Spiral trajectory design: a flexible numerical algorithm and base analytical equations.

abstract：:A new ultrafast MR imaging method is proposed and tested, which enables whole-brain fMRI with a true temporal resolution of 1 sec. The method combines a 3D PRESTO pulse sequence with the concept of sensitivity-encoding with multiple receiver coils (SENSE). The so-called PRESTO-SENSE technique is demonstrated on a set ...

journal_title：Magnetic resonance in medicine

authors： Golay X,Pruessmann KP,Weiger M,Crelier GR,Folkers PJ,Kollias SS,Boesiger P

更新日期：2000-06-01 00:00:00

abstract：:A multifocal mouse liver tumor model chemically induced with 5,9-dimethyl-7H-dibenzo[c,g]carbazole was investigated by respiratory-triggered morphological and functional MRI (fMRI) at 4.7 Tesla. The model is characterized by the presence of two tumor types: hypovascular cholangioma and vascularized hepatocellular carc...

journal_title：Magnetic resonance in medicine

authors： Thomas CD,Chenu E,Walczak C,Plessis MJ,Perin F,Volk A

更新日期：2003-09-01 00:00:00

abstract：:The rotationally invariant trace/3 apparent diffusion coefficients (ADC) of N-acetyl aspartate (NAA), creatine and phosphocreatine (tCr), and choline (Cho) were determined using a diffusion-weighted stimulated echo acquisition mode sequence at 3 T in three separate human brain regions, namely the subcortical white mat...

journal_title：Magnetic resonance in medicine

authors： Ellegood J,Hanstock CC,Beaulieu C

更新日期：2005-05-01 00:00:00

abstract：:The detection of free radical reactions in a gelatin sample irradiated by a heavy-ion beam was tested using electron paramagnetic resonance (EPR) spectroscopic and MRI methods. Geometry and the amount of free radical generation in a sample are described. A reaction mixture containing glutathione and a nitroxyl radical...

journal_title：Magnetic resonance in medicine

authors： Matsumoto K,Nagata K,Yamamoto H,Endo K,Anzai K,Aoki I

更新日期：2009-05-01 00:00:00

abstract：:The experiments reported herein are the first MRI investigations of the orientational dependence of T(2) relaxation in articular cartilage at microscopic resolution over the 360 degrees angular space. For each of six canine cartilage specimens, 48 independent T(2)-weighted proton images were acquired for 12 different ...

journal_title：Magnetic resonance in medicine

authors： Xia Y,Moody JB,Alhadlaq H

更新日期：2002-09-01 00:00:00

abstract：:The presence of macroscopic vessels within the tumor region is a potential confounding factor in MR-based dynamic susceptibility contrast (DSC)-enhanced glioma grading. In order to distinguish between such vessels and the elevated cerebral blood volume (CBV) of brain tumors, we propose a vessel segmentation technique ...

journal_title：Magnetic resonance in medicine

authors： Emblem KE,Due-Tonnessen P,Hald JK,Bjornerud A

更新日期：2009-05-01 00:00:00

abstract：:When using tracer kinetic modeling to analyze dynamic contrast-enhanced MRI (DCE-MRI) it is necessary to identify an appropriate arterial input function (AIF). The measured AIF is often poorly sampled in both clinical and preclinical MR systems due to the initial rapid increase in contrast agent concentration and the ...

journal_title：Magnetic resonance in medicine

authors： McGrath DM,Bradley DP,Tessier JL,Lacey T,Taylor CJ,Parker GJ

更新日期：2009-05-01 00:00:00

abstract：:A gradient coil design algorithm capable of controlling the position of the homogeneous region of interest (ROI) with respect to the current-carrying wires is required for many advanced imaging and spectroscopy applications. A modified minimum inductance target field method that allows the placement of a set of constr...

journal_title：Magnetic resonance in medicine

authors： Chronik BA,Rutt BK

更新日期：1998-02-01 00:00:00

abstract：PURPOSE:To evaluate proton density fat fraction (PDFF) and R2* as markers of bone marrow composition and structure in inflamed bone in patients with spondyloarthritis. METHODS:Phantoms containing fat, water, and trabecular bone were constructed with proton density fat fraction (PDFF) and bone mineral density (BMD) val...

journal_title：Magnetic resonance in medicine

authors： Bray TJP,Bainbridge A,Punwani S,Ioannou Y,Hall-Craggs MA

更新日期：2018-02-01 00:00:00

abstract：:Proteoglycan (PG) depletion-induced changes in T1rho (spin-lattice relaxation in rotating frame) relaxation and dispersion in articular cartilage were studied at 4T. Using a spin-lock cluster pre-encoded fast spin echo sequence, T1rho maps of healthy bovine specimens and specimens that were subjected to PG depletion w...

journal_title：Magnetic resonance in medicine

authors： Akella SV,Regatte RR,Gougoutas AJ,Borthakur A,Shapiro EM,Kneeland JB,Leigh JS,Reddy R

更新日期：2001-09-01 00:00:00

abstract：:In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit mo...

journal_title：Magnetic resonance in medicine

authors： Nakai T,Rhine WD,Okada T,Stevenson DK,Spielman DM

更新日期：1998-10-01 00:00:00

abstract：:Proton T2 relaxation and its biexponential components have been determined in rabbit skeletal muscle in the presence and absence of GdDTPA. The effect of GdDTPA, which distributes only in the extracellular space, was greatest in the longer-relaxing T2 component (T22). A 27% reduction in T22 was measured for slow-twitc...

