Magnetic resonance-guided thermal surgery.

abstract：PURPOSE:To reduce the influence of tidal volume on fractional ventilation (FV) derived by Fourier decomposition (FD). METHODS:Twelve volunteers were examined on a 1.5 Tesla scanner. Spoiled gradient echo imaging of coronal and sagittal slices of the lung were performed. The tidal volume variations between different ac...

journal_title：Magnetic resonance in medicine

authors： Voskrebenzev A,Gutberlet M,Becker L,Wacker F,Vogel-Claussen J

更新日期：2016-11-01 00:00:00

abstract：:Coronary artery data acquisition with steady-state free precession (SSFP) is typically performed in a single frame in mid-diastole with a spectrally selective pulse to suppress epicardial fat signal. Data are acquired while the signal approaches steady state, which may lead to artifacts from the SSFP transient respons...

journal_title：Magnetic resonance in medicine

authors： Park J,Larson AC,Zhang Q,Simonetti O,Li D

更新日期：2005-10-01 00:00:00

abstract：:Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high-field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in...

journal_title：Magnetic resonance in medicine

authors： Mao W,Smith MB,Collins CM

更新日期：2006-10-01 00:00:00

abstract：:The diffusional kurtosis is an indicator for diffusion restrictions in biological tissue. It is observed experimentally that the kurtosis is largest for directions perpendicular to the fiber direction in white matter. The directional dependence of the kurtosis can be described by the diffusion kurtosis tensor. Since t...

journal_title：Magnetic resonance in medicine

authors： Kuder TA,Stieltjes B,Bachert P,Semmler W,Laun FB

更新日期：2012-05-01 00:00:00

abstract：:In the present work, diffusion-weighted (DW)-NMR spectroscopy of glutamate was performed during a (13)C-labeled glucose infusion in monkey brain (six experiments). It is shown that glutamate (13)C labeling occurs significantly faster at higher diffusion weightings-slightly for glutamate in position C4, and more marked...

journal_title：Magnetic resonance in medicine

authors： Valette J,Chaumeil M,Guillermier M,Bloch G,Hantraye P,Lebon V

更新日期：2008-08-01 00:00:00

abstract：:In proton magnetic resonance imaging (MRI) metallic substances lead to magnetic field distortions that often result in signal voids in the adjacent anatomic structures. Thus, metallic objects and superparamagnetic iron oxide (SPIO)-labeled cells appear as hypointense artifacts that obscure the underlying anatomy. The ...

journal_title：Magnetic resonance in medicine

authors： Stuber M,Gilson WD,Schär M,Kedziorek DA,Hofmann LV,Shah S,Vonken EJ,Bulte JW,Kraitchman DL

更新日期：2007-11-01 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:To develop a modular magnetization preparation sequence for combined T2 -preparation and multidimensional outer volume suppression (OVS) for coronary artery imaging. METHODS:A combined T2 -prepared 1D OVS sequence with fat saturation was defined to contain a 90°-60 180°60 composite nonselective tip-down pulse,...

journal_title：Magnetic resonance in medicine

authors： Zeng DY,Baron CA,Malavé MO,Kerr AB,Yang PC,Hu BS,Nishimura DG

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:To improve the quality and speed of electron paramagnetic resonance imaging (EPRI) acquisition by combining a uniform sampling distribution with spinning gradient acquisition. THEORY AND METHODS:A uniform sampling distribution was derived for spinning gradient EPRI acquisition (uniform spinning sampling, USS) ...

journal_title：Magnetic resonance in medicine

authors： Johnson DH,Ahmad R,Liu Y,Chen Z,Samouilov A,Zweier JL

更新日期：2014-02-01 00:00:00

abstract：PURPOSE:To obtain whole-brain high-resolution T2 maps in 2 minutes by combining simultaneous multislice excitation and low-power PINS (power independent of number of slices) refocusing pulses with undersampling and a model-based reconstruction. METHODS:A multi-echo spin-echo sequence was modified to acquire multiple s...

