Vascular transit times in calcarine cortex: kinetic analysis of R2* changes observed using localized 1H spectroscopy.

abstract：:This paper describes a technique for characterizing the gradient subsystem of a magnetic resonance (MR) system. The technique uses a Fourier-transform analysis to directly measure the k-space trajectory produced by an arbitrary gradient waveform. In addition, the method can be easily extended to multiple dimensions an...

journal_title：Magnetic resonance in medicine

authors： Alley MT,Glover GH,Pelc NJ

更新日期：1998-04-01 00:00:00

abstract：:The previously observed improvement in spectral resolution of tissue proton NMR with high-resolution magic angle spinning (HRMAS) was speculated to be due largely to freeze-thawing artifacts resulting from tissue storage. In this study, 12 human prostate samples were analyzed on a 14.1T spectrometer at 3 degrees C, wi...

journal_title：Magnetic resonance in medicine

authors： Wu CL,Taylor JL,He W,Zepeda AG,Halpern EF,Bielecki A,Gonzalez RG,Cheng LL

更新日期：2003-12-01 00:00:00

abstract：:This communication describes the design and application of a receiver coil operating at liquid nitrogen temperature and intended as a surface coil in a whole-body imager. Its particular application is seen as the external receiver for parasitic internal or implanted detectors. ...

journal_title：Magnetic resonance in medicine

authors： Hall AS,Barnard B,McArthur P,Gilderdale DJ,Young IR,Bydder GM

更新日期：1988-06-01 00:00:00

abstract：:This article describes an EPR spectrometer specifically designed and constructed for EPR spectroscopy in humans. The spectrometer is based on a permanent magnet, suitable for measurements at 1200 MHz. The magnet has a full 50 cm gap between the poles, which facilitates accurate and comfortable placement of the subject...

journal_title：Magnetic resonance in medicine

authors： Salikhov I,Walczak T,Lesniewski P,Khan N,Iwasaki A,Comi R,Buckey J,Swartz HM

更新日期：2005-11-01 00:00:00

abstract：:MRI of myocardial perfusion observed with an extracellular contrast agent has proven valuable for the detection of coronary artery disease. During contrast enhancement transient dark rim artifacts are sometimes visible, complicating diagnosis and quantification. In this work a quantification of the frequency offsets c...

journal_title：Magnetic resonance in medicine

authors： Ferreira P,Gatehouse P,Bucciarelli-Ducci C,Wage R,Firmin D

更新日期：2008-10-01 00:00:00

abstract：:For time-resolved background-subtracted contrast-enhanced magnetic resonance angiography, the bright and sparse arterial signal allows unique identification of contrast bolus arrival in the arteries. This article presents an automatic filtering algorithm using such arterial characterization for selecting arterial phas...

journal_title：Magnetic resonance in medicine

authors： Kim J,Prince MR,Zabih R,Bezanson J,Watts R,Erel HE,Wang Y

更新日期：2002-12-01 00:00:00

abstract：PURPOSE:This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. METHODS:Correlation imaging is a high-speed MRI framework in ...

journal_title：Magnetic resonance in medicine

authors： Li Y,Wang H,Tkach J,Roach D,Woods J,Dumoulin C

更新日期：2015-12-01 00:00:00

abstract：PURPOSE:To optimize and investigate the influence of bipolar gradients for flow suppression in metabolic quantification of hyperpolarized 13 C chemical shift imaging (CSI) of mouse liver at 9.4 T. METHODS:The trade-off between the amount of flow suppression using bipolar gradients and T2* effect from static spins was ...

journal_title：Magnetic resonance in medicine

authors： Lee H,Lee J,Joe E,Yang S,Song JE,Choi YS,Wang E,Joo CG,Song HT,Kim DH

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. THEORY AND METHODS:A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of ...

journal_title：Magnetic resonance in medicine

authors： Romu T,Dahlström N,Leinhard OD,Borga M

更新日期：2017-09-01 00:00:00

abstract：:Rapid flow imaging was achieved with a partial field of view (pFOV) spiral motion-encoded technique. The FOV and the acquisition time were reduced by a factor of 2 by undersampling k-space. The pFOV spiral k-space trajectory aliased signals from outside a circular ring whose radius was inversely proportional to the di...

