Ultra-rapid gradient echo imaging.

abstract：:Spatially resolved spectroscopy (SPARS) is a method for obtaining high-resolution NMR spectra of well-defined volumes of human tissues in situ. This method was combined with the Carr-Purcell-Meiboom-Gill multiple-echo sequence for T2, and with inversion recovery for T1 relaxation measurements. Relaxation times obtaine...

journal_title：Magnetic resonance in medicine

authors： Luyten PR,Anderson CM,den Hollander JA

更新日期：1987-05-01 00:00:00

abstract：PURPOSE:To achieve rapid, high resolution whole-brain gray matter (GM) imaging by developing a novel, single-slab three-dimensional dual-echo fast-spin-echo pulse sequence and GM-selective reconstruction. METHODS:Unlike conventional GM imaging that uses time-consuming double-inversion-recovery preparation, the propose...

journal_title：Magnetic resonance in medicine

authors： Lee H,Kim EY,Sohn CH,Park J

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:To present a time-efficient technique for banding reduction in balanced steady-state free precession (bSSFP) imaging using phase-cycled simultaneous multislice (SMS) acquisition with CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration). THEORY:The proposed technique exploits the ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Shao X,Martin T,Moeller S,Yacoub E,Wang DJ

更新日期：2016-12-01 00:00:00

abstract：:Rapid MR imaging using the stimulated echo acquisition mode (STEAM) technique yields single-shot images without any sensitivity to resonance offset effects. However, the absence of susceptibility-induced signal voids or geometric distortions is at the expense of a somewhat lower signal-to-noise ratio than EPI. As a co...

journal_title：Magnetic resonance in medicine

authors： Block KT,Frahm J

更新日期：2008-04-01 00:00:00

abstract：PURPOSE:Dynamic glucose-enhanced (DGE)-MRI based on chemical exchange-sensitive MRI, that is, glucoCEST and gluco-chemical exchange-sensitive spin-lock (glucoCESL), is intrinsically prone to motion-induced artifacts because the final DGE contrast relies on the difference of images, which were acquired with a time gap o...

journal_title：Magnetic resonance in medicine

authors： Boyd PS,Breitling J,Zimmermann F,Korzowski A,Zaiss M,Schuenke P,Weinfurtner N,Schlemmer HP,Ladd ME,Bachert P,Paech D,Goerke S

更新日期：2020-07-01 00:00:00

abstract：:With standard spectroscopic imaging, high spatial resolution is achieved at the price of a large number of phase-encoding steps, leading to long acquisition times. Fast spatial encoding methods reduce the minimum total acquisition time. In this article, a k-space scanning scheme using a continuous series of growing an...

journal_title：Magnetic resonance in medicine

authors： Hiba B,Faure B,Lamalle L,Décorps M,Ziegler A

更新日期：2003-12-01 00:00:00

abstract：:Gradient-echo EPI, blood oxygenation level-dependent (BOLD) functional MRI (fMRI) using parallel imaging (PI) is demonstrated at 7 Tesla with 16 channels, a fourfold 1D reduction factor (R), and fourfold maximal aliasing. The resultant activation detection in finger-tapping fMRI studies was robust, in full agreement w...

journal_title：Magnetic resonance in medicine

authors： Moeller S,Van de Moortele PF,Goerke U,Adriany G,Ugurbil K

更新日期：2006-07-01 00:00:00

abstract：:For protons diffusing among a system of magnetic particles, the process by which initial phase coherence is lost depends substantially on particle size. In this article, evidence for three dephasing mechanisms is presented: an incremental process at small particle sizes (motional averaging regime), a discrete process ...

journal_title：Magnetic resonance in medicine

authors： de Haan HW

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:Cardiac stimulation (CS) limits to gradient coil switching speed are difficult to measure in humans; instead, current regulatory guidelines (IEC 60601-2-33) are based on animal experiments and electric field-to-dB/dt conversion factors computed for a simple, homogeneous body model. We propose improvement to thi...

journal_title：Magnetic resonance in medicine

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

更新日期：2021-02-01 00:00:00

abstract：PURPOSE:To optimize radiofrequency (RF) pulses for the selective excitation of dissolved phase (129)Xe that take into account the very short T2*, while simultaneously, minimally exciting the much larger gas signal. METHODS:Numerical simulations of Shinnar le-Roux pulses and binomial coefficient composite-element pulse...

