Tilt optimized flip uniformity (TOFU) RF pulse for uniform image contrast at low specific absorption rate levels in combination with a surface breast coil at 7 Tesla.

abstract：:Diffusion-weighted MRI is a clinically useful technique, but its utility is compromised by high sensitivity to patient motion. Use of radial-scan data acquisition and projection reconstruction, rather than the conventional Fourier imaging method, can substantially reduce the sensitivity to global translational motion ...

journal_title：Magnetic resonance in medicine

authors： Gmitro AF,Alexander AL

更新日期：1993-06-01 00:00:00

abstract：PURPOSE:Respiratory organ motion is still the major challenge of various image-guided treatments in the abdomen. Dynamic organ motion tracking, necessary for the treatment control, can be performed with volumetric time-resolved MRI that sequentially acquires one image and one navigator slice. Here, a novel imaging meth...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Bieri O,Preiswerk F,Cattin P,Scheffler K,Santini F

更新日期：2015-02-01 00:00:00

abstract：:A novel method for reducing the rf power requirements of selective pulses employed for z magnetization slice inversion in localized NMR spectroscopy is presented. Following slice preparation by the use of frequency-incremented sinc pulses, the slice gradient is reduced, which narrows the frequency width of the slice. ...

journal_title：Magnetic resonance in medicine

authors： Brereton IM,Brooks WM,Marshman MF,Field J,Doddrell DM

更新日期：1987-12-01 00:00:00

abstract：:The eigenimage filter was used to evaluate the results of a MRI study of cerebral ischemia in a rat model. This linear filter segments a desired feature in an image sequence from other features which may interfere with its observation. The animals were imaged temporally, after occlusion of the middle cerebral artery, ...

journal_title：Magnetic resonance in medicine

authors： Peck DJ,Spickler EM,Knight RA,Hearshen DO,Windham JP

更新日期：1992-08-01 00:00:00

abstract：:1H MR spectra were recorded from human gastrocnemius muscle at 63.86 MHz using the body coil of the Signa scanner as transmitter and a 3-in. surface coil as receiver. The fat content of the muscle was quantified relative to that of water in a selected volume or slice. The fat/water ratio was 0.05-0.07 for normal muscl...

journal_title：Magnetic resonance in medicine

authors： Bárány M,Venkatasubramanian PN,Mok E,Siegel IM,Abraham E,Wycliffe ND,Mafee MF

更新日期：1989-05-01 00:00:00

abstract：:To quantify metabolite and cation concentrations using NMR spectroscopy, the volumes of intracellular and extracellular spaces must be known. We describe a simple 31P NMR spectroscopic method that employs dimethyl methylphosphonate (DMMP) as a marker of total water space and phenylphosphonate (PPA) as a marker of extr...

journal_title：Magnetic resonance in medicine

authors： Clarke K,Anderson RE,Nédélec JF,Foster DO,Ally A

更新日期：1994-08-01 00:00:00

abstract：PURPOSE:To assess the impact of a different distortion correction (DC) method and patient geometry (sagittal balance) on the quality of spinal cord tractography rendering according to different tractography approaches. METHODS:Forty-four adults free of spinal cord diseases underwent cervical diffusion-weighted imaging...

journal_title：Magnetic resonance in medicine

authors： Dauleac C,Bannier E,Cotton F,Frindel C

更新日期：2021-01-21 00:00:00

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

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

更新日期：2020-12-08 00:00:00

abstract：:Chemical shift-based multipoint water-fat separation methods have been applied in balanced steady-state free precession (bSSFP) sequences because of the high signal-to-noise-ratio (SNR) attainable. In this approach the echo formation is approximated to occur concurrently for both water and fat at an echo time (TE) equ...

journal_title：Magnetic resonance in medicine

authors： Kim H,Pinus AB,Wang J,Murphy PS,Constable RT

更新日期：2007-08-01 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：: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: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：PURPOSE:The apparent propagator anisotropy (APA) is a new diffusion MRI metric that, while drawing on the benefits of the ensemble averaged propagator anisotropy (PA) compared to the fractional anisotropy (FA), can be estimated from single-shell data. THEORY AND METHODS:Computation of the full PA requires acquisition ...

journal_title：Magnetic resonance in medicine

authors： Aja-Fernández S,Tristán-Vega A,Jones DK

更新日期：2020-12-13 00:00:00

abstract：:The reconstruction of MR images from nonrectilinearly sampled data is complicated by the fact that the inverse 2D Fourier transform (FT) cannot be performed directly on the acquired k-space data set. k-Space gridding is commonly used because it is an efficient reconstruction method. However, conventional gridding requ...

journal_title：Magnetic resonance in medicine

authors： Moriguchi H,Duerk JL

更新日期：2004-02-01 00:00:00

abstract：PURPOSE:Establishing a high-resolution non-ECG-gated first-pass perfusion (FPP) cardiac MRI technique may improve accessibility and diagnostic capability of FPP imaging. We propose a non-ECG-gated FPP imaging technique using continuous magnetization-driven golden-angle radial acquisition. The main purpose of this preli...

journal_title：Magnetic resonance in medicine

authors： Sharif B,Dharmakumar R,Arsanjani R,Thomson L,Bairey Merz CN,Berman DS,Li D

更新日期：2014-12-01 00:00:00

abstract：:A general analytical framework is presented for the design of birdcage radiofrequency resonators on cylindrical formers having arbitrary cross-sectional shape. The primary objective of such shapes would be to improve the sensitivity of the NMR experiment to noncircular regions of the human anatomy while maintaining fi...