journal_title：Magnetic resonance in medicine

authors： Nezafat R,Thompson RB,Derbyshire JA,McVeigh ER

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:The linear change of the water proton resonance frequency shift (PRFS) with temperature is used to monitor temperature change based on the temporal difference of image phase. Here, the effect of motion-induced susceptibility artifacts on the phase difference was studied in the context of mild radio frequency hy...

journal_title：Magnetic resonance in medicine

authors： Wu M,Mulder HT,Baron P,Coello E,Menzel MI,van Rhoon GC,Haase A

更新日期：2020-11-01 00:00:00

abstract：:Localized 7Li MR point-resolved spectroscopy (PRESS) was developed as a technique to measure lithium (Li) concentration in rat brain in vivo. Localized 7Li spectra could be obtained at 4.7 T in a 0.7-ml voxel in rat brain over the entire therapeutic range of serum Li for humans. Localized 7Li spin-lattice (T1) and spi...

journal_title：Magnetic resonance in medicine

authors： Komoroski RA,Pearce JM

更新日期：2004-07-01 00:00:00

abstract：:The natural abundance 13C NMR intensity of the glycogen C1 resonance was measured in the surgically exposed liver of rabbits in vivo (n = 17) by integration from 98 to 104 ppm and compared double blindedly to the subsequent biochemical measurement. Coil loading was measured each time from a reference sphere at the coi...

journal_title：Magnetic resonance in medicine

authors： Gruetter R,Magnusson I,Rothman DL,Avison MJ,Shulman RG,Shulman GI

更新日期：1994-06-01 00:00:00

abstract：PURPOSE:MR fingerprinting (MRF) is a technique for quantitative tissue mapping using pseudorandom measurements. To estimate tissue properties such as T1 , T2 , proton density, and B0 , the rapidly acquired data are compared against a large dictionary of Bloch simulations. This matching process can be a very computation...

journal_title：Magnetic resonance in medicine

authors： Cauley SF,Setsompop K,Ma D,Jiang Y,Ye H,Adalsteinsson E,Griswold MA,Wald LL

更新日期：2015-08-01 00:00:00

abstract：:High-resolution magic-angle spinning has become a valuable tool to study biologic samples; however, there are only a few high-resolution magic-angle spinning methodologies that have been explored specifically to deal with small semisolid biomaterials such as tissues. Here, we report a novel high-resolution (1)H NMR sp...

journal_title：Magnetic resonance in medicine

authors： Wong A,Aguiar PM,Sakellariou D

更新日期：2010-02-01 00:00:00

abstract：:Diffusion-weighted imaging (DWI) is frequently used to diagnose stroke. However, the origin of the observed reduction in the apparent diffusion coefficient (ADC) in the acute phase following ischemia is not well understood. Although cell swelling is considered to play an important role, it is unclear whether this can ...

journal_title：Magnetic resonance in medicine

authors： van Pul C,Jennekens W,Nicolay K,Kopinga K,Wijn PF

更新日期：2005-02-01 00:00:00

abstract：:We describe a versatile NMR probe that is designed for a variety of in vivo spectroscopic studies on small animals in vertical wide-bore magnets. Replaceable brackets enable the coils to be exchanged readily in order to observe 1H, 13C, 31P, and other nuclei, and to carry out double-resonance experiments. Two solenoid...

journal_title：Magnetic resonance in medicine

authors： Lyon RC,Tschudin RG,Daly PF,Cohen JS

更新日期：1988-01-01 00:00:00

abstract：PURPOSE:We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathi...

journal_title：Magnetic resonance in medicine

authors： Kaushik SS,Robertson SH,Freeman MS,He M,Kelly KT,Roos JE,Rackley CR,Foster WM,McAdams HP,Driehuys B

更新日期：2016-04-01 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：:A method is presented for the detection of quadrupole splitting in tissue, where the spectral line splittings are typically unobservable. The method used is a study of the rate of rotation of the flip angle as a function of radiofrequency (rf) amplitude. Our results with samples of skeletal muscle and cat brain indica...

journal_title：Magnetic resonance in medicine

authors： Joseph PM,Summers RM

更新日期：1987-01-01 00:00:00

abstract：:The changes in the response of skeletal muscle to maximal dynamic exercise were investigated in going from a fasted state to a refed state by means of 31P NMR spectroscopy. It was found that in the fasted state, exercise-induced changes in Pi/PCr and in pH were both inhibited, in comparison with those in the refed sta...

