T2 measurement in articular cartilage: impact of the fitting method on accuracy and precision at low SNR.

abstract：:The relaxation of (1)H nuclei due to their interaction with quadrupolar (14)N nuclei in gel structures is measured using fast field-cycling NMR. This phenomenon called quadrupolar dips has been reported in different (1)H-(14)N bond-rich species. In this study, we have studied quadrupolar dips in fibrin, an insoluble p...

journal_title：Magnetic resonance in medicine

authors： Broche LM,Ismail SR,Booth NA,Lurie DJ

更新日期：2012-05-01 00:00:00

abstract：:Proton MR spectroscopy ((1)H-MRS) has been used for in vivo quantification of intracellular triglycerides within the sarcolemma. The purpose of this study was to assess whether breath-hold dual-echo in- and out-of-phase MRI at 3.0 T can quantify the fat content of the myocardium. Biases, including T(1), T*(2), and noi...

journal_title：Magnetic resonance in medicine

authors： Liu CY,Redheuil A,Ouwerkerk R,Lima JA,Bluemke DA

更新日期：2010-04-01 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：PURPOSE:To develop methods for characterizing materials used in screen-printed MRI coils and improve signal-to-noise ratio (SNR) with new lower-loss materials. METHODS:An experimental apparatus was created to characterize dielectric properties of plastic substrates used in receive coils. Coils were fabricated by scree...

journal_title：Magnetic resonance in medicine

authors： Corea JR,Lechene PB,Lustig M,Arias AC

更新日期：2017-08-01 00:00:00

abstract：:The use of the minimum stored energy current density map-based methodology of designing closed-bore symmetric superconducting magnets was described recently. The technique is further developed to cater for the design of interventional-type MRI systems, and in particular open symmetric magnets of the double-doughnut co...

journal_title：Magnetic resonance in medicine

authors： Tieng QM,Vegh V,Brereton IM

更新日期：2010-01-01 00:00:00

abstract：:The cytosol of intact human red blood cells was loaded with 28.1 +/- 3.4 mM of dysprosium DTPA-BMA using a hypoosmotic technique. When loaded cells were diluted with saline and control cells to give an average dysprosium concentration of 3.3 +/- 0.5 mM, the transverse relaxation rate constants R(*)(2) and R(2) increas...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Tao JZ,Kennan RP,Gore JC

更新日期：2001-05-01 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：: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：: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：:Spin-echo images of 10 myocardial infarcts in nine mini-pigs were obtained at 30 h, 3 days, and approximately 10 days postinfarction. Infarcts were not detected at all at 30 h in five out of five cases examined. At 3 days postembolization (six cases) one infarct was certainly detected, whilst at 10 days (nine cases) a...

journal_title：Magnetic resonance in medicine

authors： Checkley D,Loveday BE,Waterton JC,Zhu XP,Isherwood I

更新日期：1987-09-01 00:00:00

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：:The study of lung perfusion in normal and diseased subjects is of great interest to physiologists and physicians. In this work we demonstrate the application of a liquid-phase hyperpolarized (HP) carbon-13 ((13)C) tracer to magnetic resonance imaging (MRI) of the pulmonary vasculature and pulmonary perfusion in a porc...

journal_title：Magnetic resonance in medicine

authors： Ishii M,Emami K,Kadlecek S,Petersson JS,Golman K,Vahdat V,Yu J,Cadman RV,MacDuffie-Woodburn J,Stephen M,Lipson DA,Rizi RR

更新日期：2007-03-01 00:00:00

abstract：PURPOSE:A direct method of imaging neural activity was simulated to determine typical signal sizes. METHODS:An active bidomain finite-element model was used to estimate approximate perturbations in MR phase data as a result of neural tissue activity, and when an external MR electrical impedance tomography imaging curr...

journal_title：Magnetic resonance in medicine

authors： Sadleir RJ,Fu F,Chauhan M

更新日期：2019-01-01 00:00:00

abstract：:A multifocal mouse liver tumor model chemically induced with 5,9-dimethyl-7H-dibenzo[c,g]carbazole was investigated by respiratory-triggered morphological and functional MRI (fMRI) at 4.7 Tesla. The model is characterized by the presence of two tumor types: hypovascular cholangioma and vascularized hepatocellular carc...

journal_title：Magnetic resonance in medicine

authors： Thomas CD,Chenu E,Walczak C,Plessis MJ,Perin F,Volk A

更新日期：2003-09-01 00:00:00

abstract：PURPOSE:This assesses the potential of measuring lactate in the human brain using three non-editing MRS methods at 7T and compares the accuracy and precision of the methods. METHODS:1 H MRS data were measured in the right dorsolateral prefrontal cortex using a semi-adiabatic spin-echo full-intensity acquired localized...

journal_title：Magnetic resonance in medicine

authors： Dehghani M,Do KQ,Magistretti P,Xin L

更新日期：2020-06-01 00:00:00

abstract：:Quantitative cerebral tissue volumes may be useful for an objective assessment of pathological changes in brain. Accurate determination of tissue volumes is complicated, however, by the partial volume averaging (PVA) effect. We have, therefore, developed a new pulse sequence that minimizes the PVA through the use of i...

