in apparent density of the packed powder. In this paper a quantitative NMR measurement of the volume magnetic susceptibility of powdered solids is described and the volume susceptibility of...

journal_title：Magnetic resonance in medicine

authors： Hopkins JA,Wehrli FW

更新日期：1997-04-01 00:00:00

abstract：PURPOSE:Within multiple sclerosis (MS) lesions iron is present in chronically activated microglia. Thus, iron detection with MRI might provide a biomarker for chronic inflammation within lesions. Here, we examine contributions of iron and myelin to magnetic susceptibility of lesions on quantitative susceptibility mappi...

journal_title：Magnetic resonance in medicine

authors： Wisnieff C,Ramanan S,Olesik J,Gauthier S,Wang Y,Pitt D

更新日期：2015-08-01 00:00:00

abstract：:We studied the fluxes of a potassium congener (Rb(+)) in mouse hearts by (87)Rb MRS at 8.4T. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). We initiated Rb(+) efflux by changing the perfusion medium to Rb(+)-free buffer. Spectra were acquire...

journal_title：Magnetic resonance in medicine

authors： Jilkina O,Xiang B,Kuzio B,Rendell J,Kupriyanov VV

更新日期：2005-05-01 00:00:00

abstract：:AFI (actual flip angle imaging) represents an interesting approach to map the B(1) transmit fields by measuring the spatial variations of the effective flip angle. However, the accuracy of the technique relies on the adequate spoiling of transverse magnetization. In the present work configuration theory was employed t...

journal_title：Magnetic resonance in medicine

authors： Nehrke K

更新日期：2009-01-01 00:00:00

abstract：:Accumulation of lipids in atherosclerotic plaques causes progressive narrowing of the arterial lumen, often followed by thrombosis and ischemia. Currently several different methods, most requiring disruption of the plaque, are used to study the physical properties of lipids accumulated in plaques, and lipid compositio...

journal_title：Magnetic resonance in medicine

authors： Guo W,Morrisett JD,Lawrie GM,DeBakey ME,Hamilton JA

更新日期：1998-02-01 00:00:00

abstract：:SENSitivity Encoding (SENSE) greatly enhances the quality of diffusion-weighted echo-planar imaging (EPI) by reducing blurring and off-resonance artifacts. Such improvement would also be desirable for diffusion tensor imaging (DTI), but measures derived from the diffusion tensor can be extremely sensitive to any kind ...

journal_title：Magnetic resonance in medicine

authors： Bammer R,Auer M,Keeling SL,Augustin M,Stables LA,Prokesch RW,Stollberger R,Moseley ME,Fazekas F

更新日期：2002-07-01 00:00:00

abstract：:One-dimensional spectroscopic imaging of (13)C-4-glutamate turnover is performed in the human brain with a 6 cc nominal voxel resolution at 4T. Data were acquired with an indirect detection approach using a short spin echo single quantum (1)H-(13)C heteronuclear editing method and a 7 cm surface coil with quadrature (...

journal_title：Magnetic resonance in medicine

authors： Pan JW,Stein DT,Telang F,Lee JH,Shen J,Brown P,Cline G,Mason GF,Shulman GI,Rothman DL,Hetherington HP

更新日期：2000-11-01 00:00:00

abstract：:In proton magnetic resonance imaging (MRI) metallic substances lead to magnetic field distortions that often result in signal voids in the adjacent anatomic structures. Thus, metallic objects and superparamagnetic iron oxide (SPIO)-labeled cells appear as hypointense artifacts that obscure the underlying anatomy. The ...

journal_title：Magnetic resonance in medicine

authors： Stuber M,Gilson WD,Schär M,Kedziorek DA,Hofmann LV,Shah S,Vonken EJ,Bulte JW,Kraitchman DL

更新日期：2007-11-01 00:00:00

abstract：:The multiexponential behavior of the decay curves obtained in vitro by a Carr-Purcell-Meiboom-Gill (CPMG) sequence from spleens and kidneys of mice is analyzed. The mice were inoculated with the acute lymphocytic P388 leukemic cells and treated with the anticancer drug cis-diamminedichloroplatinum(II), cis-Pt. Kidneys...

journal_title：Magnetic resonance in medicine

authors： François A,Van Gerven L,Atassi G,Eisendrath H,Gielen M,Willem R

更新日期：1988-08-01 00:00:00

abstract：:Double wave vector diffusion weighting uses gradients along two different directions between excitation and acquisition. It has been shown theoretically that for restricted diffusion the signal amplitude in such an experiment can depend on the angle between the two gradient vectors. The highest amplitude is obtained w...

journal_title：Magnetic resonance in medicine

authors： Koch MA,Finsterbusch J

更新日期：2008-07-01 00:00:00

abstract：PURPOSE:Irreversible electroporation (IRE) is a nonthermal tissue ablation technique that represents a promising treatment option for unresectable liver tumors, but the effectively treated zone cannot be reliably predicted. We investigate the potential benefit of transcatheter intra-arterial perfusion (TRIP) -MRI for t...

journal_title：Magnetic resonance in medicine

authors： Figini M,Zhou K,Pan L,Sun C,Wang B,Hu S,Yang J,Shangguan J,Eresen A,Velichko Y,Yaghmai V,Zhang Z

更新日期：2020-07-01 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

authors： Hu Z,Ma X,Truong TK,Song AW,Guo H

更新日期：2017-07-01 00:00:00

abstract：PURPOSE:To develop and validate a regularization approach of optimizing B1 insensitivity of the quantitative magnetization transfer (qMT) pool-size ratio (F). METHODS:An expression describing the impact of B1 inaccuracies on qMT fitting parameters was derived using a sensitivity analysis. To simultaneously optimize fo...

journal_title：Magnetic resonance in medicine

authors： Boudreau M,Pike GB

更新日期：2018-12-01 00:00:00

abstract：:A 3D sequence for dynamic susceptibility imaging is proposed which combines echo-shifting principles (such as PRESTO), sensitivity encoding (SENSE), and partial-Fourier acquisition. The method uses a moderate SENSE factor of 2 and takes advantage of an alternating partial k-space acquisition in the "slow" phase encode...

journal_title：Magnetic resonance in medicine

authors： Klarhöfer M,Dilharreguy B,van Gelderen P,Moonen CT

更新日期：2003-10-01 00:00:00