journal_title：Magnetic resonance in medicine

authors： Lunt JA,Allen PS,Brauer M,Swinamer D,Treiber EO,Belcastro A,Eccles R,King EG

更新日期：1986-12-01 00:00:00

abstract：:Measurements of the volume magnetic susceptibility of solids using the classical Gouy balance approach are hampered by variations in apparent density of the packed powder. In this paper a quantitative NMR measurement of the volume magnetic susceptibility of powdered solids is described and the volume susceptibility of...

journal_title：Magnetic resonance in medicine

authors： Hopkins JA,Wehrli FW

更新日期：1997-04-01 00:00:00

abstract：:Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra-high-field MR. Transmit coil arrays enable such techniques as B(1) (+) shimming to substantially improve transmit B(1) homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imagin...

journal_title：Magnetic resonance in medicine

authors： Adriany G,Auerbach EJ,Snyder CJ,Gözübüyük A,Moeller S,Ritter J,Van de Moortele PF,Vaughan T,Uğurbil K

更新日期：2010-06-01 00:00:00

abstract：:Susceptibility artifacts and transmission radio frequency (RF) field (B(1) +) inhomogeneity are major limitations in high-field gradient echo MRI. Previously proposed numerical 2D spectral-spatial RF pulses have been shown to be promising for reducing the through-plane signal loss susceptibility artifact by incorporat...

journal_title：Magnetic resonance in medicine

authors： Yang C,Deng W,Stenger VA

更新日期：2011-02-01 00:00:00

abstract：PURPOSE:To model and correct the dephasing effects in the gradient-echo signal for arbitrary RF excitation pulses with large flip angles in the presence of macroscopic field variations. METHODS:The dephasing of the spoiled 2D gradient-echo signal was modeled using a numerical solution of the Bloch equations to calcula...

journal_title：Magnetic resonance in medicine

authors： Soellradl M,Lesch A,Strasser J,Pirpamer L,Stollberger R,Ropele S,Langkammer C

更新日期：2020-08-01 00:00:00

abstract：:Vascular-space-occupancy (VASO) MRI exploits the difference between blood and tissue T1 to null blood signal and measure cerebral blood volume changes using the residual tissue signal. VASO imaging is more difficult at higher field because of sensitivity loss due to the convergence of tissue and blood T1 values and in...

journal_title：Magnetic resonance in medicine

authors： Hua J,Jones CK,Qin Q,van Zijl PC

更新日期：2013-04-01 00:00:00

abstract：:Developing a method to noninvasively monitor tissue-engineered constructs is critical for the optimization of construct design and for assessing therapeutic efficacy. For this purpose, NMR is a powerful technique that can be used to obtain both images and spectroscopic data. But the inherent sensitivity of NMR limits ...

journal_title：Magnetic resonance in medicine

authors： Volland NA,Mareci TH,Constantinidis I,Simpson NE

更新日期：2010-04-01 00:00:00

abstract：:An eight-channel receive-only brain coil and table-top detunable volume transmit coil were developed and tested at 7 T for human imaging. Optimization of this device required attention to sources of interaction between the array elements, between the transmit and receive coils and minimization of common mode currents ...

journal_title：Magnetic resonance in medicine

authors： Wiggins GC,Potthast A,Triantafyllou C,Wiggins CJ,Wald LL

更新日期：2005-07-01 00:00:00

abstract：:Phase-contrast magnetic resonance imaging is subject to numerous sources of error, which decrease clinical confidence in the reported measures. This work outlines how stationary perivascular fat can impart a significant chemical shift induced phase-contrast magnetic resonance imaging measurement error using computatio...

journal_title：Magnetic resonance in medicine

authors： Middione MJ,Ennis DB

更新日期：2013-02-01 00:00:00

abstract：:Phosphorus NMR can measure myocardial tissue pH from the chemical shift of inorganic phosphate (Pi) in isolated buffer-perfused hearts, but in vivo the Pi peak originating from the myocardium is obscured by the resonance of 2,3-diphosphoglycerate (DPG) in the blood, making pH difficult to determine. Taking advantage o...

journal_title：Magnetic resonance in medicine

authors： Zahler R,Majumdar S,Frederick B,Laughlin M,Barrett E,Gore JC

更新日期：1991-02-01 00:00:00