Detection of liver fibrosis with magnetic cross-relaxation.

abstract：:The accurate assessment of pulmonary perfusion is especially important in the evaluation of patients with suspected pulmonary embolism, a common and potentially lethal disorder that can be treated by aggressive anticoagulation. In this study, we demonstrate for the first time the use of MR to image pulmonary perfusion...

journal_title：Magnetic resonance in medicine

authors： Hatabu H,Gaa J,Kim D,Li W,Prasad PV,Edelman RR

更新日期：1996-10-01 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：PURPOSE:To explore the effects of high permittivity dielectric pads on the transmit and receive characteristics of a 3 Tesla body coil centered at the thighs, and their implications on image uniformity in receive array applications. THEORY AND METHODS:Transmit and receive profiles of the body coil with and without die...

journal_title：Magnetic resonance in medicine

authors： Brink WM,Versluis MJ,Peeters JM,Börnert P,Webb AG

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS:Mapping a signa...

journal_title：Magnetic resonance in medicine

authors： Holbrook AB,Ghanouni P,Santos JM,Dumoulin C,Medan Y,Pauly KB

更新日期：2014-02-01 00:00:00

abstract：PURPOSE:To systematically evaluate the dependence of intravoxel-incoherent-motion (IVIM) parameters on the b-value threshold separating the perfusion and diffusion compartment, and to implement and test an algorithm for the standardized computation of this threshold. METHODS:Diffusion weighted images of the upper abdo...

journal_title：Magnetic resonance in medicine

authors： Wurnig MC,Donati OF,Ulbrich E,Filli L,Kenkel D,Thoeny HC,Boss A

更新日期：2015-11-01 00:00:00

abstract：:We improved the three-point phase-contrast method by regularization of MR velocity data after acquisition of a low velocity-to-noise ratio (VNR) velocity image and a high VNR aliased velocity image. The phase unwrapping algorithm is based on the assumed correlation of the velocity of adjacent flow voxels on the low VN...

journal_title：Magnetic resonance in medicine

authors： Herment A,Mousseaux E,Jolivet O,DeCesare A,Frouin F,Todd-Pokropek A,Bittoun J

更新日期：2000-07-01 00:00:00

abstract：:A method for volume selective proton spectroscopy is presented based on a multiecho sequence with short refocusing interval tcp. It is demonstrated, that by appropriate choice of tcp on the order of 4-6 ms, signals from overlapping multiplets like the glutamine and glutamate (Glu/Gln) resonances in spectra of the huma...

journal_title：Magnetic resonance in medicine

authors： Hennig J,Thiel T,Speck O

更新日期：1997-06-01 00:00:00

abstract：:A new k-space direct matrix inversion (DMI) method is proposed here to accelerate non-Cartesian SENSE reconstructions. In this method a global k-space matrix equation is established on basic MRI principles, and the inverse of the global encoding matrix is found from a set of local matrix equations by taking advantage ...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Zhang Z,Wang Y,Boada FE

更新日期：2006-08-01 00:00:00

abstract：:An in vitro study was performed to investigate the effects of B(o) inhomogeneity on magnetic resonance images of flow. Controlled inhomogeneity gradients (Gi) were applied and the magnitude of the artifacts produced was quantified for different echo delay times (TE). Both steady and pulsatile flows were examined. In t...

journal_title：Magnetic resonance in medicine

authors： Drangova M,Pelc NJ

更新日期：1996-01-01 00:00:00

abstract：PURPOSE:To significantly reduce the background phase effects, especially at the air-tissue interface, and to enhance the desirable local structures of veins in susceptibility-weighted imaging. METHODS:In the proposed reconstruction method called Magnitude of Complex Filtering, a complex-valued magnetic resonance image...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Han Y,Park H

更新日期：2014-03-01 00:00:00

abstract：:Two different types of (co-registered) images of the same slice of tissue will generally have different spatial resolutions. The judicious pixel-by-pixel combination of their data can be accomplished to yield a single image exhibiting properties of both. Here, axial (18)FDG PET and (1)H(2)O MR images of the human brai...

journal_title：Magnetic resonance in medicine

authors： Sammi MK,Felder CA,Fowler JS,Lee JH,Levy AV,Li X,Logan J,Pályka I,Rooney WD,Volkow ND,Wang GJ,Springer CS Jr

