Polymer thick film technology for improved simultaneous dEEG/MRI recording: Safety and MRI data quality.

abstract：PURPOSE:To accelerate the acquisition of J-resolved proton magnetic resonance spectroscopic imaging (1 H-MRSI) data for high-resolution mapping of brain metabolites and neurotransmitters. METHODS:The proposed method used a subspace model to represent multidimensional spatiospectral functions, which significantly reduc...

journal_title：Magnetic resonance in medicine

authors： Tang L,Zhao Y,Li Y,Guo R,Clifford B,El Fakhri G,Ma C,Liang ZP,Luo J

更新日期：2021-01-01 00:00:00

abstract：:Pattern recognition techniques (factor analysis and neural networks) were used to investigate and classify human brain tumors based on the 1H NMR spectra of chemically extracted biopsies (n = 118). After removing information from lactate (because of variable ischemia times), unsupervised learning suggested that the sp...

journal_title：Magnetic resonance in medicine

authors： Maxwell RJ,Martínez-Pérez I,Cerdán S,Cabañas ME,Arús C,Moreno A,Capdevila A,Ferrer E,Bartomeus F,Aparicio A,Conesa G,Roda JM,Carceller F,Pascual JM,Howells SL,Mazucco R,Griffiths JR

更新日期：1998-06-01 00:00:00

abstract：:Short image acquisition times and sensitivity to magnetic susceptibility favor the use of gradient echo imaging methods in functional MRI (fMRI). However, magnetic susceptibility effects attributed to air-tissue interfaces also lead to severe signal loss in images of the large inferior frontal and lateral temporal cor...

journal_title：Magnetic resonance in medicine

authors： Yang QX,Dardzinski BJ,Li S,Eslinger PJ,Smith MB

更新日期：1997-03-01 00:00:00

abstract：PURPOSE:Phosphomono- and diesters, the major components of the choline peak in (1) H magnetic resonance spectroscopy, are associated with membrane anabolic and catabolic mechanisms. With the refocused insensitive nuclei-enhanced polarization transfer technique, these phospholipids are edited and enhanced in the (31) P ...

journal_title：Magnetic resonance in medicine

authors： Biedermann SV,Weber-Fahr W,Demirakca T,Tunc-Skarka N,Hoerst M,Henn F,Sartorius A,Ende G

更新日期：2015-04-01 00:00:00

abstract：PURPOSE:The goal of this study is to characterize and improve the accuracy of 2D magnetic resonance fingerprinting (MRF) scans in the presence of slice profile (SP) and B1 imperfections, which are two main factors that affect quantitative results in MRF. METHODS:The SP and B1 imperfections are characterized and correc...

journal_title：Magnetic resonance in medicine

authors： Ma D,Coppo S,Chen Y,McGivney DF,Jiang Y,Pahwa S,Gulani V,Griswold MA

更新日期：2017-11-01 00:00:00

abstract：PURPOSE:Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase ...

journal_title：Magnetic resonance in medicine

authors： Cui SX,Epstein FH

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:To develop a fully automated trajectory and gradient waveform design for the non-Cartesian shells acquisition, and to develop a magnetization-prepared (MP) shells acquisition to achieve an efficient three-dimensional acquisition with improved gray-to-white brain matter contrast. METHODS:After reviewing the she...

journal_title：Magnetic resonance in medicine

authors： Shu Y,Tao S,Trzasko JD,Huston J 3rd,Weavers PT,Bernstein MA

更新日期：2018-04-01 00:00:00

abstract：:Metallic implants, such as stents, have long been a concern in magnetic resonance imaging (MRI). In addition to safety issues, they are commonly associated with image artifacts. The mechanisms of radiofrequency- (RF) and susceptibility-induced artifacts have been thoroughly investigated. However, gradient-switching-in...

journal_title：Magnetic resonance in medicine

authors： Shenhav A,Azhari H

更新日期：2004-12-01 00:00:00

abstract：:Gliomas are the most common primary brain tumors and the majority are highly malignant, with one of the worst prognoses for patients. Gliomas are characterized by invasive growth into normal brain tissue that makes complete surgical resection and accurate radiotherapy planning extremely difficult. We have performed in...

