Proton NMR spectroscopy of solvent-saturable resonances: a new approach to study pH effects in situ.


:It is shown that the effect of pH changes can be measured in proton NMR spectra through the pH sensitivity of the signal intensities of metabolite protons exchanging with water. To observe this phenomenon, pulse sequences must be used that can sensitively observe these exchangeable protons under physiological conditions, which is achieved by avoiding magnetization transfer signal losses due to water saturation for solvent suppression purposes. These methods provide an order-of-magnitude enhancement of many signals between 5 and 10 ppm, containing both N-bound protons as well as aromatic C-H protons coupled to them, the intensity of which is influenced by exchange-relayed saturation. As a first application, the effects of pH change on these resonances are studied ex vivo (perfused cells) and in vivo (cat brain).


Magn Reson Med


Mori S,Eleff SM,Pilatus U,Mori N,van Zijl PC




Has Abstract


1998-07-01 00:00:00












  • More accurate estimation of diffusion tensor parameters using diffusion Kurtosis imaging.

    abstract::With diffusion tensor imaging, the diffusion of water molecules through brain structures is quantified by parameters, which are estimated assuming monoexponential diffusion-weighted signal attenuation. The estimated diffusion parameters, however, depend on the diffusion weighting strength, the b-value, which hampers t...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Veraart J,Poot DH,Van Hecke W,Blockx I,Van der Linden A,Verhoye M,Sijbers J

    更新日期:2011-01-01 00:00:00

  • Artifacts and signal loss due to flow in the presence of B(o) inhomogeneity.

    abstract::An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Drangova M,Pelc NJ

    更新日期:1996-01-01 00:00:00

  • Multifrequency selective rf pulses for multislice MR imaging.

    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


    authors: Müller S

    更新日期:1988-03-01 00:00:00

  • Assessment and correction of macroscopic field variations in 2D spoiled gradient-echo sequences.

    abstract:PURPOSE:To model and correct the dephasing effects in the gradient-echo signal for arbitrary RF excitation pulses with large flip angles in the presence of macroscopic field variations. METHODS:The dephasing of the spoiled 2D gradient-echo signal was modeled using a numerical solution of the Bloch equations to calcula...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Soellradl M,Lesch A,Strasser J,Pirpamer L,Stollberger R,Ropele S,Langkammer C

    更新日期:2020-08-01 00:00:00

  • Quantitative fat and R2* mapping in vivo to measure lipid-rich necrotic core and intraplaque hemorrhage in carotid atherosclerosis.

    abstract:PURPOSE:The aim of this work was to quantify the extent of lipid-rich necrotic core (LRNC) and intraplaque hemorrhage (IPH) in atherosclerotic plaques. METHODS:Patients scheduled for carotid endarterectomy underwent four-point Dixon and T1-weighted magnetic resonance imaging (MRI) at 3 Tesla. Fat and R2* maps were gen...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Koppal S,Warntjes M,Swann J,Dyverfeldt P,Kihlberg J,Moreno R,Magee D,Roberts N,Zachrisson H,Forssell C,Länne T,Treanor D,de Muinck ED

    更新日期:2017-07-01 00:00:00

  • Radiofrequency energy deposition and radiofrequency power requirements in parallel transmission with increasing distance from the coil to the sample.

    abstract:PURPOSE:We investigated global specific absorption rate (SAR) and radiofrequency (RF) power requirements in parallel transmission as the distance between the transmit coils and the sample was increased. METHODS:We calculated ultimate intrinsic SAR (UISAR), which depends on object geometry and electrical properties but...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Deniz CM,Vaidya MV,Sodickson DK,Lattanzi R

    更新日期:2016-01-01 00:00:00

  • Improved selectivity of double quantum coherence filtering for the detection of glutathione in the human brain in vivo.

    abstract::An improved double quantum coherence (DQC) filter for the selective in vivo detection of glutathione (GSH) in the human brain at 1.5 Tesla is presented. The goal was to minimize contamination of the DQC-filtered GSH signal at 2.9 ppm with contributions arising from GABA. The modification consists of tailoring the freq...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Trabesinger AH,Boesiger P

    更新日期:2001-04-01 00:00:00

  • Composite MRA: statistical approach to generate an MR angiogram from multiple contrasts.

    abstract:PURPOSE:To develop a method to use information from multiple MRI contrasts to produce a composite angiogram with reduced sequence-specific artifacts and improved vessel depiction. METHODS:Bayesian posterior vessel probability was determined as a function of black blood (BB), contrast enhanced angiography (CE-MRA), and...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Kim D,Edjlali M,Turski P,Johnson KM

    更新日期:2020-03-01 00:00:00

  • Transcatheter intra-arterial perfusion (TRIP)-MRI biomarkers help detect immediate response to irreversible electroporation of rabbit VX2 liver tumor.

