Work-related factors associated with occupational exposure to static magnetic stray fields from MRI scanners.

abstract：:IVIM MR imaging is a method which generates images of diffusion and perfusion in vivo. Until now, intravoxel incoherent motion (IVIM) images have been obtained using spin-echo sequences with extragradient pulses, resulting in long acquisition times (typically 2 x 8 min 32 s). A new method is proposed here, using stead...

journal_title：Magnetic resonance in medicine

authors： Le Bihan D

更新日期：1988-07-01 00:00:00

abstract：:The somatotopical organization of the human somatosensory cortex was analyzed with echo-planar imaging at 1.5 Tesla, utilizing deoxyhemoglobin as an endogenous contrast medium. Scrubbing stimulation at a frequency of 3 Hz was applied to one of three cutaneous areas: toes, fingertips, and tongue tip. Parasagittal echo-...

journal_title：Magnetic resonance in medicine

authors： Sakai K,Watanabe E,Onodera Y,Itagaki H,Yamamoto E,Koizumi H,Miyashita Y

更新日期：1995-05-01 00:00:00

abstract：:In order to determine if an increase in myocardial oxygen consumption is accompanied by changes in high energy phosphates in normal subjects and patients with dilated cardiomyopathy, phosphorus-31 spectra were acquired under resting conditions and during dobutamine infusion. In seven normal subjects, dobutamine raised...

journal_title：Magnetic resonance in medicine

authors： Schaefer S,Schwartz GG,Steinman SK,Meyerhoff DJ,Massie BM,Weiner MW

更新日期：1992-06-01 00:00:00

abstract：:The reconstruction of non-Cartesian k-space trajectories often requires the estimation of nonuniform sampling density. Particularly for 3D, this calculation can be computationally expensive. The method proposed in this work combines an iterative algorithm previously proposed by Pipe and Menon (Magn Reson Med 1999;41:1...

journal_title：Magnetic resonance in medicine

authors： Zwart NR,Johnson KO,Pipe JG

更新日期：2012-03-01 00:00:00

abstract：:It is shown that the effect of pH changes can be measured in proton NMR spectra through the pH sensitivity of the signal intensities of metabolite protons exchanging with water. To observe this phenomenon, pulse sequences must be used that can sensitively observe these exchangeable protons under physiological conditio...

journal_title：Magnetic resonance in medicine

authors： Mori S,Eleff SM,Pilatus U,Mori N,van Zijl PC

更新日期：1998-07-01 00:00:00

abstract：:The apparent diffusion coefficient (ADC) in the optic nerve was measured from diffusion-weighted magnetic resonance imaging using an intravoxel incoherent motion (IVIM) sequence. The subjects were seven normal volunteers and eight patients with multiple sclerosis (MS) with a total of four optic nerves with acute neuri...

journal_title：Magnetic resonance in medicine

authors： Iwasawa T,Matoba H,Ogi A,Kurihara H,Saito K,Yoshida T,Matsubara S,Nozaki A

更新日期：1997-09-01 00:00:00

abstract：:The idea of using parallel imaging to shorten the acquisition time by the simultaneous use of multiple receive coils can be adapted for the parallel transmission of a spatially-selective multidimensional RF pulse. As in data acquisition, a multidimensional RF pulse follows a certain k-space trajectory. Shortening this...

journal_title：Magnetic resonance in medicine

authors： Katscher U,Börnert P,Leussler C,van den Brink JS

更新日期：2003-01-01 00:00:00

abstract：:Coronal proton and sodium images of control rats and rats with either increased permeability edema produced by intravenous alloxan (300 mg/kg) or increased pressure edema produced by saline infusion (2 ml/min) were obtained. Axial chest CT images were used to monitor the development of pulmonary edema. Immediately aft...