journal_title：Magnetic resonance in medicine

authors： De Zanche N,Yahya A,Vermeulen FE,Allen PS

更新日期：2005-01-01 00:00:00

abstract：:The harmonic phase (HARP) method provides automatic and rapid analysis of tagged magnetic resonance (MR) images for quantification and visualization of myocardial strain. In this article, the development and implementation of a pulse sequence that acquires HARP images in real time are described. In this pulse sequence...

journal_title：Magnetic resonance in medicine

authors： Sampath S,Derbyshire JA,Atalar E,Osman NF,Prince JL

更新日期：2003-07-01 00:00:00

abstract：:Since contrast in magnetic resonance imaging (MRI) is so sensitive to the magnetic relaxation rates of tissue protons, the use of paramagnetic ions to alter contrast in a tissue-specific fashion is an alluring prospect. The influence of these ions on the proton relaxation rates in homogeneous solutions is known to var...

journal_title：Magnetic resonance in medicine

authors： Koenig SH,Brown RD 3rd,Goldstein EJ,Burnett KR,Wolf GL

更新日期：1985-04-01 00:00:00

abstract：PURPOSE:To investigate Shift Undersampling improves Parametric mapping Efficiency and Resolution (SUPER), a novel blockwise curve-fitting method for accelerating parametric mapping with very fast reconstruction. METHODS:SUPER uses interleaved k-space undersampling, which enables a blockwise decomposition of the otherw...

journal_title：Magnetic resonance in medicine

authors： Hu C,Peters DC

更新日期：2019-06-01 00:00:00

abstract：:A combined carbogen ultrasmall superparamagnetic iron oxide (USPIO) imaging protocol was developed and applied in vivo in two murine colorectal tumor xenograft models, HCT116 and SW1222, with established disparate vascular morphology, to investigate whether additional information could be extracted from the combinatio...

journal_title：Magnetic resonance in medicine

authors： Burrell JS,Walker-Samuel S,Baker LC,Boult JK,Ryan AJ,Waterton JC,Halliday J,Robinson SP

更新日期：2011-07-01 00:00:00

abstract：:In this study, the precision and accuracy of a new method for measuring axial rotations of the lumbar vertebrae, which are thought to be increased in patients with degenerative spinal instability, were estimated. A standard image registration algorithm involving a user-selected center of rotation was adapted for this ...

journal_title：Magnetic resonance in medicine

authors： Rogers BP,Haughton VM,Arfanakis K,Meyerand ME

更新日期：2002-12-01 00:00:00

abstract：:The relative distributions of N-acetylaspartate (NAA) + N-acetylaspartylglutamate (NAAG), creatine + phosphocreatine (Cr/PCr), and choline (Cho) in the gray and white matter of human brain were determined by utilizing proton magnetic resonance spectroscopic imaging (SI). The SI data was processed using an automated sp...

journal_title：Magnetic resonance in medicine

authors： Doyle TJ,Bedell BJ,Narayana PA

更新日期：1995-06-01 00:00:00

abstract：:A method for collecting MRI data on a set of rotated trajectories that begin at the center of k-space is outlined. It is theoretically slightly faster, slightly less susceptible to off-resonance and motion-induced phase, and produces images with slightly better signal-to-noise ratio than methods using Archimedean spir...

journal_title：Magnetic resonance in medicine

authors： Pipe JG

更新日期：1999-10-01 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：:The ability to directly detect neuronal magnetic fields by MRI would help investigators achieve the "holy grail" of neuroimaging, namely both high spatial and temporal resolution. Both positive and negative findings have been reported in the literature, with no clear consensus as to the feasibility of direct detection...

journal_title：Magnetic resonance in medicine

authors： Parkes LM,de Lange FP,Fries P,Toni I,Norris DG

更新日期：2007-02-01 00:00:00

abstract：:Time-resolved three-dimensional phase-contrast MRI is an important tool for physiological as well as clinical studies of blood flow in the heart and vessels. The application of the technique is, however, limited by the long scan times required. In this work, we investigate the feasibility of using spiral readouts to r...

journal_title：Magnetic resonance in medicine

authors： Sigfridsson A,Petersson S,Carlhäll CJ,Ebbers T

更新日期：2012-10-01 00:00:00

abstract：:It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...

journal_title：Magnetic resonance in medicine

authors： Alsop DC

更新日期：1997-02-01 00:00:00

abstract：:A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equatio...

journal_title：Magnetic resonance in medicine

authors： Olsson MB,Wirestam R,Persson BR

更新日期：1995-10-01 00:00:00

abstract：:A novel linear parameterization for the variable flip angle method for longitudinal relaxation time T(1) quantification from spoiled steady state MRI is derived from the half angle tangent transform, τ, of the flip angle. Plotting the signal S at coordinates x=Sτ and y=S/τ, respectively, establishes a line that render...

journal_title：Magnetic resonance in medicine

authors： Helms G,Dathe H,Weiskopf N,Dechent P

更新日期：2011-09-01 00:00:00

abstract：:In several applications, MRI is used to monitor the time behavior of the signal in an organ of interest; e.g., signal evolution because of physiological motion, activation, or contrast-agent accumulation. Dynamic applications involve acquiring data in a k-t space, which contains both temporal and spatial information. ...

journal_title：Magnetic resonance in medicine

authors： Madore B,Glover GH,Pelc NJ

更新日期：1999-11-01 00:00:00