Quantitative MRI of Gd-DTPA uptake in tumors: response to photodynamic therapy.

abstract：:It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using ...

journal_title：Magnetic resonance in medicine

authors： Riauka TA,De Zanche NF,Thompson R,Vermeulen FE,Capjack CE,Allen PS

更新日期：1999-06-01 00:00:00

abstract：:The magnetization subtraction technique (MS), which is equivalent to the inversion recovery technique in strong magnetic fields, has been implemented in dynamic nuclear polarization-enhanced magnetic resonance imaging (DNPI). The general theoretical basis of the MS method, which can be applied to DNPI or to prepolariz...

journal_title：Magnetic resonance in medicine

authors： Planinsic G,Grucker D,Stepisnik J

更新日期：1996-03-01 00:00:00

abstract：PURPOSE:High angular resolution diffusion imaging (HARDI) is a well-established method to help reveal the architecture of nerve bundles, but long scan times and geometric distortions inherent to echo planar imaging (EPI) have limited its integration into clinical protocols. METHODS:A fast imaging method is proposed he...

journal_title：Magnetic resonance in medicine

authors： Chao TC,Chiou JG,Maier SE,Madore B

更新日期：2017-02-01 00:00:00

abstract：:In some dynamic applications of MRI, only a part of the field-of-view (FOV) actually undergoes dynamic changes. A class of methods, called reduced-FOV (rFOV) methods, convert the knowledge that some part of the FOV is static or not very dynamic into an increase in temporal resolution for the dynamic part, or into a re...

journal_title：Magnetic resonance in medicine

authors： Madore B,Fredrickson JO,Alley MT,Pelc NJ

更新日期：2000-04-01 00:00:00

abstract：:Assuming that the SSFP magnetization response maintains a steady state which is periodic in the presence of diffusion, we can solve for the diffusion effect in such sequences. Formulating a Fourier series decomposition solution to the Bloch-Torrey equation and imposing the steady-state condition, analytical expression...

journal_title：Magnetic resonance in medicine

authors： Carney CE,Wong ST,Patz S

更新日期：1991-06-01 00:00:00

abstract：:High permittivity "dielectric pads" have been shown to increase image quality at high magnetic fields in regions of low radiofrequency transmit efficiency. This article presents a series of electromagnetic simulations to determine the effects of pad size and geometry, relative permittivity value, as well as thickness ...

journal_title：Magnetic resonance in medicine

authors： Teeuwisse WM,Brink WM,Haines KN,Webb AG

更新日期：2012-04-01 00:00:00

abstract：PURPOSE:Anisotropic transverse R2 (1/T2 ) relaxation of water proton is sensitive to cartilage degenerative changes. The purpose is to develop an efficient method to extract this relaxation metric in clinical studies. METHODS:Anisotropic R2 can be measured inefficiently by standard R2 mapping after removing an isotrop...

journal_title：Magnetic resonance in medicine

authors： Pang Y,Palmieri-Smith RM,Malyarenko DI,Swanson SD,Chenevert TL

更新日期：2019-06-01 00:00:00

abstract：:Paramagnetic ions complexed to proteins may lose, retain, or enhance solvent paramagnetic relaxation (SPR) relative to free solution. We measured T1 and T2 of three mouse cancers, their normal counterparts, and six additional tissues. Long T1 of cancers was not caused by necrosis or by different contents of water, fat...

journal_title：Magnetic resonance in medicine

authors： Negendank W,Corbett T,Crowley M,Kellogg C

更新日期：1991-04-01 00:00:00

abstract：PURPOSE:To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). METHODS:A three-step phase correction scheme is proposed to address a) a phase term induce...

journal_title：Magnetic resonance in medicine

authors： Ruschke S,Eggers H,Kooijman H,Diefenbach MN,Baum T,Haase A,Rummeny EJ,Hu HH,Karampinos DC

更新日期：2017-09-01 00:00:00

abstract：:The aim of this work was to identify ventricular shape-based biomarkers in MR images to discriminate between patients with Alzheimer's disease (AD) and healthy elderly. Clinical MR images were collected for 58 patients and 28 age-matched healthy controls. After normalizing all the images the ventricular cerebrospinal ...

journal_title：Magnetic resonance in medicine

authors： Ferrarini L,Palm WM,Olofsen H,van der Landen R,van Buchem MA,Reiber JH,Admiraal-Behloul F