journal_title：Magnetic resonance in medicine

authors： Hilbert T,Schulz J,Marques JP,Thiran JP,Krueger G,Norris DG,Kober T

更新日期：2019-12-01 00:00:00

abstract：:In the pulsed arterial spin labeling (ASL) techniques EPISTAR, PICORE, and FAIR, subtraction of two images in which inflowing blood is first tagged and then not tagged yields a qualitative map of perfusion. An important reason this map is not quantitative is that there is a spatially varying delay in the transit of bl...

journal_title：Magnetic resonance in medicine

authors： Wong EC,Buxton RB,Frank LR

更新日期：1998-05-01 00:00:00

abstract：:Standard MRI cine exams for the study of cardiac function are segmented over several heartbeats and thus require a breath-hold to minimize breathing motion artifacts, which is a current limitation of this approach. The purpose of this study was to develop a method for the measurement and correction of respiratory moti...

journal_title：Magnetic resonance in medicine

authors： Leung AO,Paterson I,Thompson RB

更新日期：2008-09-01 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：:The estrogen receptor (ER) is a major prognostic biomarker of breast cancer, currently determined in surgical specimens by immunohistochemistry. Two new ER-targeted probes, pyridine-tetra-acetate-Gd chelate (PTA-Gd) conjugated either to 17β-estradiol (EPTA-Gd) or to tamoxifen (TPTA-Gd), were explored as contrast agent...

journal_title：Magnetic resonance in medicine

authors： Pais A,Biton IE,Margalit R,Degani H

更新日期：2013-07-01 00:00:00

abstract：:T2-weighted MRI of edema in acute myocardial infarction (MI) provides a means of differentiating acute and chronic MI, and assessing the area at risk of infarction. Conventional T2-weighted imaging of edema uses a turbo spin-echo (TSE) readout with dark-blood preparation. Clinical applications of dark-blood TSE method...

journal_title：Magnetic resonance in medicine

authors： Kellman P,Aletras AH,Mancini C,McVeigh ER,Arai AE

更新日期：2007-05-01 00:00:00

abstract：:This work presents a method applied to the design of short self-shielded gradient coils of cylindrical geometry. The method uses a hybrid technique that combines the simulated annealing and target field methods to optimize the standard stream functions. The optimized stream functions were parameterized using a few deg...

journal_title：Magnetic resonance in medicine

authors： Tomasi D

更新日期：2001-03-01 00:00:00

abstract：:Parallel imaging based on generalized autocalibrating partially parallel acquisitions is widely used in the clinical routine. To date, no detailed analysis has been presented describing the dependence of the image quality on the reconstruction and acquisition parameters such as the number of autocalibration signal (AC...

journal_title：Magnetic resonance in medicine

authors： Bauer S,Markl M,Honal M,Jung BA

更新日期：2011-08-01 00:00:00

abstract：:The commercial synthetic homopolypeptide polyaspartate (average MW = 30,000, approximately 220 monomers) in solution quantitatively binds up to 40 mol Gd3+ ions per mole of polyaspartate. The water proton relaxivity of the solutions is far higher than that of clinically used or commonly investigated gadolinium(III) co...

journal_title：Magnetic resonance in medicine

authors： Cavagna F,Luchinat C,Scozzafava A,Xia Z

更新日期：1994-01-01 00:00:00

abstract：PURPOSE:A MR thermometry (MRT) method with field monitoring is proposed to improve the measurement of small temperature variations induced in brain MRI exams. METHODS:MR thermometry experiments were performed at 7 Tesla with concurrent field monitoring and RF heating. Images were reconstructed with nominal k-space tra...

journal_title：Magnetic resonance in medicine

authors： Le Ster C,Mauconduit F,Mirkes C,Bottlaender M,Boumezbeur F,Djemai B,Vignaud A,Boulant N