journal_title：Magnetic resonance in medicine

authors： Wright AJ,Fellows G,Byrnes TJ,Opstad KS,McIntyre DJ,Griffiths JR,Bell BA,Clark CA,Barrick TR,Howe FA

更新日期：2009-12-01 00:00:00

abstract：:A modified inversion-recovery sequence is introduced which performs subtraction angiography by varying time-of-flight effects of blood flowing into an imaged slab. The selective 180 degrees excitation inverts different regions between measurements to isolate arterial and/or venous blood. On normal human subjects, high...

journal_title：Magnetic resonance in medicine

authors： Nishimura DG,Macovski A,Pauly JM,Conolly SM

更新日期：1987-02-01 00:00:00

abstract：:Myocardial MR first-pass perfusion time courses are contaminated by signals from the ventricles (spillover) as a consequence of partial volume effects and motion. An early increase in the signal intensity from the myocardium is an indicator of contamination. This contamination leads to under- or overestimation of perf...

journal_title：Magnetic resonance in medicine

authors： Köstler H,Ritter C,Reiss-Zimmermann M,Beer M,Hahn D,Sandstede J

更新日期：2004-04-01 00:00:00

abstract：:Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...

journal_title：Magnetic resonance in medicine

authors： Lin W,Paczynski RP,Celik A,Hsu CY,Powers WJ

更新日期：1998-12-01 00:00:00

abstract：:A technique for reconstructing dynamic undersampled MRI data, termed "x-f choice," was developed and applied to dynamic contrast-enhanced MR angiography (DCE-MRA). Regular undersampling in k-t space (a hybrid of k-space and time) creates aliasing in the conjugate x-f space that must be resolved. When regions in the ob...

journal_title：Magnetic resonance in medicine

authors： Malik SJ,Schmitz S,O'Regan D,Larkman DJ,Hajnal JV

更新日期：2006-10-01 00:00:00

abstract：PURPOSE:To present the results of the first human spinal cord in vivo MRI scans at 9.4T. METHODS:A human brain coil was used to image the human spinal cord at 9.4T. All anatomical images were acquired with a T2 *-weighted gradient-echo sequence. A comparison of the influence of four different B0 shimming routines on t...

journal_title：Magnetic resonance in medicine

authors： Geldschläger O,Bosch D,Avdievich NI,Henning A

更新日期：2021-02-01 00:00:00

abstract：:TOMROP is a multiple readout single inversion-recovery sequence which may potentially allow the measurement of multi-exponential T1 recoveries in vivo by NMR imaging. It is shown that several important modifications must be made to this sequence to permit T1 to be measured accurately and reliably. With these modificat...

journal_title：Magnetic resonance in medicine

authors： Gowland PA,Leach MO

更新日期：1992-07-01 00:00:00

abstract：:A pulse sequence is presented for obtaining a single image with combined T1/T2 weighting. T2 relaxation is made to increase intensity, in cooperation with the effect of T1 relaxation, by providing T2 weighting with a 90 degrees-180 degrees-90 degrees driven inversion pulse triplet in an inversion recovery method. Unli...

journal_title：Magnetic resonance in medicine

authors： Conturo TE,Kessler RM,Beth AH

更新日期：1990-09-01 00:00:00

abstract：:MnCl(2) was injected intrathecally through the cisterna magna in rats, allowing infusion of divalent manganese ions (Mn(++)) into the CSF space and thence into the brain, without breaking the blood-brain barrier (BBB). Mn(++) uptake and washout dynamics in the brain were measured by serial T(1)-weighted MRI and EPI T(...

journal_title：Magnetic resonance in medicine

authors： Liu CH,D'Arceuil HE,de Crespigny AJ

更新日期：2004-05-01 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：:The harmonic phase (HARP) method provides automatic and rapid analysis of tagged magnetic resonance (MR) images for quantification and visualization of myocardial strain. In this article, the development and implementation of a pulse sequence that acquires HARP images in real time are described. In this pulse sequence...