journal_title：Magnetic resonance in medicine

authors： Leung G,Norquay G,Schulte RF,Wild JM

更新日期：2015-01-01 00:00:00

abstract：:Chemical shifts were extracted from in vivo 3-dimensional 31P NMR CSI data and pH images were constructed. The images could spatially resolve tissue pH ranging from 5.8 to 7.2 (with uncertainty of 0.11-0.17 pH unit) in an ischemia-reperfusion model of diabetic rat calf muscles. ...

journal_title：Magnetic resonance in medicine

authors： Morikawa S,Inubushi T,Kito K,Kido C

更新日期：1993-02-01 00:00:00

abstract：:Since its inception, functional magnetic resonance imaging (fMRI) has seen rapid progress in the application to neuroscience. Common gradient-recalled acquisition methods are susceptible to static field inhomogeneities, resulting in signal loss at the medial temporal area important for memory function or at the basal ...

journal_title：Magnetic resonance in medicine

authors： Song AW,Mao H,Muthupillai R,Haist F,Dixon WT

更新日期：1999-10-01 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：:A MultiEcho Segmented EPI with z-shimmed BAckground gradient Compensation (MESBAC) pulse sequence is proposed and validated for functional MRI (fMRI) study in regions suffering from severe susceptibility artifacts. This sequence provides an effective tradeoff between spatial and temporal resolution and reduces image d...

journal_title：Magnetic resonance in medicine

authors： Li Z,Wu G,Zhao X,Luo F,Li SJ

更新日期：2002-08-01 00:00:00

abstract：PURPOSE:To develop a fully automated trajectory and gradient waveform design for the non-Cartesian shells acquisition, and to develop a magnetization-prepared (MP) shells acquisition to achieve an efficient three-dimensional acquisition with improved gray-to-white brain matter contrast. METHODS:After reviewing the she...

journal_title：Magnetic resonance in medicine

authors： Shu Y,Tao S,Trzasko JD,Huston J 3rd,Weavers PT,Bernstein MA

更新日期：2018-04-01 00:00:00

abstract：:Hyperpolarized noble gas ((3)He and (129)Xe) apparent diffusion coefficient (ADC) measurements have shown remarkable sensitivity to microstructural (i.e., alveolar) changes in the lung, particularly emphysema. The ADC of hyperpolarized noble gases depends strongly on the diffusion time (Δ), and (3)He ADC has been show...

journal_title：Magnetic resonance in medicine

authors： Boudreau M,Xu X,Santyr GE

更新日期：2013-01-01 00:00:00

abstract：:This paper describes a technique for characterizing the gradient subsystem of a magnetic resonance (MR) system. The technique uses a Fourier-transform analysis to directly measure the k-space trajectory produced by an arbitrary gradient waveform. In addition, the method can be easily extended to multiple dimensions an...

journal_title：Magnetic resonance in medicine

authors： Alley MT,Glover GH,Pelc NJ

更新日期：1998-04-01 00:00:00

abstract：PURPOSE:To enable highly accelerated distortion-free MRI near metal by separating on- and off-resonance to exploit the redundancy of slice-phase encoding for the dominant on-resonance component. METHODS:Multispectral MRI techniques resolve off-resonance distortions by a combination of limited excitation bins and addit...

journal_title：Magnetic resonance in medicine

authors： Levine E,Stevens K,Beaulieu C,Hargreaves B

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:The use of electromagnetic (EM) modeling is critical for specific absorption rate (SAR) characterization in parallel transmission MRI. Radiofrequency arrays that include decoupling networks can be difficult to characterize accurately in simulation. A practical method of simplifying modeling is to exclude the de...

journal_title：Magnetic resonance in medicine

authors： Beqiri A,Hand JW,Hajnal JV,Malik SJ

更新日期：2015-11-01 00:00:00

abstract：:Human intervertebral discs were investigated by 1H NMR in vitro. The measured parameters of samples differently located in discs give the "maps" of discs. The spin-lattice relaxation-time maps show similar structure to dry matter and bound water maps, which might mean the future possibility to detect certain disc proc...

journal_title：Magnetic resonance in medicine

authors： Furó I,Bobest M,Pócsik I,Tompa K

更新日期：1986-02-01 00:00:00

abstract：PURPOSE:Measurement of venous oxygenation (Yv) is a critical step toward quantitative assessment of brain oxygen metabolism, a key index in many brain disorders. The present study aims to develop a noninvasive, rapid, and reproducible method to measure Yv in a vessel-specific manner. THEORY:The method, T2-Relaxation-U...