更新日期：1999-08-01 00:00:00

abstract：:A method for calculating quantitative three-dimensional susceptibility maps from field measurements acquired using gradient echo imaging at high field is presented. This method is based on division of the three-dimensional Fourier transforms of high-pass-filtered field maps by a simple function that is the Fourier tra...

journal_title：Magnetic resonance in medicine

authors： Wharton S,Schäfer A,Bowtell R

更新日期：2010-05-01 00:00:00

abstract：:The ultra-fast application of the RARE experiment is described in detail, with special emphasis on its multifarious applications with preparation experiments that produce transverse magnetization. The factors affecting the temporal evolution of the magnetization during the experiment are described, and the implication...

journal_title：Magnetic resonance in medicine

authors： Norris DG,Börnert P,Reese T,Leibfritz D

更新日期：1992-09-01 00:00:00

abstract：:Spiral k-space magnetic resonance spectroscopic imaging (MRSI) requires high performance from gradient hardware systems. During the readout phase, oscillating gradients are continuously played out, which can cause undesired effects. These effects on the quality of SI data are non-intuitive because of their time-varyin...

journal_title：Magnetic resonance in medicine

authors： Kim DH,Spielman DM

更新日期：2006-07-01 00:00:00

abstract：:We developed a quantitative magnetic resonance imaging method to permit a rapid assessment of brain water content during osmotic brain edema produced by intraperitoneal (ip) injection of distilled water. Fifteen minutes after water injection, the normalized mean image intensity (MIn) from a spin-echo pulse sequence (T...

journal_title：Magnetic resonance in medicine

authors： Olson JE,Katz-Stein A,Reo NV,Jolesz FA

更新日期：1992-03-01 00:00:00

abstract：:The theoretical description of steady state free precession (SSFP) sequences is generally well accepted and unquestioned, although it is based on instantaneously acting radiofrequency (RF) pulses. In practice, however, all excitation processes are finite, thereby questioning the overall validity of the common SSFP sig...

journal_title：Magnetic resonance in medicine

authors： Bieri O,Scheffler K

更新日期：2009-11-01 00:00:00

abstract：:Activity-induced manganese-dependent contrast (AIM) MRI is a hemodynamic-independent functional MRI method that used manganese ion as an MR-detectable contrast agent. In AIM, MnCl(2) is infused intra-arterially after the blood-brain barrier (BBB) is opened with a hyperosmolar agent. Upon functional stimulation of the ...

journal_title：Magnetic resonance in medicine

authors： Aoki I,Tanaka C,Takegami T,Ebisu T,Umeda M,Fukunaga M,Fukuda K,Silva AC,Koretsky AP,Naruse S

更新日期：2002-12-01 00:00:00

abstract：:This study investigated the use of peritoneal dialysis fluid (dialyzate) as a MR contrast agent to visualize the liver structure and peritoneal adhesion in rats at 7 T. Intraperitoneal injection of dialyzate (approximately 0.1 ml/g) yielded excellent and consistent intraperitoneal enhancement that delineated the liver...

journal_title：Magnetic resonance in medicine

authors： Cheung JS,Guo H,Leung JC,Man K,Lai KN,Wu EX

更新日期：2008-05-01 00:00:00

abstract：:The use of paramagnetic pH-sensitive liposomes was recently suggested as a new approach for monitoring pathologic changes in pH by MRI. Such liposomes must be stable in blood and selectively release the encapsulated paramagnetic agent when exposed to lower pH in the target tissue. In the present study, different lipos...

journal_title：Magnetic resonance in medicine

authors： Løkling KE,Skurtveit R,Bjørnerud A,Fossheim SL

更新日期：2004-04-01 00:00:00

abstract：:Fe(III)meso-tetra(4-sulfonatophenyl)porphine (Fe-TPPS4) has been investigated as a potential pH-sensitive nuclear magnetic resonance (NMR) proton image contrast agent. Relaxation rates (1/T1 and 1/T2) of water protons were measured as a function of pH and concentration of Fe-TPPS4 in phosphate-buffered isotonic saline...

journal_title：Magnetic resonance in medicine

authors： Helpern JA,Curtis JC,Hearshen D,Smith MB,Welch KM

更新日期：1987-09-01 00:00:00

abstract：:Cortical spreading depression (CSD) was visualized using manganese-enhanced MRI (MEMRI) following topical application of KCl to the exposed rat cortex. MEMRI signal increase in the ipsilateral cortex relative to the contralateral control region was 60 +/- 30% following two KCl applications. MEMRI signal increase for a...