更新日期：2008-02-01 00:00:00

abstract：PURPOSE:We demonstrate the feasibility of MRI with missing-pulse steady-state free precession (MP-SSFP) in a 4T magnet with artificially degraded homogeneity. METHODS:T1 , T2 , and diffusion contrast of MP-SSFP was simulated with constant and alternate radiofrequency (RF) phase using an extended phase graph. To valida...

journal_title：Magnetic resonance in medicine

authors： Kobayashi N,Parkinson B,Idiyatullin D,Adriany G,Theilenberg S,Juchem C,Garwood M

更新日期：2021-02-01 00:00:00

abstract：:Temperature estimation in proton resonance frequency (PRF) shift MR thermometry requires a reference, or pretreatment, phase image that is subtracted from image phase during thermal treatment to yield a phase difference image proportional to temperature change. Referenceless thermometry methods derive a reference phas...

journal_title：Magnetic resonance in medicine

authors： Grissom WA,Lustig M,Holbrook AB,Rieke V,Pauly JM,Butts-Pauly K

更新日期：2010-10-01 00:00:00

abstract：PURPOSE:Compare the transmural distribution of forward creatine kinase reaction (kf,CK ) and ATP hydrolysis rate (kr,ATPase ) in the myocardium of normal porcine heart. Rate constants were extracted from partially relaxed spectra by applying the T1nom method, effectively reducing data acquisition time by up to an order...

journal_title：Magnetic resonance in medicine

authors： Jang A,Xiong Q,Zhang P,Zhang J

更新日期：2016-05-01 00:00:00

abstract：:In this work, a new double quantum filter for glutathione (GSH) editing is introduced, combined with the point-resolved spectroscopy localization sequence (PRESS), and demonstrated in vivo. Compared to the conventional double quantum coherence filter, the new filter has two major advantages. First, it eliminates the n...

journal_title：Magnetic resonance in medicine

authors： Zhao T,Heberlein K,Jonas C,Jones DP,Hu X

更新日期：2006-03-01 00:00:00

abstract：:An arterial spin labeling technique using separate RF labeling and imaging coils was used to obtain multislice perfusion images of the human brain at 3 T. Continuous RF irradiation at a peak power of 0.3 W was applied to the carotid arteries to adiabatically invert spins. Labeling was achieved without producing magnet...

journal_title：Magnetic resonance in medicine

authors： Zaharchuk G,Ledden PJ,Kwong KK,Reese TG,Rosen BR,Wald LL

更新日期：1999-06-01 00:00:00

abstract：PURPOSE:Cross-relaxation imaging (CRI) is a family of quantitative magnetization transfer techniques that utilize images obtained with off-resonance saturation and longitudinal relaxation rate (R1) maps reconstructed by the variable flip angle (VFA) method. It was demonstrated recently that a significant bias in an app...

journal_title：Magnetic resonance in medicine

authors： Mossahebi P,Yarnykh VL,Samsonov A

更新日期：2014-02-01 00:00:00

abstract：:Functional MRI (fMRI) was used to assess proprioceptive-associated cervical cord activity in 24 relapsing multiple sclerosis (MS) patients and 10 controls. Cord and brain conventional and diffusion tensor (DT) MRI were also acquired. fMRI was performed using a block design during a proprioceptive stimulation consistin...

journal_title：Magnetic resonance in medicine

authors： Agosta F,Valsasina P,Rocca MA,Caputo D,Sala S,Judica E,Stroman PW,Filippi M

更新日期：2008-05-01 00:00:00

abstract：:Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid ...

journal_title：Magnetic resonance in medicine

authors： Poulin E,Lebel R,Croteau E,Blanchette M,Tremblay L,Lecomte R,Bentourkia M,Lepage M

更新日期：2013-03-01 00:00:00

abstract：:Sinusoidal capillarization induces microcirculatory changes in liver cirrhosis and fibrosis. The purpose of this study was to assess whether contrast-enhanced MRI can be used to demonstrate the effects of sinusoidal capillarization in liver fibrosis. Dynamic MRI after injection of a low-molecular-weight contrast agent...

journal_title：Magnetic resonance in medicine

authors： Van Beers BE,Materne R,Annet L,Hermoye L,Sempoux C,Peeters F,Smith AM,Jamart J,Horsmans Y

更新日期：2003-04-01 00:00:00

abstract：:Dual labeled liposomes, carrying both paramagnetic and fluorescent lipids, were recently proposed as potent contrast agents for MR molecular imaging. These nanoparticles are coated with poly(ethylene glycol) (PEG) to increase their blood circulation half-life, which should allow extensive accumulation at the targeted ...

