3D-multi-spectral T2 mapping near metal implants.

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

abstract：:Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...

journal_title：Magnetic resonance in medicine

authors： Weisskoff RM

更新日期：1996-10-01 00:00:00

abstract：:To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were...

journal_title：Magnetic resonance in medicine

authors： Rose SE,Hatzigeorgiou X,Strudwick MW,Durbridge G,Davies PS,Colditz PB

更新日期：2008-10-01 00:00:00

abstract：:A new approach to autocalibrating, coil-by-coil parallel imaging reconstruction, is presented. It is a generalized reconstruction framework based on self-consistency. The reconstruction problem is formulated as an optimization that yields the most consistent solution with the calibration and acquisition data. The appr...

journal_title：Magnetic resonance in medicine

authors： Lustig M,Pauly JM

更新日期：2010-08-01 00:00:00

abstract：:The feasibility of reconstructing three-dimensional (3D) MRI data sets from limited-view projections is investigated in phantom and in vivo animal studies to improve the temporal resolution of magnetic resonance angiography without sacrificing spatial resolution. Thirty-two pairs of orthogonal biplane projections are ...

journal_title：Magnetic resonance in medicine

authors： Huang Y,Gurr D,Wright GA

更新日期：2006-01-01 00:00:00

abstract：:A novel and automated technique is described for removing fMRI image artifacts resulting from motion outside of the imaging field of view. The technique is based on the Stockwell transform (ST), a mathematical operation that provides the frequency content at each time point within a time-varying signal. Using this tec...

journal_title：Magnetic resonance in medicine

authors： Goodyear BG,Zhu H,Brown RA,Mitchell JR

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:To demonstrate feasibility of transceive phase mapping with the PLANET method and its application for conductivity reconstruction in the brain. METHODS:Accuracy and precision of transceive phase (ϕ± ) estimation with PLANET, an ellipse fitting approach to phase-cycled balanced steady state free precession (bSS...

journal_title：Magnetic resonance in medicine

authors： Gavazzi S,Shcherbakova Y,Bartels LW,Stalpers LJA,Lagendijk JJW,Crezee H,van den Berg CAT,van Lier ALHMW

更新日期：2020-02-01 00:00:00

abstract：:The fate of the 13C label arising from [U-13C]succinate in rabbit renal proximal convoluted tubular (PCT) cells, incubated with [U-13C]succinate, was investigated by 13C NMR spectroscopy of the perchloric acid extracts of the cell pellets. The 13C label of [U-13C]succinate was predominantly metabolized into glutamate,...

journal_title：Magnetic resonance in medicine

authors： Jans AW,Willem R

更新日期：1990-04-01 00:00:00

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

authors： Korzowski A,Bachert P

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. METHODS:Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were ima...

journal_title：Magnetic resonance in medicine

authors： Fyrdahl A,Vargas Paris R,Nyrén S,Holst K,Ugander M,Lindholm P,Sigfridsson A

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:To characterize pseudo-continuous arterial spin labeling (pCASL) through simulations of spin inversion and to discuss suitable parameter settings for measuring cerebral perfusion. METHODS:Simulations of arterial spin inversion in pCASL were performed based on the Bloch equation. Both the labeling and the contr...

journal_title：Magnetic resonance in medicine

authors： Lorenz K,Mildner T,Schlumm T,Möller HE

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:A new T1 mapping method is proposed that is accurate, rapid, and robust to motion. Considering these features, the method is dubbed "T-One with Enhanced Robustness and Speed (TOWERS)." METHODS:TOWERS is composed of inversion recovery (IR) and saturation recovery (SR) acquisitions. In the IR acquisitions, a sli...

journal_title：Magnetic resonance in medicine

authors： Eldeniz C,Finsterbusch J,Lin W,An H

更新日期：2016-07-01 00:00:00

abstract：:Measuring T(2) at 7.0 T is not trivial due to RF inhomogeneity effects, however, gradient echo sampling of a spin echo is insensitive to RF pulse errors, does not suffer from significant distortions, and allows T'(2) and T(2) to be estimated simultaneously. Gradient echo sampling of a spin echo results are relatively ...

journal_title：Magnetic resonance in medicine

authors： Cox EF,Gowland PA

更新日期：2010-11-01 00:00:00

abstract：:The role of relative cerebral blood volume (rCBV) in the early response of blood oxygenation level-dependent (BOLD) signal following sensory stimulation was assessed. Magnetic resonance imaging (MRI) measurements of rCBV and BOLD signal as a function of time (t) were compared with relative cerebral blood flow (rCBF) o...

journal_title：Magnetic resonance in medicine

authors： Marota JJ,Ayata C,Moskowitz MA,Weisskoff RM,Rosen BR,Mandeville JB

更新日期：1999-02-01 00:00:00

abstract：:The water proton resonance frequency (PRF) is temperature dependent and can thus be used for magnetic resonance (MR) thermometry. Since lipid proton resonance frequencies do not depend on temperature, fat suppression is essential for PRF-based temperature mapping. The efficacy of echo-shifted (TE > TR) gradient-echo i...

journal_title：Magnetic resonance in medicine

authors： de Zwart JA,Vimeux FC,Delalande C,Canioni P,Moonen CT

更新日期：1999-07-01 00:00:00

abstract：:The objective of this study is to evaluate the effect of MR image resolution on trabecular bone parameters and to determine the acceptable resolution that can be accurately analyzed to assess structural parameters. Ten distal femoral condyle specimens of 1 × 1 × 1 cm(3) were scanned with a 4.7-T Bruker BioSpec MRI sca...