journal_title：Magnetic resonance in medicine

authors： Sampath S,Derbyshire JA,Atalar E,Osman NF,Prince JL

更新日期：2003-07-01 00:00:00

abstract：:A new approach to autocalibrating, coil-by-coil parallel imaging reconstruction, is presented. It is a generalized reconstruction framework based on self-consistency. The reconstruction problem is formulated as an optimization that yields the most consistent solution with the calibration and acquisition data. The appr...

journal_title：Magnetic resonance in medicine

authors： Lustig M,Pauly JM

更新日期：2010-08-01 00:00:00

abstract：PURPOSE:To improve quantification of myocardial blood flow using a fast T1 mapping technique using highly constrained back projection reconstruction (HYPR)-accelerated acquisition. METHODS:A major source of error in the measurement of myocardial blood flow (MBF) using MRI is the nonlinear relationship between image si...

journal_title：Magnetic resonance in medicine

authors： Chen D,Sharif B,Dharmakumar R,Thomson LE,Bairey Merz CN,Berman DS,Li D

更新日期：2014-09-01 00:00:00

abstract：PURPOSE:To characterize the fundamental limits of MRI near metallic implants on RF excitation, frequency encoding, and chemical shift-encoding water-fat separation. METHODS:Multicomponent three-dimensional (3D) digital models of a total hip and a total knee replacement were used to construct material-specific suscepti...

journal_title：Magnetic resonance in medicine

authors： Smith MR,Artz NS,Wiens C,Hernando D,Reeder SB

更新日期：2015-12-01 00:00:00

abstract：:In radiotherapy, target tissues are defined best on MR images due to their superior soft tissue contrast. Computed tomography imaging is geometrically accurate and it is needed for dose calculation and generation of reference images for treatment localization. Co-registration errors between MR and computed tomography ...

journal_title：Magnetic resonance in medicine

authors： Kapanen M,Collan J,Beule A,Seppälä T,Saarilahti K,Tenhunen M

更新日期：2013-07-01 00:00:00

abstract：PURPOSE:Recent literature shows that diffusion tensor properties can be estimated more accurately with diffusion kurtosis imaging (DKI) than with diffusion tensor imaging (DTI). Furthermore, the additional non-Gaussian diffusion features from DKI can be sensitive markers for tissue characterization. Despite these benef...

journal_title：Magnetic resonance in medicine

authors： Tax CM,Otte WM,Viergever MA,Dijkhuizen RM,Leemans A

更新日期：2015-02-01 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：:Formalin fixation of tissue is a common laboratory practice. A direct comparison of diffusion tensor imaging (DTI) parameters from mouse brains before (in vivo) and after (ex vivo) formalin fixation is reported herein. Five diffusion indices were examined in a cohort of seven mice: relative anisotropy (RA), directiona...

journal_title：Magnetic resonance in medicine

authors： Sun SW,Neil JJ,Song SK

更新日期：2003-10-01 00:00:00

abstract：:At high magnetic fields the performance of a volume-type body coil inside a human sized MR-scanner is influenced by the waveguide action of the scanner's bore. This can result in undesirable strong radio frequency fields B1+) outside the coil's target volume. A radio frequency (RF) transmit system, exploiting this wav...

journal_title：Magnetic resonance in medicine

authors： Andreychenko A,Kroeze H,Klomp DW,Lagendijk JJ,Luijten PR,van den Berg CA

更新日期：2013-09-01 00:00:00

abstract：:The dependence of 1/T1 on the magnetic field strength (the relaxation dispersion) has been measured at 37 degrees C on autopsy samples of human brain gray and white matter at field strengths corresponding to proton Larmor frequencies between 10 kHz and 50 MHz (0.0002-1.2 T). Additional measurements of 1/T1 and 1/T2 ha...

journal_title：Magnetic resonance in medicine

authors： Fischer HW,Rinck PA,Van Haverbeke Y,Muller RN

更新日期：1990-11-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 00:00:00

abstract：:This work helps elucidate how background noise introduces statistical artifacts in the distribution of the sorted eigenvalues and eigenvectors in diffusion tensor MRI (DT-MRI) data. Although it was known that sorting eigenvalues (principal diffusivities) by magnitude introduces a bias in their sample mean within a hom...

journal_title：Magnetic resonance in medicine

authors： Basser PJ,Pajevic S

更新日期：2000-07-01 00:00:00