Proton exchange rates from amino acid side chains--implications for image contrast.

abstract：:Two different types of (co-registered) images of the same slice of tissue will generally have different spatial resolutions. The judicious pixel-by-pixel combination of their data can be accomplished to yield a single image exhibiting properties of both. Here, axial (18)FDG PET and (1)H(2)O MR images of the human brai...

journal_title：Magnetic resonance in medicine

authors： Sammi MK,Felder CA,Fowler JS,Lee JH,Levy AV,Li X,Logan J,Pályka I,Rooney WD,Volkow ND,Wang GJ,Springer CS Jr

更新日期：1999-08-01 00:00:00

abstract：PURPOSE:The aim of this study was to compare prospective head motion correction and motion tracking abilities of two tracking systems: Active NMR field probes and a Moiré phase tracking camera system using an optical marker. METHODS:Both tracking systems were used simultaneously on human subjects. The prospective head...

journal_title：Magnetic resonance in medicine

authors： Eschelbach M,Aghaeifar A,Bause J,Handwerker J,Anders J,Engel EM,Thielscher A,Scheffler K

更新日期：2019-01-01 00:00:00

abstract：:Fe(III)meso-tetra(4-sulfonatophenyl)porphine (Fe-TPPS4) has been investigated as a potential pH-sensitive nuclear magnetic resonance (NMR) proton image contrast agent. Relaxation rates (1/T1 and 1/T2) of water protons were measured as a function of pH and concentration of Fe-TPPS4 in phosphate-buffered isotonic saline...

journal_title：Magnetic resonance in medicine

authors： Helpern JA,Curtis JC,Hearshen D,Smith MB,Welch KM

更新日期：1987-09-01 00:00:00

abstract：:Strong, extensive magnetic fringe fields are a significant problem with magnetic resonance imaging magnets. This is particularly acute with 4-T, whole-body research magnets. To date this problem has been addressed by restricting an extensive zone around the unshielded magnet or by placing external unsaturated iron shi...

journal_title：Magnetic resonance in medicine

authors： Huson FR,Bryan RN,MacKay WW,Herrick RC,Colvin J,Ford JJ,Pissanetzky S,Plishker GA,Rocha R,Schmidt W

更新日期：1993-01-01 00:00:00

abstract：PURPOSE:MRI-guided thermal ablations require reliable monitoring methods to ensure complete destruction of the diseased tissue while avoiding damage to the surrounding healthy tissue. Based on the fact that thermal ablations result in substantial changes in biomechanical properties, interventional MR elastography (MRE)...

journal_title：Magnetic resonance in medicine

authors： Corbin N,Vappou J,Breton E,Boehler Q,Barbé L,Renaud P,de Mathelin M

更新日期：2016-03-01 00:00:00

abstract：:Diffusion tensor imaging enables in vivo investigation of tissue cytoarchitecture through parameter contrasts sensitive to water diffusion barriers at the micrometer level. Parameters are derived through an estimation process that is susceptible to noise and artifacts. Estimated parameters (e.g., fractional anisotropy...

journal_title：Magnetic resonance in medicine

authors： Lauzon CB,Crainiceanu C,Caffo BC,Landman BA

更新日期：2013-03-01 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：:A new ultrafast MR imaging method is proposed and tested, which enables whole-brain fMRI with a true temporal resolution of 1 sec. The method combines a 3D PRESTO pulse sequence with the concept of sensitivity-encoding with multiple receiver coils (SENSE). The so-called PRESTO-SENSE technique is demonstrated on a set ...

journal_title：Magnetic resonance in medicine

authors： Golay X,Pruessmann KP,Weiger M,Crelier GR,Folkers PJ,Kollias SS,Boesiger P

更新日期：2000-06-01 00:00:00

abstract：:Patient motion and image distortion induced by eddy currents cause artifacts in maps of diffusion parameters computed from diffusion-weighted (DW) images. A novel and comprehensive approach to correct for spatial misalignment of DW imaging (DWI) volumes acquired with different strengths and orientations of the diffusi...

journal_title：Magnetic resonance in medicine

authors： Rohde GK,Barnett AS,Basser PJ,Marenco S,Pierpaoli C

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:In this study, an iterative k-t principal component analysis (PCA) algorithm with nonrigid frame-to-frame motion correction is proposed for dynamic contrast-enhanced three-dimensional perfusion imaging. METHODS:An iterative k-t PCA algorithm was implemented with regularization using training data corrected for...

journal_title：Magnetic resonance in medicine

authors： Schmidt JF,Wissmann L,Manka R,Kozerke S

更新日期：2014-07-01 00:00:00

abstract：:A new decoupling sequence, PBAR, is described for broadband heteronuclear decoupling in vivo in humans at 1.5T. The sequence uses non-adiabatic, frequency- and amplitude-modulated inversion pulses designed to minimize decoupling sidebands at low applied gammaB(2) RF field levels and to cover only the narrow range of r...