journal_title：Magnetic resonance in medicine

authors： Kundel HL,Shetty A,Joseph PM,Summers RM,Kassab EA,Moore B

更新日期：1988-04-01 00:00:00

abstract：:The signals of water in the different compartments of rat sciatic nerve are resolved in the (2)H double-quantum-filtered NMR spectrum, due to their different quadrupolar splittings and relaxation rates. This resolution allowed the independent measurement of the water diffusion coefficients in the different compartment...

journal_title：Magnetic resonance in medicine

authors： Seo Y,Shinar H,Morita Y,Navon G

更新日期：1999-09-01 00:00:00

abstract：:We applied MRI to the in vivo detection of spontaneous colorectal tumors in a unique mouse model, the Fox Chase Cancer Center (FCCC) ApcMIN mouse. Unlike other Min (multiple intestinal neoplasia) strains, FCCC ApcMIN animals develop an appreciable number of tumors in the large intestine, which makes them an appropriat...

journal_title：Magnetic resonance in medicine

authors： Hensley HH,Chang WC,Clapper ML

更新日期：2004-09-01 00:00:00

abstract：:A new decoupling sequence, PBAR, is described for broadband heteronuclear decoupling in vivo in humans at 1.5T. The sequence uses non-adiabatic, frequency- and amplitude-modulated inversion pulses designed to minimize decoupling sidebands at low applied gammaB(2) RF field levels and to cover only the narrow range of r...

journal_title：Magnetic resonance in medicine

authors： Barker PB,Golay X,Artemov D,Ouwerkerk R,Smith MA,Shaka AJ

更新日期：2001-02-01 00:00:00

abstract：:The concept of temporal echo multiplexing is defined and used to develop rapid biphasic spin-echo sequences for imaging the heart. Three imaging sequences, based on four-echo and two-echo multiplexing and rapid single echo (i.e., conventional spin-echo imaging), are compared. Preliminary results indicate that two-echo...

journal_title：Magnetic resonance in medicine

authors： Parker DL,Caputo GR,Frederick PR

更新日期：1989-07-01 00:00:00

abstract：PURPOSE:MRI can produce quantitative liver fat fraction (FF) maps noninvasively, which can help to improve diagnoses of fatty liver diseases. However, most sequences acquire several two-dimensional (2D) slices during one or more breath-holds, which may be difficult for patients with limited breath-holding capacity. A w...

journal_title：Magnetic resonance in medicine

authors： Arboleda C,Aguirre-Reyes D,García MP,Tejos C,Muñoz L,Miquel JF,Irarrazaval P,Andia ME,Uribe S

更新日期：2016-11-01 00:00:00

abstract：PURPOSE:Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine data...

journal_title：Magnetic resonance in medicine

authors： Odille F,Bustin A,Liu S,Chen B,Vuissoz PA,Felblinger J,Bonnemains L

更新日期：2018-05-01 00:00:00

abstract：PURPOSE:In this work, 22 configurations for remote radiofrequency (RF) coil arrays consisting of different transmit element designs for 7 Tesla (T) ultrahigh-field MRI are compared by numerical simulations. METHODS:Investigated transmit RF element types are rectangular loops, micro striplines, micro striplines with me...

journal_title：Magnetic resonance in medicine

authors： Rietsch SHG,Orzada S,Bitz AK,Gratz M,Ladd ME,Quick HH

更新日期：2018-02-01 00:00:00

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：:TSENSE and TGRAPPA are autocalibrated parallel imaging techniques that can improve the temporal resolution and/or spatial resolution in dynamic magnetic resonance imaging applications. In its original form, TSENSE uses temporal low-pass filtering of the undersampled frames to create the sensitivity map. TGRAPPA uses a...

journal_title：Magnetic resonance in medicine

authors： Ding Y,Chung YC,Jekic M,Simonetti OP

更新日期：2011-06-01 00:00:00

abstract：PURPOSE:We describe a 2 × 6 channel sodium/proton array for knee MRI at 3T. Multielement coil arrays are desirable because of well-known signal-to-noise ratio advantages over volume and single-element coils. However, low tissue-coil coupling that is characteristic of coils operating at low frequency can make the potent...

