Comprehensive quantification of signal-to-noise ratio and g-factor for image-based and k-space-based parallel imaging reconstructions.

abstract：:The purpose of this study was the simulation and measurement of balanced steady-state free precession (bSSFP) slice profiles for a detailed analysis of the influence of off-resonance effects on slice profile shape and bSSFP signal intensity. Due to the frequency response function of the bSSFP sequence, measurements th...

journal_title：Magnetic resonance in medicine

authors： Staehle F,Leupold J,Hennig J,Markl M

更新日期：2008-05-01 00:00:00

abstract：:A modular, user-friendly computer simulation of NMR imaging was created for the DEC VAX computer. This simulation is novel in that complex imaging phenomena, such as chemical shifts and flow, may be easily studied. Other features include spin warp and backprojection imaging, movie generation, and simulation of image c...

journal_title：Magnetic resonance in medicine

authors： Summers RM,Axel L,Israel S

更新日期：1986-06-01 00:00:00

abstract：:The authors describe a method for accurate in vivo multislice imaging of the active component of the B1 field which is based on a previously proposed method, which uses the signal intensity ratio of two images measured with different excitation angles, and a repetition time TR 5 > or = 5 T1. The new method essentially...

journal_title：Magnetic resonance in medicine

authors： Stollberger R,Wach P

更新日期：1996-02-01 00:00:00

abstract：:Multiple images acquired simultaneously from an array of surface coils can be combined to give a composite image with an improved signal-to-noise ratio (SNR) and a large field of view. The composite images' SNR can be optimized by taking advantage of noise correlations between coils and phase shifts induced by surface...

journal_title：Magnetic resonance in medicine

authors： Hayes CE,Roemer PB

更新日期：1990-11-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 00:00:00

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

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

更新日期：2016-01-01 00:00:00

abstract：:A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV-MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume fo...

journal_title：Magnetic resonance in medicine

authors： Pisani L,Bammer R,Glover G

更新日期：2007-02-01 00:00:00

abstract：:Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevert...

journal_title：Magnetic resonance in medicine

authors： Lin FH,Wang FN,Ahlfors SP,Hämäläinen MS,Belliveau JW

更新日期：2007-10-01 00:00:00

abstract：:Subject motion during scan is a major source of artifacts in MR examinations. Prospective motion correction is a promising technique that tracks subject motion and adjusts the imaging volume in real time; however, additional retrospective correction may be necessary to achieve robust image quality and compatibility wi...

journal_title：Magnetic resonance in medicine

authors： Banerjee S,Beatty PJ,Zhang JZ,Shankaranarayanan A

更新日期：2013-02-01 00:00:00

abstract：PURPOSE:The feasibility of imaging musculoskeletal fibrous tissue components, such as menisci, ligaments, and tendons, with a conventional spoiled gradient echo technique is explored in vivo at 3 T and 7 T. METHODS:To this end, the echo time (TE1 ) of a conventional Fourier-encoded multicontrast three-dimensional SGPR...

journal_title：Magnetic resonance in medicine

authors： Deligianni X,Bär P,Scheffler K,Trattnig S,Bieri O

更新日期：2013-11-01 00:00:00

abstract：PURPOSE:To develop a pulsed CEST magnetization-transfer method for rapidly acquiring relayed nuclear Overhauser enhancement (rNOE)-weighted images with magnetic transfer contrast (MTC) suppression at clinical field strength (3 T). METHODS:Using a pulsed CEST magnetization-transfer method with low saturation powers (B1...

journal_title：Magnetic resonance in medicine

authors： Huang J,Han X,Chen L,Xu X,Xu J,Chan KWY

更新日期：2021-01-01 00:00:00

abstract：:The acquisition of complete three-dimensional (3D), segmented gradient-echo data sets to visualize the coronary arteries can be both time consuming and sensitive to motion, even with use of multiple breath-holding or respiratory gating. An alternate hybrid approach is demonstrated here, in which real-time interactive ...

journal_title：Magnetic resonance in medicine

authors： Hardy CJ,Darrow RD,Pauly JM,Kerr AB,Dumoulin CL,Hu BS,Martin KM

更新日期：1998-07-01 00:00:00

abstract：PURPOSE:Classification of pediatric brain tumors from 1 H-magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed diffe...

journal_title：Magnetic resonance in medicine

authors： Zarinabad N,Wilson M,Gill SK,Manias KA,Davies NP,Peet AC

更新日期：2017-06-01 00:00:00

abstract：:31P NMR of superfused resting cartilage demonstrated the presence of phosphocreatine in chondrocytes. Changes in pH and in the NTP level were followed during carbon source starvation. From 31P spectra of perchloric acid extracts, phosphoethanolamine, phosphocholine, and the corresponding glycerol diesters were identif...

journal_title：Magnetic resonance in medicine

authors： Kvam BJ,Pollesello P,Vittur F,Paoletti S

更新日期：1992-06-01 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：:In this study, we report the use of a novel ultrashort echo time T(1)rhoT(1) sequence that combines a spin-lock preparation pulse with a two-dimensional ultrashort echo time sequence of a nominal echo time 8 microsec. The ultrashort echo time-T(1)rho sequence was employed to quantify T(1)rho in short T(2) tissues incl...

journal_title：Magnetic resonance in medicine

authors： Du J,Carl M,Diaz E,Takahashi A,Han E,Szeverenyi NM,Chung CB,Bydder GM

更新日期：2010-09-01 00:00:00

abstract：PURPOSE:Evaluate the usefulness of single-shot and of interleaved spatiotemporally encoded (SPEN) methods to perform diffusion tensor imaging (DTI) under various preclinical and clinical settings. METHODS:A formalism for analyzing SPEN DTI data is presented, tailored to account for the spatially dependent b-matrix wei...