journal_title：Magnetic resonance in medicine

authors： Kim N,Lee JG,Song Y,Kim HJ,S Yeom J,Cho G

更新日期：2012-01-01 00:00:00

abstract：PURPOSE:To develop a framework for respiratory motion-corrected 3D whole-heart water/fat coronary MR angiography (CMRA) at 3T with reduced and predictable scan time. METHODS:A 3D dual-echo acquisition and respiratory motion-corrected reconstruction framework for water/fat CMRA imaging was developed. The acquisition se...

journal_title：Magnetic resonance in medicine

authors： Munoz C,Cruz G,Neji R,Botnar RM,Prieto C

更新日期：2019-08-01 00:00:00

abstract：:The effects of macroscopic background field gradients upon 2D gradient echo images of inhaled (3)He in the human lung were investigated at 1.5 T. Effective compensation of in-slice signal loss in (3)He gradient echo images was then demonstrated using a multiple acquisition interleaved single gradient echo sequence. Th...

journal_title：Magnetic resonance in medicine

authors： Wild JM,Fichele S,Woodhouse N,Paley MN,Swift A,Kasuboski L,van Beek EJ

更新日期：2003-08-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 00:00:00

abstract：:Variations in T(1ρ) with locking-field strength (T(1ρ) dispersion) may be used to estimate proton exchange rates. We developed a novel approach utilizing the second derivative of the dispersion curve to measure exchange in a model system of cross-linked polyacrylamide gels. These gels were varied in relative compositi...

journal_title：Magnetic resonance in medicine

authors： Cobb JG,Xie J,Gore JC

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:Spatio-temporal encoding (SPEN) experiments can deliver single-scan MR images without folding complications and with robustness to chemical shift and susceptibility artifacts. Further resolution improvements are shown to arise by relying on multiple receivers, to interpolate the sampled data along the low-bandw...

journal_title：Magnetic resonance in medicine

authors： Liberman G,Solomon E,Lustig M,Frydman L

更新日期：2018-02-01 00:00:00

abstract：:T1 is often ill-determined. This means that an Ernst angle excitation often cannot be precisely defined for the simple pulse and acquire experiment. Here, published 31P T1 values of metabolites in human muscle, liver, heart, and brain are archived, some new data on heart and brain added, and overall confidence interva...

journal_title：Magnetic resonance in medicine

authors： Bottomley PA,Ouwerkerk R

更新日期：1994-07-01 00:00:00

abstract：:A new parallel imaging technique was implemented which can result in reduced image acquisition times in MRI. MR data is acquired in parallel using an array of receiver coils and then reconstructed simultaneously with multiple processors. The method requires the initial estimation of the 2D sensitivity profile of each ...

journal_title：Magnetic resonance in medicine

authors： Kyriakos WE,Panych LP,Kacher DF,Westin CF,Bao SM,Mulkern RV,Jolesz FA

更新日期：2000-08-01 00:00:00

abstract：:The focal underdetermined system solver (FOCUSS) was originally designed to obtain sparse solutions by successively solving quadratic optimization problems. This article adapts FOCUSS for a projection reconstruction MR imaging problem to obtain high resolution reconstructions from angular under-sampled radial k-space ...

journal_title：Magnetic resonance in medicine

authors： Ye JC,Tak S,Han Y,Park HW

更新日期：2007-04-01 00:00:00

abstract：:Functional magnetic resonance imaging (fMRI) has become the most widely used modality for visualizing regional brain activation in response to sensorimotor or cognitive tasks. While the majority of fMRI studies have used blood oxygenation level-dependent (BOLD) contrast as a marker for neural activation, baseline drif...

journal_title：Magnetic resonance in medicine

authors： Wang J,Aguirre GK,Kimberg DY,Roc AC,Li L,Detre JA

更新日期：2003-05-01 00:00:00

abstract：:This communication describes the design and application of a receiver coil operating at liquid nitrogen temperature and intended as a surface coil in a whole-body imager. Its particular application is seen as the external receiver for parasitic internal or implanted detectors. ...

journal_title：Magnetic resonance in medicine

authors： Hall AS,Barnard B,McArthur P,Gilderdale DJ,Young IR,Bydder GM

更新日期：1988-06-01 00:00:00

abstract：PURPOSE:This assesses the potential of measuring lactate in the human brain using three non-editing MRS methods at 7T and compares the accuracy and precision of the methods. METHODS:1 H MRS data were measured in the right dorsolateral prefrontal cortex using a semi-adiabatic spin-echo full-intensity acquired localized...

journal_title：Magnetic resonance in medicine

authors： Dehghani M,Do KQ,Magistretti P,Xin L

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:Magnetically labeled cells and tissue iron deposits provide qualitative means to detect and monitor cardiovascular and cerebrovascular diseases with magnetic resonance imaging. However, to quantitatively examine the extent of pathological micromorphological changes, detailed knowledge about microstructural para...

journal_title：Magnetic resonance in medicine

authors： Kurz FT,Kampf T,Heiland S,Bendszus M,Schlemmer HP,Ziener CH

更新日期：2014-05-01 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

authors： Gudbjartsson H,Patz S

更新日期：1995-12-01 00:00:00

abstract：:Surgical specimens from 22 patients with infiltrating ductal carcinoma of the breast were analyzed by high-resolution 1H NMR spectroscopy at 80 and 300 MHz. Results were compared with those obtained from 9 benign (proliferative dysplasia without atypia) breast samples. NMR spectra at 80 MHz showed well-resolved water ...

journal_title：Magnetic resonance in medicine

authors： Bradamante S,Barchiesi E,Pilotti S,Borasi G

更新日期：1988-12-01 00:00:00