Spin-locking versus chemical exchange saturation transfer MRI for investigating chemical exchange process between water and labile metabolite protons.

abstract：PURPOSE:In typical MRI protocols, time is spent acquiring a field map to calculate the shim settings for best image quality. We propose a fast template-based field map prediction method that yields near-optimal shims without measuring the field. METHODS:The template-based prediction method uses prior knowledge of the ...

journal_title：Magnetic resonance in medicine

authors： Shi Y,Vannesjo SJ,Miller KL,Clare S

更新日期：2018-07-01 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：:A new strategy for a quantitative measurement of regional pulmonary ventilation using hyperpolarized helium-3 (3He) MRI has been developed. The method employs the build-up of the signal intensity after a variable number of (3)He breaths. A mathematical model of the signal dynamics is presented, from which the local ve...

journal_title：Magnetic resonance in medicine

authors： Deninger AJ,Månsson S,Petersson JS,Pettersson G,Magnusson P,Svensson J,Fridlund B,Hansson G,Erjefeldt I,Wollmer P,Golman K

更新日期：2002-08-01 00:00:00

abstract：:Accumulation of lipids in atherosclerotic plaques causes progressive narrowing of the arterial lumen, often followed by thrombosis and ischemia. Currently several different methods, most requiring disruption of the plaque, are used to study the physical properties of lipids accumulated in plaques, and lipid compositio...

journal_title：Magnetic resonance in medicine

authors： Guo W,Morrisett JD,Lawrie GM,DeBakey ME,Hamilton JA

更新日期：1998-02-01 00:00:00

abstract：PURPOSE:We demonstrate the feasibility of MRI with missing-pulse steady-state free precession (MP-SSFP) in a 4T magnet with artificially degraded homogeneity. METHODS:T1 , T2 , and diffusion contrast of MP-SSFP was simulated with constant and alternate radiofrequency (RF) phase using an extended phase graph. To valida...

journal_title：Magnetic resonance in medicine

authors： Kobayashi N,Parkinson B,Idiyatullin D,Adriany G,Theilenberg S,Juchem C,Garwood M

更新日期：2021-02-01 00:00:00

abstract：:To increase image acquisition efficiency, we develop alternative gradient encoding strategies designed to provide spatial encoding complementary to the spatial encoding provided by the multiple receiver coil elements in parallel image acquisitions. Intuitively, complementary encoding is achieved when the magnetic fiel...

journal_title：Magnetic resonance in medicine

authors： Tam LK,Stockmann JP,Galiana G,Constable RT

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:Despite the increasing understanding of major depressive disorder (MDD) using neuroimaging techniques, the topological organization of anatomical networks underlying MDD remains unclear. METHODS:The topological organization of brain anatomical networks was explored using complex network approaches. Diffusion t...

journal_title：Magnetic resonance in medicine

authors： Qin J,Wei M,Liu H,Yan R,Luo G,Yao Z,Lu Q

更新日期：2014-11-01 00:00:00

abstract：:With diffusion tensor imaging, the diffusion of water molecules through brain structures is quantified by parameters, which are estimated assuming monoexponential diffusion-weighted signal attenuation. The estimated diffusion parameters, however, depend on the diffusion weighting strength, the b-value, which hampers t...

journal_title：Magnetic resonance in medicine

authors： Veraart J,Poot DH,Van Hecke W,Blockx I,Van der Linden A,Verhoye M,Sijbers J

更新日期：2011-01-01 00:00:00

abstract：:A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnet...

journal_title：Magnetic resonance in medicine

authors： Song T,Stainsby JA,Ho VB,Hood MN,Slavin GS

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:Imaging of [2-13 C]lactate, a metabolic product of [2-13 C]pyruvate, is over considerable interest in hyperpolarized 13 C studies. However, artifact-free imaging of a J-coupled nuclear spin species can be challenging due to the peak-splitting induced by the spin-spin interactions. In this work, two new techniqu...

journal_title：Magnetic resonance in medicine

authors： Datta K,Spielman D

更新日期：2021-03-01 00:00:00

abstract：:It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2...

journal_title：Magnetic resonance in medicine

authors： Nieminen MT,Rieppo J,Töyräs J,Hakumäki JM,Silvennoinen J,Hyttinen MM,Helminen HJ,Jurvelin JS

更新日期：2001-09-01 00:00:00

abstract：PURPOSE:Blood flow causes induced voltages via the magnetohydrodynamic (MHD) effect distorting electrograms (EGMs) made during magnetic resonance imaging. To investigate the MHD effect in this context MHD voltages occurring inside the human heart were simulated in an in vitro model system inside a 1.5 T MR system. MET...

journal_title：Magnetic resonance in medicine

authors： Buchenberg WB,Mader W,Hoppe G,Lorenz R,Menza M,Büchert M,Timmer J,Jung B

更新日期：2015-09-01 00:00:00

abstract：:Functional magnetic resonance imaging (fMRI) has recently been adopted as an investigational tool in the field of neuroscience. The signal changes induced by brain activations are small ( approximately 1-2%) at 1.5T. Therefore, the signal-to-noise ratio (SNR) of the time series used to calculate the functional maps is...

journal_title：Magnetic resonance in medicine

authors： Parrish TB,Gitelman DR,LaBar KS,Mesulam MM

更新日期：2000-12-01 00:00:00

abstract：:A comparison between contrast and signal-to-noise ratio (SNR), as obtained by both maximum entropy (ME) and 2DFT reconstruction, is reported for NMR images. Our results show that in the ME elaboration the contrast and SNR are generally increased with respect to the 2DFT elaboration. The magnitude of such an increase d...

