Evaluation of wave delivery methodology for brain MRE: Insights from computational simulations.

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：:Fractional anisotropy (FA) and relative anisotropy (RA) are the two most commonly used scalar measures of anisotropy in diffusion tensor (DT) MRI. While a few published studies have shown that FA has superior noise immunity relative to RA, no theoretical basis has been proposed to explain this behavior. In the current...

journal_title：Magnetic resonance in medicine

authors： Hasan KM,Alexander AL,Narayana PA

更新日期：2004-02-01 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：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：:The preovulatory rat follicle reaches a diameter of 1 mm with no internal blood vessels. Nutrient supply to the enclosed oocyte depends solely on passive diffusion across the follicular wall and the follicular fluid. Spin-echo and stimulated-echo NMR microscopy experiments were applied here for studying modulations in...

journal_title：Magnetic resonance in medicine

authors： Tempel C,Schiffenbauer YS,Meir G,Neeman M

更新日期：1995-08-01 00:00:00

abstract：:The chemical shift of water and fat resonances in proton MRI allows separation of water and fat signal from chemical shift encoded data. This work describes an automatic method that produces separate water and fat images as well as quantitative maps of fat signal fraction and T2* from complex multiecho gradient-recall...

journal_title：Magnetic resonance in medicine

authors： Berglund J,Kullberg J

更新日期：2012-06-01 00:00:00

abstract：:Radial MRI sequences are frequently used to obtain images with reduced sensitivity to motion. To decrease imaging time, multiple spin-echo acquisitions can be incorporated into radial sequences. In this case, different radial lines of Fourier data have different TE times and the resulting images can contain streaking ...

journal_title：Magnetic resonance in medicine

authors： Theilmann RJ,Gmitro AF,Altbach MI,Trouard TP

更新日期：2004-04-01 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：:High permittivity "dielectric pads" have been shown to increase image quality at high magnetic fields in regions of low radiofrequency transmit efficiency. This article presents a series of electromagnetic simulations to determine the effects of pad size and geometry, relative permittivity value, as well as thickness ...

journal_title：Magnetic resonance in medicine

authors： Teeuwisse WM,Brink WM,Haines KN,Webb AG

更新日期：2012-04-01 00:00:00

abstract：:T(2) -weighted, cardiac magnetic resonance imaging (T(2) w CMR) can be used to noninvasively detect and quantify the edematous region that corresponds to the area at risk (AAR) following myocardial infarction (MI). Previously, CMR has been used to examine structure and function in mice, expediting the study of genetic...

journal_title：Magnetic resonance in medicine

authors： Beyers RJ,Smith RS,Xu Y,Piras BA,Salerno M,Berr SS,Meyer CH,Kramer CM,French BA,Epstein FH

更新日期：2012-01-01 00:00:00

abstract：PURPOSE:Proof-of-concept study of mapping renal blood flow vector field according to the inverse solution to a mass transport model of time resolved tracer-labeled MRI data. THEORY AND METHODS:To determine tissue perfusion according to the underlying physics of spatiotemporal tracer concentration variation, the mass t...

journal_title：Magnetic resonance in medicine

authors： Zhou L,Zhang Q,Spincemaille P,Nguyen TD,Morgan J,Dai W,Li Y,Gupta A,Prince MR,Wang Y

更新日期：2021-04-01 00:00:00

abstract：PURPOSE:To demonstrate the feasibility of imaging a bolus of co-polarized [1-13 C]pyruvate and 13 C-urea to simultaneously assess both metabolism and perfusion in the rodent heart. METHODS:Copolarized [1-13 C]pyruvate and 13 C-urea was imaged using a multi-echo, flow-sensitized spiral pulse sequence. Healthy rats were...

journal_title：Magnetic resonance in medicine

authors： Lau AZ,Miller JJ,Robson MD,Tyler DJ

更新日期：2017-01-01 00:00:00

abstract：:Standard MRI cine exams for the study of cardiac function are segmented over several heartbeats and thus require a breath-hold to minimize breathing motion artifacts, which is a current limitation of this approach. The purpose of this study was to develop a method for the measurement and correction of respiratory moti...

journal_title：Magnetic resonance in medicine

authors： Leung AO,Paterson I,Thompson RB

更新日期：2008-09-01 00:00:00

abstract：:A radiofrequency (RF) time-domain electron paramagnetic resonance (EPR) instrument operating at 300, 600, and 750 MHz was used to image tumor hypoxia with high spatial and temporal resolution. A high-speed signal-averaging Peripheral Component Interconnect (PCI) board with flexibility in the input signal level and the...

journal_title：Magnetic resonance in medicine

authors： Devasahayam N,Subramanian S,Murugesan R,Hyodo F,Matsumoto K,Mitchell JB,Krishna MC

更新日期：2007-04-01 00:00:00

abstract：PURPOSE:The optic nerve (ON) represents the sole pathway between the eyes and brain; consequently, diseases of the ON can have dramatic effects on vision. However, quantitative magnetization transfer (qMT) applications in the ON have been limited to ex vivo studies, in part because of the fatty connective tissue that s...

journal_title：Magnetic resonance in medicine

authors： Smith AK,Dortch RD,Dethrage LM,Lyttle BD,Kang H,Welch EB,Smith SA

更新日期：2017-02-01 00:00:00

abstract：:T2 relaxation time is a promising MRI parameter for the detection of cartilage degeneration in osteoarthritis. However, the accuracy and precision of the measured T2 may be substantially impaired by the low signal-to-noise ratio of images available from clinical examinations. The purpose of this work was to assess the...