journal_title：Magnetic resonance in medicine

authors： Krishnamurthy LC,Liu P,Ge Y,Lu H

更新日期：2014-03-01 00:00:00

abstract：:The course of pulmonary edema formation after an intratracheal (i.t.) instillation of ovalbumin was followed noninvasively by magnetic resonance imaging (MRI) in actively sensitized Brown Norway (BN) rats. Changes in edema volume assessed by MRI mimicked the results from the analysis of the number and activation of in...

journal_title：Magnetic resonance in medicine

authors： Beckmann N,Tigani B,Ekatodramis D,Borer R,Mazzoni L,Fozard JR

更新日期：2001-01-01 00:00:00

abstract：PURPOSE:To compare the performance of an 8-channel surface coil/clamshell transmitter and 32-channel head array coil/birdcage transmitter for hyperpolarized 13 C brain metabolic imaging. METHODS:To determine the field homogeneity of the radiofrequency transmitters, B1 + mapping was performed on an ethylene glycol head...

journal_title：Magnetic resonance in medicine

authors： Autry AW,Gordon JW,Carvajal L,Mareyam A,Chen HY,Park I,Mammoli D,Vareth M,Chang SM,Wald LL,Xu D,Vigneron DB,Nelson SJ,Li Y

更新日期：2019-08-01 00:00:00

abstract：PURPOSE:To introduce and evaluate an image registration technique for robust quantification of CEST acquisitions corrupted by motion. METHODS:The proposed iterative algorithm exploits a low-rank approximation of the z-spectrum (LRAZ), to gradually separate the contrast variation due to saturation at different off-reso...

journal_title：Magnetic resonance in medicine

authors： Wech T,Köstler H

更新日期：2018-11-01 00:00:00

abstract：:Changes in molecular expression or apoptotic behavior, induced by malignant transformation or anticancer treatment, are frequently reflected in cellular metabolism and oxygen consumption. A technique to monitor oxygen consumption, cell physiology, and metabolism noninvasively would provide a better understanding of in...

journal_title：Magnetic resonance in medicine

authors： Pilatus U,Aboagye E,Artemov D,Mori N,Ackerstaff E,Bhujwalla ZM

更新日期：2001-05-01 00:00:00

abstract：:T(2) quantification may augment diagnostic T(2)-weighted imaging; to improve cancer detection via auto-segmentation of multi-parametric acquisitions and to potentiate longitudinal studies of prostate cancer. However, robust quantitative techniques are not generally accessible or refined for clinical translation. This ...

journal_title：Magnetic resonance in medicine

authors： Foltz WD,Chopra S,Chung P,Bayley A,Catton C,Jaffray D,Wright GA,Haider MA,Ménard C

更新日期：2010-10-01 00:00:00

abstract：PURPOSE:To perform quantitative susceptibility mapping (QSM) in negligible acquisition time and apply it to measuring iron-rich subcortical gray matter. METHODS:Whole brain QSM was performed using single-shot gradient echo-planar imaging (EPI) in under 7 seconds on a standard 1.5 T system for imaging brain iron in sub...

journal_title：Magnetic resonance in medicine

authors： Sun H,Wilman AH

更新日期：2015-05-01 00:00:00

abstract：PURPOSE:The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. THEORY AND METHODS:A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of ...

journal_title：Magnetic resonance in medicine

authors： Romu T,Dahlström N,Leinhard OD,Borga M

更新日期：2017-09-01 00:00:00

abstract：:The previously observed improvement in spectral resolution of tissue proton NMR with high-resolution magic angle spinning (HRMAS) was speculated to be due largely to freeze-thawing artifacts resulting from tissue storage. In this study, 12 human prostate samples were analyzed on a 14.1T spectrometer at 3 degrees C, wi...

journal_title：Magnetic resonance in medicine

authors： Wu CL,Taylor JL,He W,Zepeda AG,Halpern EF,Bielecki A,Gonzalez RG,Cheng LL

更新日期：2003-12-01 00:00:00

abstract：:Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory an...

journal_title：Magnetic resonance in medicine

authors： Aerts HJ,van Riel NA,Backes WH

更新日期：2008-05-01 00:00:00