更新日期：2021-03-01 00:00:00

abstract：:A methodology is presented for estimating T(1) using a two-point technique with a standard multislice gradient echo sequence. The method explicitly corrects for the shape of the RF pulse and for spatial variations in transmitted RF field intensity. Including these factors in the calculation of T(1) gives a substantial...

journal_title：Magnetic resonance in medicine

authors： Parker GJ,Barker GJ,Tofts PS

更新日期：2001-05-01 00:00:00

abstract：PURPOSE:Dipole antennas in ultrahigh field MRI have demonstrated advantages over more conventional designs. In this study, the fractionated dipole antenna is presented: a dipole where the legs are split into segments that are interconnected by capacitors or inductors. METHODS:A parameter study has been performed on di...

journal_title：Magnetic resonance in medicine

authors： Raaijmakers AJ,Italiaander M,Voogt IJ,Luijten PR,Hoogduin JM,Klomp DW,van den Berg CA

更新日期：2016-03-01 00:00:00

abstract：:Stejskal and Tanner's ingenious pulsed field gradient design from 1965 has made diffusion NMR and MRI the mainstay of most studies seeking to resolve microstructural information in porous systems in general and biological systems in particular. Methods extending beyond Stejskal and Tanner's design, such as double diff...

journal_title：Magnetic resonance in medicine

authors： Shemesh N,Jespersen SN,Alexander DC,Cohen Y,Drobnjak I,Dyrby TB,Finsterbusch J,Koch MA,Kuder T,Laun F,Lawrenz M,Lundell H,Mitra PP,Nilsson M,Özarslan E,Topgaard D,Westin CF

更新日期：2016-01-01 00:00:00

abstract：:It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...

journal_title：Magnetic resonance in medicine

authors： Williamson DS,Mulken RV,Jakab PD,Jolesz FA

更新日期：1996-04-01 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：:Phase contrast flow velocity measurements were performed in six healthy volunteers and 30 patients with arteriosclerotic disease. The iliac arteries were investigated in 8 cases and the femoral arteries in 28 cases. In the first 24 patients, 16 evenly distributed data sets were acquired during one cardiac cycle. In th...

journal_title：Magnetic resonance in medicine

authors： Krug B,Kugel H,Harnischmacher U,Heindel W,Schmidt R,Krings F

更新日期：1995-11-01 00:00:00

abstract：:Calibration of the spatial sensitivity functions of coil arrays is a crucial element in parallel magnetic resonance imaging (PMRI). The most common approach has been to measure coil sensitivities directly using one or more low-resolution images acquired before or after accelerated data acquisition. However, since it i...

journal_title：Magnetic resonance in medicine

authors： McKenzie CA,Yeh EN,Ohliger MA,Price MD,Sodickson DK

更新日期：2002-03-01 00:00:00

abstract：:A single slice of z-magnetization is used to generate high-speed images. The slice selection step is achieved using two sin-sinc pulses. This procedure eliminates the need for continual slice gradient reversal, a requirement for the FLASH technique. The RAPID imaging method has less inherent T1 and/or T2 dependence th...

journal_title：Magnetic resonance in medicine

authors： Brooks WM,Brereton IM,Doddrell DM

更新日期：1987-08-01 00:00:00

abstract：:Adipose tissue as well as other depots of fat (triglycerides) are increasingly being recognized as active contributors to the human function and metabolism. In addition to the fat concentration, also the fatty acid chemical composition (FAC) of the triglyceride molecules may play an important part in diseases such as ...

journal_title：Magnetic resonance in medicine

authors： Peterson P,Trinh L,Månsson S

更新日期：2021-01-01 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：PURPOSE:Dynamic phosphorus MR spectroscopic imaging (31 P-MRSI) experiments require temporal resolution on the order of seconds to concurrently assess different muscle groups. A highly accelerated pulse sequence combining flyback echo-planar spectroscopic imaging (EPSI) and compressed sensing was developed and tested i...

journal_title：Magnetic resonance in medicine

authors： Santos-Díaz A,Harasym D,Noseworthy MD

更新日期：2019-06-01 00:00:00