journal_title：Magnetic resonance in medicine

authors： Raya JG,Dietrich O,Horng A,Weber J,Reiser MF,Glaser C

更新日期：2010-01-01 00:00:00

abstract：:Successful radiofrequency (RF) thermal ablation was performed on VX2 tumors implanted in 23 rabbit livers under magnetic resonance (MR) guidance using a C-arm-shaped low-field 0.2 T system. RF application and immediate postprocedure MRI of all animals was performed [T2-weighted, turbo short tau inversion recovery (STI...

journal_title：Magnetic resonance in medicine

authors： Merkle EM,Boll DT,Boaz T,Duerk JL,Chung YC,Jacobs GH,Varnes ME,Lewin JS

更新日期：1999-07-01 00:00:00

abstract：:This work helps elucidate how background noise introduces statistical artifacts in the distribution of the sorted eigenvalues and eigenvectors in diffusion tensor MRI (DT-MRI) data. Although it was known that sorting eigenvalues (principal diffusivities) by magnitude introduces a bias in their sample mean within a hom...

journal_title：Magnetic resonance in medicine

authors： Basser PJ,Pajevic S

更新日期：2000-07-01 00:00:00

abstract：:Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function...

journal_title：Magnetic resonance in medicine

authors： Hänicke W,Vogel HU

更新日期：2003-04-01 00:00:00

abstract：:Although promising for visualizing the structure of ordered tissues, MR diffusion tensor imaging (DTI) has been hampered by long acquisition time and low spatial resolution associated with its inherently low signal-to-noise ratio (SNR). Moreover, the uncertainty in the DTI measurements has a direct impact on the accur...

journal_title：Magnetic resonance in medicine

authors： Chen B,Hsu EW

更新日期：2005-08-01 00:00:00

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: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：:A new k-space direct matrix inversion (DMI) method is proposed here to accelerate non-Cartesian SENSE reconstructions. In this method a global k-space matrix equation is established on basic MRI principles, and the inverse of the global encoding matrix is found from a set of local matrix equations by taking advantage ...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Zhang Z,Wang Y,Boada FE

更新日期：2006-08-01 00:00:00

abstract：:This paper presents an improved data reconstruction method for generalized autocalibrating partially parallel acquisitions (GRAPPA) using multicolumn multiline interpolation (MCMLI). Both nearest acquired line (ky) neighboring points and column (kx) neighboring points from all components of an array coil were used to ...

journal_title：Magnetic resonance in medicine

authors： Wang Z,Wang J,Detre JA

更新日期：2005-09-01 00:00:00

abstract：:Parameter-selective imaging for tissue characterization is performed at low magnetic fields (0.24-0.28 T) employing echo trains with a large number of echoes (less than or equal to 50), high-power pulses, and the projection reconstruction method. Preprocessing of the raw echoes is important for the quality of the echo...

journal_title：Magnetic resonance in medicine

authors： Staemmler M,Gersonde K

更新日期：1986-06-01 00:00:00

abstract：:The advent of event-related functional magnetic resonance imaging (fMRI) has resulted in many exciting studies that have exploited its unique capability. However, the utility of event-related fMRI is still limited by several technical difficulties. One significant limitation in event-related fMRI is the low signal-to-...

journal_title：Magnetic resonance in medicine

authors： LaConte SM,Ngan SC,Hu X

更新日期：2000-11-01 00:00:00

abstract：:Current implementations of coronary artery magnetic resonance angiography (MRA) suffer from limited coverage of the coronary arterial system. Whole-heart coronary MRA was implemented based on a free-breathing steady-state free-precession (SSFP) technique with magnetization preparation. The technique was compared to a ...

journal_title：Magnetic resonance in medicine

authors： Weber OM,Martin AJ,Higgins CB

更新日期：2003-12-01 00:00:00

abstract：:The previously reported concept for quantitative magnetization transfer (MT) imaging using balanced steady-state free precession (SSFP) is applied to nonbalanced SSFP sequences. This offers the possibility to derive quantitative MT parameters of targets with high-susceptibility variations such as the musculoskeletal s...

journal_title：Magnetic resonance in medicine

authors： Gloor M,Scheffler K,Bieri O

更新日期：2010-07-01 00:00:00

abstract：PURPOSE:To develop the simultaneous acquisition of multiple voxels in localized MR spectroscopy (MRS) using sensitivity encoding, allowing reduced total scan time compared to conventional sequential single voxel (SV) acquisition methods. METHODS:Dual volume localization was used to simultaneously excite voxels in both...

journal_title：Magnetic resonance in medicine

authors： Boer VO,Klomp DW,Laterra J,Barker PB

更新日期：2015-09-01 00:00:00

abstract：:Quantitative diffusion measurements were performed in tumors arising from inoculation of nude mice with two human breast cancer cell lines (MCF7 and T47D) to evaluate the specificity of this technique for characterizing solid tumors. ADC maps were compared to histology and correlated well with gross tumor morphology. ...

journal_title：Magnetic resonance in medicine

authors： Maier CF,Paran Y,Bendel P,Rutt BK,Degani H

更新日期：1997-04-01 00:00:00