journal_title：Magnetic resonance in medicine

authors： Henning EC,Meng X,Fisher M,Sotak CH

更新日期：2005-04-01 00:00:00

abstract：:The resolution and homogeneity limitations of echo-planar imaging (EPI) are overcome by zoom imaging of an easily shimmed localized volume. Use of the stimulated echo enables single-shot localization. In vivo 0.5-mm resolution EPI images of selected regions of a cat brain at 4.7 T are presented. ...

journal_title：Magnetic resonance in medicine

authors： Turner R,von Kienlin M,Moonen CT,van Zijl PC

更新日期：1990-05-01 00:00:00

abstract：:A single breath-hold 3D cardiac phase resolved steady-state free precession (SSFP) sequence was developed, allowing 3D visualization of the moving coronary arteries. A 3D stack of spirals was acquired continuously throughout the cardiac cycle, and a sliding window reconstruction was used to achieve high temporal resol...

journal_title：Magnetic resonance in medicine

authors： Kressler B,Spincemaille P,Nguyen TD,Cheng L,Xi Hai Z,Prince MR,Wang Y

更新日期：2007-09-01 00:00:00

abstract：:In spin echo imaging, magnetization is assigned to a location defined by its frequency of rotation. In the presence of a static magnetic field inhomogeneity, however, this location does not correspond to the true location of the magnetization. This paper describes a magnetic resonance imaging technique called phase co...

journal_title：Magnetic resonance in medicine

authors： Kim JK,Plewes DB,Henkelman RM

更新日期：1995-04-01 00:00:00

abstract：PURPOSE:Sensitivity encoding (SENSE) reconstruction of multiband echo planar imaging (EPI) may cause artifacts when simultaneously excited slices require different phase correction to remove the EPI-specific ghost shifted by half of the matrix size (N). We propose a simplified solution of this problem that combines SEN...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Buehrer M,von Deuster C,Seuven A,Pruessmann KP

更新日期：2016-09-01 00:00:00

abstract：:We report the synthesis and characterization of polyvinyl alcohol (PVA) embolic particles modified with a clinically approved magnetic resonance (MR) contrast agent. PVA particles are used during transcatheter arterial embolization (TAE) procedures and this minimally invasive technique is a widely employed treatment f...

journal_title：Magnetic resonance in medicine

authors： Cilliers R,Song Y,Kohlmeir EK,Larson AC,Omary RA,Meade TJ

更新日期：2008-04-01 00:00:00

abstract：:The time evolution of water diffusion, perfusion, T1, and T2 is investigated at high magnetic field (8.5 T) following permanent middle cerebral artery occlusion in the rat. Cerebral blood flow maps were obtained using arterial spin tagging. Although the quantitative perfusion measurements in ischemic tissue still pose...

journal_title：Magnetic resonance in medicine

authors： Calamante F,Lythgoe MF,Pell GS,Thomas DL,King MD,Busza AL,Sotak CH,Williams SR,Ordidge RJ,Gadian DG

更新日期：1999-03-01 00:00:00

abstract：:Parallel transmission has emerged as an efficient means for implementing multidimensional spatially selective radiofrequency excitation pulses. To date, most theoretical and experimental work on parallel transmission radiofrequency (RF) pulse design is based on the small-tip-angle approximation to the Bloch equation. ...

journal_title：Magnetic resonance in medicine

authors： Zheng H,Zhao T,Qian Y,Ibrahim TS,Boada FE

更新日期：2011-09-01 00:00:00

abstract：:This study demonstrates the in vitro displacement and strain of articular cartilage in a cyclically-compressed and intact joint using displacement-encoded imaging with stimulated echoes (DENSE) and fast spin echo (FSE). Deformation and strain fields exhibited complex and heterogeneous patterns. The displacements in th...

journal_title：Magnetic resonance in medicine

authors： Chan DD,Neu CP,Hull ML

更新日期：2009-04-01 00:00:00

abstract：:Balanced steady-state free precession (SSFP) imaging is sensitive to off-resonance effects, which can lead to considerable artifacts during a transient phase following magnetization preparation or steady-state interruption. In addition, nonlinear k-space encoding is required if contrast-relevant k-space regions need t...

journal_title：Magnetic resonance in medicine

authors： Markl M,Leupold J,Bieri O,Scheffler K,Hennig J

更新日期：2005-10-01 00:00:00