journal_title：Magnetic resonance in medicine

authors： De Simone BC,De Luca F,Maraviglia B

更新日期：1988-11-01 00:00:00

abstract：PURPOSE:To improve the quality and speed of electron paramagnetic resonance imaging (EPRI) acquisition by combining a uniform sampling distribution with spinning gradient acquisition. THEORY AND METHODS:A uniform sampling distribution was derived for spinning gradient EPRI acquisition (uniform spinning sampling, USS) ...

journal_title：Magnetic resonance in medicine

authors： Johnson DH,Ahmad R,Liu Y,Chen Z,Samouilov A,Zweier JL

更新日期：2014-02-01 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：:Homogeneous soft tissue, as regards its magnetic relaxation properties, is well-modeled by solutions of cross-linked protein (see Koenig and Brown, Prog. NMR Spectr. 22, 487 (1991)). Interactions at the solute-solvent interface alter the hydrodynamics of solvent water, and also couple the solute and solvent proton Zee...

journal_title：Magnetic resonance in medicine

authors： Koenig SH,Brown RD 3rd

更新日期：1993-12-01 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：PURPOSE:Multi-echo spin-echo (MSE) transverse relaxometry mapping using multi-component models is used to study disease activity in neuromuscular disease by assessing the T2 of the myocytic component (T2water ). Current extended phase graph algorithms are not optimized for fat fractions above 50% and the effects of ina...

journal_title：Magnetic resonance in medicine

authors： Keene KR,Beenakker JM,Hooijmans MT,Naarding KJ,Niks EH,Otto LAM,van der Pol WL,Tannemaat MR,Kan HE,Froeling M

更新日期：2020-11-01 00:00:00

abstract：:Functional magnetic resonance imaging in real time is an emerging tool for the assessment of dynamic changes in brain activation. The short response latency (tens of seconds) renders the technique more sensitive to motion artifacts. Motion correction in real time requires computationally efficient algorithms which can...

journal_title：Magnetic resonance in medicine

authors： Mathiak K,Posse S

更新日期：2001-01-01 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 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：:Accelerated magnetic resonance imaging techniques reduce signal acquisition time by undersampling k-space. A fundamental problem in accelerated magnetic resonance imaging is the recovery of quality images from undersampled k-space data. Current state-of-the-art recovery algorithms exploit the spatial and temporal stru...

journal_title：Magnetic resonance in medicine

authors： Asif MS,Hamilton L,Brummer M,Romberg J

更新日期：2013-09-01 00:00:00

abstract：:A simple theoretical model was developed to compare the sensitivities (i.e., signal-to-noise ratios per unit imaging time) of two-dimensional (2D) multislice and 3D imaging sequences. The model shows that the sensitivities of 3D and 2D multislice MRI sequences are usually similar. Sensitivities are identical in T2-wei...

journal_title：Magnetic resonance in medicine

authors： Johnson G,Wadghiri YZ,Turnbull DH

更新日期：1999-04-01 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：PURPOSE:To determine whether neurochemical concentrations obtained at two MRI sites using clinical 3T scanners can be pooled when a highly optimized, nonvendor short-echo, single-voxel proton MRS pulse sequence is used in conjunction with identical calibration and quantification procedures. METHODS:A modified semi-LAS...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Adanyeguh IM,Emir UE,Nguyen TM,Valabregue R,Henry PG,Mochel F,Öz G

更新日期：2015-05-01 00:00:00

abstract：PURPOSE:Treatments using high-intensity focused ultrasound (HIFU) in the abdominal region remain challenging as a result of respiratory organ motion. A novel method is described here to achieve 3D motion-compensated ultrasound (US) MR-guided HIFU therapy using simultaneous ultrasound and MRI. METHODS:A truly hybrid US...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Manasseh G,Petrusca L,Scheffler K,Auboiroux V,Crowe LA,Hyacinthe JN,Natsuaki Y,Santini F,Becker CD,Terraz S,Bieri O,Salomir R

更新日期：2018-05-01 00:00:00

abstract：:Diffusion tensor imaging (DTI) is a new imaging modality that can provide unique information on brain white matter anatomy. Measurements of water diffusion constant along multiple axes are fitted to a tensor model, from which the diffusion anisotropy and dominant fiber orientation can be estimated. Even though the ten...

journal_title：Magnetic resonance in medicine

authors： Zhang J,van Zijl PC,Mori S

更新日期：2006-02-01 00:00:00

abstract：:The proton T(1) was measured at 132 μT in ex vivo prostate tissue specimens from radical prostatectomies of 35 patients with prostate cancer. Each patient provided two specimens. The NMR and MRI measurements involved proton repolarization, a field of typically 150 mT and detection of the 5.6-kHz signal with a supercon...

journal_title：Magnetic resonance in medicine

authors： Busch S,Hatridge M,Mößle M,Myers W,Wong T,Mück M,Chew K,Kuchinsky K,Simko J,Clarke J

更新日期：2012-04-01 00:00:00

abstract：:Double wave vector diffusion weighting uses gradients along two different directions between excitation and acquisition. It has been shown theoretically that for restricted diffusion the signal amplitude in such an experiment can depend on the angle between the two gradient vectors. The highest amplitude is obtained w...

journal_title：Magnetic resonance in medicine

authors： Koch MA,Finsterbusch J

更新日期：2008-07-01 00:00:00