    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

    pub_type: 杂志文章


    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

  • 3D single-shot VASO using a Maxwell gradient compensated GRASE sequence.

    abstract::The vascular space occupancy (VASO) method was recently proposed as a functional MRI (fMRI) method that is capable of detecting activation-related changes in blood volume (CBV), without the need for a blood-pool contrast agent. In the present work we introduce a new whole-brain VASO technique that is based on a parall...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Poser BA,Norris DG

    更新日期:2009-07-01 00:00:00

  • Measurement of perfusion and permeability from dynamic contrast-enhanced MRI in normal and pathological vertebral bone marrow.

    abstract::Dynamic contrast-enhanced MRI data in vertebral bone marrow (vBM) are currently analyzed with descriptive indices. The purpose of this study was to develop and evaluate a quantitative approach, considering the tissue composition of vBM. Therefore, a measurement of the water fraction, f(wat), and the precontrast relaxa...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Biffar A,Sourbron S,Schmidt G,Ingrisch M,Dietrich O,Reiser MF,Baur-Melnyk A

    更新日期:2010-07-01 00:00:00

  • Improved estimation of velocity and flow rate using regularized three-point phase-contrast velocimetry.

    abstract::We improved the three-point phase-contrast method by regularization of MR velocity data after acquisition of a low velocity-to-noise ratio (VNR) velocity image and a high VNR aliased velocity image. The phase unwrapping algorithm is based on the assumed correlation of the velocity of adjacent flow voxels on the low VN...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Herment A,Mousseaux E,Jolivet O,DeCesare A,Frouin F,Todd-Pokropek A,Bittoun J

    更新日期:2000-07-01 00:00:00

  • Rapid acquisition of helium-3 and proton three-dimensional image sets of the human lung in a single breath-hold using compressed sensing.

    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

    pub_type: 杂志文章


    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

  • In vivo GABA editing using a novel doubly selective multiple quantum filter.

    abstract::A novel multiple quantum filtering method is proposed that uses a doubly selective pulse termed Delays Alternating with Nutations for Tailored Excitation (DANTE) for multiple quantum preparation. This method selectively prepares GABA-3 and GABA-4 into a multiple quantum state and suppresses all other resonances at 3.0...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Shen J,Rothman DL,Brown P

    更新日期:2002-03-01 00:00:00

  • One-minute whole-brain magnetization transfer ratio imaging with intrinsic B1-correction.

    abstract:PURPOSE:Magnetization transfer ratio (MTR) histograms are used widely for the assessment of diffuse pathological changes in the brain. For broad clinical application, MTR scans should not only be fast, but confounding factors should also be minimized for high reproducibility. To this end, a 1-minute whole-brain spiral ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Afshari R,Santini F,Heule R,Meyer CH,Pfeuffer J,Bieri O

    更新日期:2020-12-08 00:00:00

  • Multidimensionally encoded magnetic resonance imaging.

    abstract::Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstruct...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Lin FH

    更新日期:2013-07-01 00:00:00

  • Respiration based steering for high intensity focused ultrasound liver ablation.

    abstract:PURPOSE:Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS:Mapping a signa...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Holbrook AB,Ghanouni P,Santos JM,Dumoulin C,Medan Y,Pauly KB

    更新日期:2014-02-01 00:00:00

  • High resolution quantitative relaxation and diffusion MRI of three different experimental brain tumors in rat.

    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

    pub_type: 杂志文章


    authors: Eis M,Els T,Hoehn-Berlage M

    更新日期:1995-12-01 00:00:00

  • Compensation of breathing motion artifacts for MRI with continuously moving table.

    abstract::Breathing motion is one of the main sources of artifacts in MRI acquisitions that can severely impair diagnosis. In MRI with continuously moving table, the application of common motion compensation approaches such as breath holding or the synchronization of the measurement with the breathing motion can be problematic....