journal_title：Magnetic resonance in medicine

authors： Bedell BJ,Narayana PA

更新日期：1998-06-01 00:00:00

abstract：:MRI using hyperpolarized (13) C-labeled pyruvate is a promising tool to biochemically profile tumors and monitor their response to therapy. This technique requires injection of pyruvate into tumor-bearing animals. Pyruvate is an endogenous entity but the influence of exogenously injected bolus doses of pyruvate on tum...

journal_title：Magnetic resonance in medicine

authors： Saito K,Matsumoto S,Devasahayam N,Subramanian S,Munasinghe JP,Morris HD,Lizak MJ,Ardenkjaer-Larsen JH,Mitchell JB,Krishna MC

更新日期：2012-03-01 00:00:00

abstract：:Combining positron emission tomography and MRI modalities typically requires using either conventional MRI with a MR-compatible positron emission tomography system or a modified MR system with conventional positron emission tomography. A feature of field-cycled MRI is that all magnetic fields can be turned off rapidly...

journal_title：Magnetic resonance in medicine

authors： Bindseil GA,Gilbert KM,Scholl TJ,Handler WB,Chronik BA

更新日期：2011-07-01 00:00:00

abstract：:High-order radiofrequency transmitter coils are described that permit, in the context of NMR imaging, a knowledgeable trade-off between coil complexity and the degree of inhomogeneity over a specified volume of space. A mathematical formulation of high-order coils is developed for an axially symmetric polarizing dc fi...

journal_title：Magnetic resonance in medicine

authors： Sotgiu A,Hyde JS

更新日期：1986-02-01 00:00:00

abstract：:The complexity of biologic tissues, with multiple compartments each with its own diffusion and relaxation properties, requires complex formalisms to model water signal in most magnetic resonance imaging or magnetic resonance spectroscopy experiments. In this article, we describe a magnetic susceptibility-induced shift...

journal_title：Magnetic resonance in medicine

authors： Galons JP,Lope-Piedrafita S,Divijak JL,Corum C,Gillies RJ,Trouard TP

更新日期：2005-07-01 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：PURPOSE:To investigate whether saturation using existing methods developed for 3T imaging is feasible for clinical perfusion imaging at 7T, and to propose a new design of saturation pulse train for first-pass myocardial perfusion imaging at 7T. METHODS:The new design of saturation pulse train consists of four hyperbol...

journal_title：Magnetic resonance in medicine

authors： Tao Y,Hess AT,Keith GA,Rodgers CT,Liu A,Francis JM,Neubauer S,Robson MD

更新日期：2015-04-01 00:00:00

abstract：:Functional MRI studies to date have been generally performed using the blood oxygenation level dependent (BOLD) contrast mechanism. Recently, it has been proposed that dynamic change in the apparent diffusion coefficient (ADC), measured using intravoxel incoherent motion (IVIM) weighting, can be used as a robust funct...

journal_title：Magnetic resonance in medicine

authors： Harshbarger TB,Song AW

更新日期：2004-12-01 00:00:00

abstract：PURPOSE:Investigation of the feasibility to perform high-resolution quantitative sodium imaging at 9.4 Tesla (T). METHODS:A proton patch antenna was combined with a sodium birdcage coil to provide a proton signal without compromising the efficiency of the X-nucleus coil. Sodium density weighted images with a nominal r...

journal_title：Magnetic resonance in medicine

authors： Mirkes CC,Hoffmann J,Shajan G,Pohmann R,Scheffler K

更新日期：2015-01-01 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：PURPOSE:Amide-proton transfer (APT) and amine-water proton exchange (APEX) MRI can be viable to map pH-decreasing ischemic regions. However, their exact contributions are unclear. METHODS:We measured APEX- and APT-weighted magnetization transfer ratio asymmetry (denoted as APEXw and APTw), apparent diffusion coefficie...

journal_title：Magnetic resonance in medicine

authors： Zong X,Wang P,Kim SG,Jin T

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:Compare the transmural distribution of forward creatine kinase reaction (kf,CK ) and ATP hydrolysis rate (kr,ATPase ) in the myocardium of normal porcine heart. Rate constants were extracted from partially relaxed spectra by applying the T1nom method, effectively reducing data acquisition time by up to an order...

journal_title：Magnetic resonance in medicine

authors： Jang A,Xiong Q,Zhang P,Zhang J

更新日期：2016-05-01 00:00:00

abstract：:Diffusion tensor imaging is gaining increasing importance for anatomical imaging of the developing mouse brain. However, the application of diffusion tensor imaging to mouse brain imaging at microscopic levels is hindered by the limitation on achievable spatial resolution. In this study, fast diffusion tensor microima...

journal_title：Magnetic resonance in medicine

authors： Aggarwal M,Mori S,Shimogori T,Blackshaw S,Zhang J

更新日期：2010-07-01 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：:If magnetic resonance spectroscopy (MRS) is to become a useful tool in clinical medicine, it will be necessary to find reliable methods for analyzing and classifying MRS data. Automated methods are desirable because they can remove user bias and can deal with large amounts of data, allowing the use of all the availabl...

journal_title：Magnetic resonance in medicine

authors： Tate AR,Watson D,Eglen S,Arvanitis TN,Thomas EL,Bell JD

更新日期：1996-06-01 00:00:00