journal_title：Magnetic resonance in medicine

authors： Solomon E,Liberman G,Nissan N,Frydman L

更新日期：2017-03-01 00:00:00

abstract：:This study presents the detection of [2-(13)C]glucose metabolism in the carboxylic/amide region in the human brain, and demonstrates that the cerebral metabolism of [2-(13)C]glucose can be studied in human subjects in the presence of severe hardware constraints of widely available 3 T clinical scanners and with low-po...

journal_title：Magnetic resonance in medicine

authors： Li S,Zhang Y,Wang S,Yang J,Ferraris Araneta M,Farris A,Johnson C,Fox S,Innis R,Shen J

更新日期：2009-09-01 00:00:00

abstract：:The utility of MRI using magnetization transfer (MT) enhanced pulse sequences to diagnose hepatic cirrhosis in a rat model was investigated. Hepatic T1 was measured with and without MT off-resonance RF pulses in 17 treated and six control rats. The livers were evaluated histologically, and the hydroxyproline content q...

journal_title：Magnetic resonance in medicine

authors： Aisen AM,Doi K,Swanson SD

更新日期：1994-05-01 00:00:00

abstract：:Certain kinds of artifacts have been reported when projection reconstruction (PR) techniques are used in magnetic resonance imaging (MRI). These will occur if the spacing between samples in k-space is too large. It has been suggested that PR requires finer k-space sampling than does two-dimensional Fourier reconstruct...

journal_title：Magnetic resonance in medicine

authors： Joseph PM

更新日期：1998-09-01 00:00:00

abstract：:Atherosclerosis initially develops predominantly at the aortic root and carotid origin, where effective visualization in mice requires efficient cardiac and respiratory gating. The present study sought to first compare the high-resolution MRI gating performance of two digital gating strategies using: 1) separate cardi...

journal_title：Magnetic resonance in medicine

authors： Alsaid H,Sabbah M,Bendahmane Z,Fokapu O,Felblinger J,Desbleds-Mansard C,Corot C,Briguet A,Crémillieux Y,Canet-Soulas E

更新日期：2007-12-01 00:00:00

abstract：PURPOSE:Atherosclerotic carotid plaques can be quantified in vivo by MRI. However, the accuracy in segmentation and quantification of components such as the thin fibrous cap (FC) and lipid-rich necrotic core (LRNC) remains unknown due to the lack of a submillimeter scale ground truth. METHODS:A novel approach was take...

journal_title：Magnetic resonance in medicine

authors： Nieuwstadt HA,Geraedts TR,Truijman MT,Kooi ME,van der Lugt A,van der Steen AF,Wentzel JJ,Breeuwer M,Gijsen FJ

更新日期：2014-07-01 00:00:00

abstract：PURPOSE:The clinical potential of the diffusion imaging-based analysis of fine brain structures such as fornix or cingulum is high due to the central role of these structures in psychiatric diseases. However, the quantification of diffusion parameters in fine structures is especially prone to partial volume effects (PV...

journal_title：Magnetic resonance in medicine

authors： Bach M,Fritzsche KH,Stieltjes B,Laun FB

更新日期：2014-03-01 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：:We describe a doubly tuned radiofrequency (RF) local coil probe designed specifically for performing in vivo image-localized spectroscopy. The probe was designed using principles developed in connection with the counter-rotating-current (CRC) and planar-pair loop gap resonators for magnetic resonance imaging (MRI). Th...

journal_title：Magnetic resonance in medicine

authors： Grist TM,Jesmanowicz A,Kneeland JB,Froncisz W,Hyde JS

更新日期：1988-03-01 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：:Manganese is a useful contrast agent for MRI of animals. Previously, it has been shown that systemic doses of MnCl(2) provide unique contrast in the rodent brain, enabling visualization of neuroarchitecture. The present work investigates the dose and temporal dependence of brain enhancement after i.v. administration o...

journal_title：Magnetic resonance in medicine

authors： Lee JH,Silva AC,Merkle H,Koretsky AP

更新日期：2005-03-01 00:00:00

abstract：:It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using ...

journal_title：Magnetic resonance in medicine

authors： Riauka TA,De Zanche NF,Thompson R,Vermeulen FE,Capjack CE,Allen PS

更新日期：1999-06-01 00:00:00

abstract：:Follow-up T(1)-weighted 3D gradient-echo MRI (2.35 T) of murine brain in vivo (N = 5) at 120 microm isotropic resolution revealed spatially distinct signal increases 6-48 hr after subcutaneous application of MnCl(2) (20 mg/kg). The effects result from a shortening of the water proton T(1) relaxation time due to the pr...

journal_title：Magnetic resonance in medicine

authors： Watanabe T,Natt O,Boretius S,Frahm J,Michaelis T

更新日期：2002-11-01 00:00:00

abstract：:We have demonstrated that echo-planar imaging can be used to produce high-quality snapshot images of the human fetus in utero in a fraction of a second. These images are free of motional artifact or blurring and allow detailed depiction of fetal structures in normal and pathological pregnancies. ...

journal_title：Magnetic resonance in medicine

authors： Stehling MK,Mansfield P,Ordidge RJ,Coxon R,Chapman B,Blamire A,Gibbs P,Johnson IR,Symonds EM,Worthington BS

更新日期：1990-02-01 00:00:00