journal_title：Magnetic resonance in medicine

authors： Barker PB,Golay X,Artemov D,Ouwerkerk R,Smith MA,Shaka AJ

更新日期：2001-02-01 00:00:00

abstract：PURPOSE:To develop and validate a method for acquiring helium-3 ((3) He) and proton ((1) H) three-dimensional (3D) image sets of the human lung with isotropic spatial resolution within a 10-s breath-hold by using compressed sensing (CS) acceleration, and to assess the fidelity of undersampled images compared with fully...

journal_title：Magnetic resonance in medicine

authors： Qing K,Altes TA,Tustison NJ,Feng X,Chen X,Mata JF,Miller GW,de Lange EE,Tobias WA,Cates GD Jr,Brookeman JR,Mugler JP 3rd

更新日期：2015-10-01 00:00:00

abstract：:The MMQ cell line is a unique prolactin-secreting rat pituitary cell line. MMQ cells entrapped in agarose gel threads are metabolically active, as determined by the uptake and phosphorylation of creatine and the maintenance of high energy phosphates for over 15 h. Forskolin activates the catalytic subunit of adenylyl ...

journal_title：Magnetic resonance in medicine

authors： Goger MJ,Login IS,Fernandez EJ,Grisham CM

更新日期：1994-11-01 00:00:00

abstract：:This study presents the detection of [2-(13)C]glucose metabolism in the carboxylic/amide region in the human brain, and demonstrates that the cerebral metabolism of [2-(13)C]glucose can be studied in human subjects in the presence of severe hardware constraints of widely available 3 T clinical scanners and with low-po...

journal_title：Magnetic resonance in medicine

authors： Li S,Zhang Y,Wang S,Yang J,Ferraris Araneta M,Farris A,Johnson C,Fox S,Innis R,Shen J

更新日期：2009-09-01 00:00:00

abstract：:Phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMR) was used to assess the temporal changes of high-energy phosphate metabolites in the region of acute myocardial ischemia of open-chest cats. Eight anesthetized cats were studied following ligation of the left anterior descending coronary artery. Creatine p...

journal_title：Magnetic resonance in medicine

authors： Stein PD,Goldstein S,Sabbah HN,Liu ZQ,Helpern JA,Ewing JR,Lakier JB,Chopp M,LaPenna WF,Welch KM

更新日期：1986-04-01 00:00:00

abstract：:Imaging of stable paramagnetic spin probes in phantom objects and in vivo was evaluated using a RF time domain EPR spectrometer/imager operating at 300 MHz. Projections were collected using static magnetic field gradients and images were reconstructed using filtered back-projection techniques. Results from phantom obj...

journal_title：Magnetic resonance in medicine

authors： Afeworki M,van Dam GM,Devasahayam N,Murugesan R,Cook J,Coffin D,Larsen JH,Mitchell JB,Subramanian S,Krishna MC

更新日期：2000-03-01 00:00:00

abstract：:Time-dependent changes of T1 in the rotating frame (T1rho), diffusion, T2, and magnetization transfer contrast on cardiac arrest-induced global ischemia in rat were investigated. T1rho, as acquired with spin lock amplitudes >0.6 G, started to increase 10-20 sec after cardiac arrest followed by an increase within 3-4 m...

journal_title：Magnetic resonance in medicine

authors： Kettunen MI,Gröhn OH,Penttonen M,Kauppinen RA

更新日期：2001-09-01 00:00:00

abstract：:Half k-space gradient-recalled echo-planar imaging (GR-EPI) is discussed in detail. T2* decay during full k-space GR-EPI gives rise to unequal weighting of the lines of k-space, loss of signal intensity at the center of k-space, and a point-spread function that limits resolution. In addition, the long readout time for...

journal_title：Magnetic resonance in medicine

authors： Jesmanowicz A,Bandettini PA,Hyde JS

更新日期：1998-11-01 00:00:00

abstract：:Black blood MRI is an attractive tool for monitoring normal and pathological wall thickening; however, limited spatial resolutions can conspire with complex vascular geometries to distort the appearance of the wall in ways hitherto unclear. To elucidate this, a thin-walled cylinder model was developed to predict the c...

journal_title：Magnetic resonance in medicine

authors： Antiga L,Wasserman BA,Steinman DA

更新日期：2008-11-01 00:00:00

abstract：PURPOSE:To assess the use of image registration for correcting respiratory motion in free breathing lung T1 mapping acquisition in patients with idiopathic pulmonary fibrosis (IPF). THEORY AND METHODS:The method presented used image registration to synthetic images during postprocessing to remove respiratory motion. S...