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Honal M,Leupold J,Huff S,Baumann T,Ludwig U

    更新日期:2010-03-01 00:00:00

  • Accelerated 3D T2 mapping with dictionary-based matching for prostate imaging.

    abstract:PURPOSE:To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. METHODS:3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisit...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Roccia E,Vidya Shankar R,Neji R,Cruz G,Munoz C,Botnar R,Goh V,Prieto C,Dregely I

    更新日期:2019-03-01 00:00:00

  • Imaging oxygen tension in liver and spleen by 19F NMR.

    abstract::19F NMR imaging of the perfluorocarbon emulsion Fluosol has been used to study regional variations in oxygen tension in rat liver and spleen. We have used the linear dependence of spin lattice relaxation rate (1/T1) on the partial oxygen pressure (pO2) of Fluosol to determine the oxygen tension in the reticuloendothel...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Holland SK,Kennan RP,Schaub MM,D'Angelo MJ,Gore JC

    更新日期:1993-04-01 00:00:00

  • The impact of the relaxivity definition on the quantitative measurement of glycosaminoglycans in cartilage by the MRI dGEMRIC method.

    abstract::The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Zheng S,Xia Y

    更新日期:2010-01-01 00:00:00

  • Evidence for a contribution of paramagnetic ions to water proton spin-lattice relaxation in normal and malignant mouse tissues.

    abstract::Paramagnetic ions complexed to proteins may lose, retain, or enhance solvent paramagnetic relaxation (SPR) relative to free solution. We measured T1 and T2 of three mouse cancers, their normal counterparts, and six additional tissues. Long T1 of cancers was not caused by necrosis or by different contents of water, fat...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Negendank W,Corbett T,Crowley M,Kellogg C

    更新日期:1991-04-01 00:00:00

  • High-resolution 3D proton spectroscopic imaging of the human brain at 3 T: SNR issues and application for anatomy-matched voxel sizes.

    abstract::In a systematic study on the interdependence of linewidth, signal-to-noise ratio (SNR), and spatial resolution in 3D proton spectroscopic imaging ((1)H-SI) at 3 T, we demonstrate reduced linewidths with increased spatial resolution due to reduced magnetic inhomogeneity within the brain. High-precision quantitative dat...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Gruber S,Mlynárik V,Moser E

    更新日期:2003-02-01 00:00:00

  • Variable flip angle 3D-GRASE for high resolution fMRI at 7 tesla.

    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

    pub_type: 杂志文章


    authors: Kemper VG,De Martino F,Yacoub E,Goebel R

    更新日期:2016-09-01 00:00:00

  • Lactate isotopomer analysis by 1H NMR spectroscopy: consideration of long-range nuclear spin-spin interactions.

    abstract::Lactate is a key metabolite and its rates of cellular uptake and release, its production rates from glucose and glycogen, and its interconversion rate with pyruvate are important determinants of cellular energy production. If lactate precursors such as pyruvate and glucose are labeled appropriately with (13)C, (1)H NM...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Lloyd SG,Zeng H,Wang P,Chatham JC

    更新日期:2004-06-01 00:00:00

  • Cardiac gating using scattering of an 8-channel parallel transmit coil at 7T.

    abstract:PURPOSE:To establish a cardiac signal from scattering matrix or scattering coefficient measurements made on a 7T 8-channel parallel transmit (pTx) system, and to evaluate its use for cardiac gating. METHODS:Measurements of the scattering matrix and scattering coefficients were acquired using a monitoring pulse sequenc...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Jaeschke SHF,Robson MD,Hess AT

    更新日期:2018-08-01 00:00:00

  • Analysis and correction of motion artifacts in diffusion weighted imaging.

    abstract::For diffusion-weighted magnetic resonance imaging and under circumstances where patient movement can be modeled as rigid body motion, it is shown both theoretically and experimentally that translations and rotations produce phase errors which are zero- and first-order, respectively, in position. While a navigator echo...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Anderson AW,Gore JC

    更新日期:1994-09-01 00:00:00

  • High-resolution 31 P echo-planar spectroscopic imaging in vivo at 7T.

    abstract:PURPOSE:Conventional 31 P chemical shift imaging is time-consuming and yields only limited spatial resolution. The purpose of this study was to demonstrate feasibility of 31 P echo-planar spectroscopic imaging (EPSI) in vivo at 7T. METHODS:A 3D 31 P EPSI sequence with trapezoidal-shaped gradient pulses was implemented...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Korzowski A,Bachert P

    更新日期:2018-03-01 00:00:00

  • Cooperative T1 and T2 effects on contrast using a new driven inversion spin-echo (DISE) MRI pulse sequence.

    abstract::A pulse sequence is presented for obtaining a single image with combined T1/T2 weighting. T2 relaxation is made to increase intensity, in cooperation with the effect of T1 relaxation, by providing T2 weighting with a 90 degrees-180 degrees-90 degrees driven inversion pulse triplet in an inversion recovery method. Unli...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Conturo TE,Kessler RM,Beth AH

    更新日期:1990-09-01 00:00:00