journal_title：Magnetic resonance in medicine

authors： Brown R,Lakshmanan K,Madelin G,Alon L,Chang G,Sodickson DK,Regatte RR,Wiggins GC

更新日期：2016-10-01 00:00:00

abstract：:MRI evaluations of intramyocardial hemorrhage in acute infarction have relied on T(2) and T(2)(*) shortening only. We propose a more comprehensive evaluation of hemorrhagic infarction based on the concept that fluctuations in T(2) and T(1) relaxation in acute reperfused infarction will reflect transient edema and hemo...

journal_title：Magnetic resonance in medicine

authors： Foltz WD,Yang Y,Graham JJ,Detsky JS,Wright GA,Dick AJ

更新日期：2006-12-01 00:00:00

abstract：PURPOSE:Banding artifacts in images acquired by balanced steady-state free precession (bSSFP) remain a challenge in MRI as they considerably reduce image quality, and diagnostic value deteriorates accordingly. As the steady-state tolerates small shifts in frequency, it is possible to acquire frequency-modulated bSSFP. ...

journal_title：Magnetic resonance in medicine

authors： Slawig A,Wech T,Ratz V,Tran-Gia J,Neubauer H,Bley T,Köstler H

更新日期：2017-12-01 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 relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

journal_title：Magnetic resonance in medicine

authors： Zheng S,Xia Y

更新日期：2010-01-01 00:00:00

abstract：:Golgi impregnation is unique in its ability to display the dendritic trees and axons of large numbers of individual neurons by histology. Here we apply magnetic resonance microscopy to visualize the neuroanatomy of animal models by combining histologic fixation chemistry with paramagnetic contrast agents. Although the...

journal_title：Magnetic resonance in medicine

authors： Zhang X,Bearer EL,Perles-Barbacaru AT,Jacobs RE

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:To characterize the q-space truncation and sampling on the spin-displacement probability density function (PDF) in diffusion spectrum imaging (DSI). METHODS:DSI data were acquired using the MGH-USC connectome scanner (Gmax  = 300 mT/m) with bmax  = 30,000 s/mm2 , 17 × 17 × 17, 15 × 15 × 15 and 11 × 11 × 11 gri...

journal_title：Magnetic resonance in medicine

authors： Tian Q,Rokem A,Folkerth RD,Nummenmaa A,Fan Q,Edlow BL,McNab JA

更新日期：2016-12-01 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：PURPOSE:To develop the simultaneous acquisition of multiple voxels in localized MR spectroscopy (MRS) using sensitivity encoding, allowing reduced total scan time compared to conventional sequential single voxel (SV) acquisition methods. METHODS:Dual volume localization was used to simultaneously excite voxels in both...

journal_title：Magnetic resonance in medicine

authors： Boer VO,Klomp DW,Laterra J,Barker PB

更新日期：2015-09-01 00:00:00

abstract：PURPOSE:We report a series of techniques to reliably eliminate artifacts in interleaved echo-planar imaging (EPI) based diffusion-weighted imaging (DWI). METHODS:First, we integrate the previously reported multiplexed sensitivity encoding (MUSE) algorithm with a new adaptive Homodyne partial-Fourier reconstruction alg...

journal_title：Magnetic resonance in medicine

authors： Chang HC,Guhaniyogi S,Chen NK

更新日期：2015-05-01 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：:Chemically-fixed nervous tissues are well-suited for high-resolution, time-intensive MRI acquisitions without motion artifacts, such as those required for brain atlas projects, but the aldehyde fixatives used may significantly alter tissue MRI properties. To test this hypothesis, this study characterized the impact of...

journal_title：Magnetic resonance in medicine

authors： Shepherd TM,Thelwall PE,Stanisz GJ,Blackband SJ

更新日期：2009-07-01 00:00:00

abstract：PURPOSE:For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, w...

journal_title：Magnetic resonance in medicine

authors： Ahmad R,Xue H,Giri S,Ding Y,Craft J,Simonetti OP

更新日期：2015-11-01 00:00:00