journal_title：Magnetic resonance in medicine

authors： Saunders LC,Eaden JA,Bianchi SM,Swift AJ,Wild JM

更新日期：2020-12-01 00:00:00

abstract：:Proton T(1rho)-dispersion MRI is demonstrated for indirect, in vivo detection of (17)O in the brain. This technique, which may be readily implemented on any clinical MRI scanner, is applied towards high-resolution, quantitative mapping of cerebral blood flow (CBF) in the rat by monitoring the clearance of (17)O-enrich...

journal_title：Magnetic resonance in medicine

authors： Tailor DR,Roy A,Regatte RR,Charagundla SR,McLaughlin AC,Leigh JS,Reddy R

更新日期：2003-03-01 00:00:00

abstract：:A double-tuned single coil probe for high field metabolic NMR studies has been designed and tested. The resonant coil is a single-turn of copper foil wound on a quartz cylinder. It is fed by a short length of parallel strip line made of the same material; the feeder is also used as a tuning capacitance. Electrical par...

journal_title：Magnetic resonance in medicine

authors： Najim E,Grivet JP

更新日期：1992-02-01 00:00:00

abstract：PURPOSE:To develop a rapid imaging framework for balanced steady-state free precession (bSSFP) that jointly reconstructs undersampled data (by a factor of R) across multiple coils (D) and multiple acquisitions (N). To devise a multi-acquisition coil compression technique for improved computational efficiency. METHODS:...

journal_title：Magnetic resonance in medicine

authors： Biyik E,Ilicak E,Çukur T

更新日期：2018-05-01 00:00:00

abstract：:In echo-planar-based diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI), the evaluation of diffusion parameters such as apparent diffusion coefficients and anisotropy indices is affected by image distortions that arise from residual eddy currents produced by the diffusion-sensitizing gradients. Correc...

journal_title：Magnetic resonance in medicine

authors： Bodammer N,Kaufmann J,Kanowski M,Tempelmann C

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:To improve multichannel compressed sensing (CS) reconstruction for MR proton resonance frequency (PRF) shift thermography, with application to MRI-induced RF heating evaluation and MR guided high intensity focused ultrasound (MRgFUS) temperature monitoring. METHODS:A new compressed sensing reconstruction is pr...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Gore JC,Grissom WA

更新日期：2019-06-01 00:00:00

abstract：:Intrascan subject movement in clinical MR spectroscopic examinations may result in inconsistent water suppression that distorts the metabolite signals, frame-to-frame variations in spectral phase and frequency, and consequent reductions in the signal-to-noise ratio due to destructive averaging. Frame-to-frame phase/fr...

journal_title：Magnetic resonance in medicine

authors： Lin JM,Tsai SY,Liu HS,Chung HW,Mulkern RV,Cheng CM,Yeh TC,Chen NK

更新日期：2009-12-01 00:00:00

abstract：:High-field MRI scanners are, in principle, well suited for mouse studies; however, many high-field magnets employ a vertical design that may influence the physiological state of the rodent. The purpose of this study was to investigate the orthostatic response of cerebral blood flow (CBF) in mice during a prolonged MR ...

journal_title：Magnetic resonance in medicine

authors： Foley LM,Hitchens TK,Kochanek PM,Melick JA,Jackson EK,Ho C

更新日期：2005-10-01 00:00:00

abstract：:Most prostate MRI/MRS examinations are performed with an endorectal coil inflated with air, leading to an air-tissue interface that induces magnetic susceptibility gradients within the gland. Inflation of the coil with a barium sulfate suspension is described and compared to inflation with air or liquid perfluorocarbo...

journal_title：Magnetic resonance in medicine

authors： Rosen Y,Bloch BN,Lenkinski RE,Greenman RL,Marquis RP,Rofsky NM

更新日期：2007-05-01 00:00:00

abstract：:MRS has considerable potential for the measurement of drug pharmacokinetics in vivo. In this study single- and double-resonance (31)P MRS was used to investigate the biodistribution, pharmacokinetics, and metabolism of ifosfamide following administration of 500 mg/kg ifosfamide in guinea pigs. (1)H-decoupling was foun...

journal_title：Magnetic resonance in medicine

authors： Mancini L,Payne GS,Dzik-Jurasz AS,Leach MO

更新日期：2003-08-01 00:00:00

abstract：:Baseline distortion in NMR spectroscopy, caused by the "dead time" between signal excitation and detection, makes quantitative interpretation difficult and is aesthetically displeasing. Here the use of the CLEAN algorithm for deconvolving the effect of signal dead time to produce a distortionless baseline is discussed...

journal_title：Magnetic resonance in medicine

authors： McKinnon GC,Burger C,Boesiger P

更新日期：1990-01-01 00:00:00