journal_title：Magnetic resonance in medicine

authors： van Tilborg GA,Strijkers GJ,Pouget EM,Reutelingsperger CP,Sommerdijk NA,Nicolay K,Mulder WJ

更新日期：2008-12-01 00:00:00

abstract：:The equal-phase line (EPL) algorithm is proposed as a means of allowing rapid Fourier transform (FT) reconstruction of MR image data acquired on a non-Cartesian grid. The pixels on the image are grouped according to their positions. The pixels in a group have the same phase in the complex exponential function -exp[j2p...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Lin J,Jin D

更新日期：2002-06-01 00:00:00

abstract：:We present preliminary results for a 3D finite element calculation to evaluate RF penetration in conducting dielectric materials at high field strengths. A tetrahedral mesh is used along with a Coulomb gauge constraint in a finite element method that yields excellent numerical stability at high frequencies. Accuracy i...

journal_title：Magnetic resonance in medicine

authors： Petropoulos LS,Haacke EM,Brown RW,Boerner E

更新日期：1993-09-01 00:00:00

abstract：:For perfusion-based functional magnetic resonance imaging, the previously introduced flow-sensitive alternating inversion recovery (FAIR) technique is combined with single-shot RARE (rapid acquisition with relaxation enhancement) and GRASE (gradient and spin echo) imaging sequences. The advantages of these sequences c...

journal_title：Magnetic resonance in medicine

authors： Crelier GR,Hoge RD,Munger P,Pike GB

更新日期：1999-01-01 00:00:00

abstract：:The focal underdetermined system solver (FOCUSS) was originally designed to obtain sparse solutions by successively solving quadratic optimization problems. This article adapts FOCUSS for a projection reconstruction MR imaging problem to obtain high resolution reconstructions from angular under-sampled radial k-space ...

journal_title：Magnetic resonance in medicine

authors： Ye JC,Tak S,Han Y,Park HW

更新日期：2007-04-01 00:00:00

abstract：PURPOSE:To investigate the feasibility of estimating calibration constants (K and T2o ) in vivo for converting whole-blood T2 to blood hemoglobin oxygen saturation (HbO2 ) according to the Luz-Meiboom model, 1/T2=1/T2o+K(1-HbO2)2, where K and T2o are relaxivity and transverse relaxation time of fully saturated blood, r...

journal_title：Magnetic resonance in medicine

authors： Langham MC,Rodríguez-Soto AE,Schwartz N,Wehrli FW

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:Classification of pediatric brain tumors from 1 H-magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed diffe...

journal_title：Magnetic resonance in medicine

authors： Zarinabad N,Wilson M,Gill SK,Manias KA,Davies NP,Peet AC

更新日期：2017-06-01 00:00:00

abstract：:Whole-body NMR imaging antennas (probes) are strongly affected by the inevitable magnetic and controllable dielectric losses. Using a convenient parallelepiped model, the magnetic losses are evaluated. By introducing the "ideal power gain," the best possible antenna performance is delimited as a function of the freque...

journal_title：Magnetic resonance in medicine

authors： Sergiadis G

更新日期：1985-08-01 00:00:00

abstract：PURPOSE:To assess the risk of radiofrequency (RF)-induced heating in patients with MR-conditional pacemaker (PM) systems, in the presence of another lead abandoned from a previous implant. METHODS:Four commercial pacemaker leads were placed beside a MR-conditional PM system, inside a human trunk simulator. The phantom...

journal_title：Magnetic resonance in medicine

authors： Mattei E,Gentili G,Censi F,Triventi M,Calcagnini G

更新日期：2015-01-01 00:00:00

abstract：:Parallel excitation is being studied intensively for applications in MR imaging and in particular for selecting arbitrary shapes as regions of interest. In this work, parallel excitation was applied to arbitrarily shaped voxel selection in spectroscopy and investigated for different excitation k-space trajectories (ra...

journal_title：Magnetic resonance in medicine

authors： Snyder J,Haas M,Hennig J,Zaitsev M

更新日期：2012-02-01 00:00:00

abstract：:In past decades, much effort has been invested in developing therapies for spinal injuries. Lack of standardization of clinical read-out measures, however, makes direct comparison of experimental therapies difficult. Damage and therapeutic effects in vivo are routinely evaluated using rather subjective behavioral test...

journal_title：Magnetic resonance in medicine

authors： Stieltjes B,Klussmann S,Bock M,Umathum R,Mangalathu J,Letellier E,Rittgen W,Edler L,Krammer PH,Kauczor HU,Martin-Villalba A,Essig M

更新日期：2006-05-01 00:00:00