journal_title：Magnetic resonance in medicine

authors： Adzamli IK,Jolesz FA,Bleier AR,Mulkern RV,Sandor T

更新日期：1989-08-01 00:00:00

abstract：:Formation of ternary complexes between Gd-DTPA, Gd-DTPA-BMA, and Gd-DOTA, used as contrast enhancement agents in MRI and the endogenously available carbonate and phosphate ions, has been demonstrated. The extent of ternary complex formation and its effect on the proton relaxation, measured at 9 MHz, rates is negligibl...

journal_title：Magnetic resonance in medicine

authors： Burai L,Hietapelto V,Király R,Tóth E,Brücher E

更新日期：1997-07-01 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：:Noninvasive investigation of aldose reductase activities in rat testis was performed using 3-fluoro-3-deoxy-D-glucose (3-FDG) and nuclear magnetic resonance (NMR) spectroscopy/imaging. Quantitative determination of testis aldose reductase activities, expressed as the sorbitol index, showed a value similar to that of b...

journal_title：Magnetic resonance in medicine

authors： Nakada T,Kwee IL

更新日期：1993-04-01 00:00:00

abstract：:Intermolecular double quantum coherences (iDQCs), signals that result from simultaneous transitions of two or more separated spins, are known to produce images that are highly sensitive to subvoxel structure, particularly local anisotropy. Here we demonstrate how iDQCs signal can be used to efficiently detect the anis...

journal_title：Magnetic resonance in medicine

authors： Branca RT,Chen YM,Mouraviev V,Galiana G,Jenista ER,Kumar C,Leuschner C,Warren WS

更新日期：2009-04-01 00:00:00

abstract：:Aim of the study was to determine distribution and depletion patterns of intramyocellular lipids (IMCL) in leg muscles before and after two types of standardized endurance exercise. ¹H-magnetic resonance spectroscopic imaging was performed (1) in the thigh of eight-trained cyclists after exercising on an ergometer for...

journal_title：Magnetic resonance in medicine

authors： Vermathen P,Saillen P,Boss A,Zehnder M,Boesch C

更新日期：2012-11-01 00:00:00

abstract：PURPOSE:Proof-of-concept study of mapping renal blood flow vector field according to the inverse solution to a mass transport model of time resolved tracer-labeled MRI data. THEORY AND METHODS:To determine tissue perfusion according to the underlying physics of spatiotemporal tracer concentration variation, the mass t...

journal_title：Magnetic resonance in medicine

authors： Zhou L,Zhang Q,Spincemaille P,Nguyen TD,Morgan J,Dai W,Li Y,Gupta A,Prince MR,Wang Y

更新日期：2021-04-01 00:00:00

abstract：PURPOSE:To improve imaging performance for body MRI with a local transmit array at 10.5T, the geometry of a dipole antenna was optimized to achieve lower peak specific absorption rate (SAR) levels and a more uniform transmit profile. METHODS:Electromagnetic simulations on a phantom were used to evaluate the SAR and ...

journal_title：Magnetic resonance in medicine

authors： Steensma B,van de Moortele PF,Ertürk A,Grant A,Adriany G,Luijten P,Klomp D,van den Berg N,Metzger G,Raaijmakers A

更新日期：2020-11-01 00:00:00

abstract：:This study aims to assess whether an alternative method, that is based on volumetric surface detection (VoSD) without tracing and is totally free of geometric assumptions, can improve the reproducibility of right ventricular (RV) volume quantification from cardiac magnetic resonance (CMR) images, in comparison with a ...

journal_title：Magnetic resonance in medicine

authors： Catalano O,Corsi C,Antonaci S,Moro G,Mussida M,Frascaroli M,Baldi M,Caiani E,Lamberti C,Cobelli F

更新日期：2007-03-01 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

abstract：:A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equatio...

journal_title：Magnetic resonance in medicine

authors： Olsson MB,Wirestam R,Persson BR

更新日期：1995-10-01 00:00:00

abstract：PURPOSE:Irreversible electroporation (IRE) is a nonthermal tissue ablation technique that represents a promising treatment option for unresectable liver tumors, but the effectively treated zone cannot be reliably predicted. We investigate the potential benefit of transcatheter intra-arterial perfusion (TRIP) -MRI for t...

journal_title：Magnetic resonance in medicine

authors： Figini M,Zhou K,Pan L,Sun C,Wang B,Hu S,Yang J,Shangguan J,Eresen A,Velichko Y,Yaghmai V,Zhang Z

更新日期：2020-07-01 00:00:00

abstract：PURPOSE:To accelerate dynamic MR applications using infimal convolution of total generalized variation functionals (ICTGV) as spatio-temporal regularization for image reconstruction. THEORY AND METHODS:ICTGV comprises a new image prior tailored to dynamic data that achieves regularization via optimal local balancing b...

journal_title：Magnetic resonance in medicine

authors： Schloegl M,Holler M,Schwarzl A,Bredies K,Stollberger R

更新日期：2017-07-01 00:00:00

abstract：:The authors introduce several sets of time-efficient gradient waveforms for applying isotropic diffusion weighting in NMR experiments. This creates signal attenuation that depends on the trace of the diffusion tensor and is therefore rotationally invariant. Numerical methods for the calculation of such gradient sets a...

journal_title：Magnetic resonance in medicine

authors： Wong EC,Cox RW,Song AW

更新日期：1995-08-01 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：:The combination of an in-plane B(1) sensitivity encoding (SENSE) technique with a simultaneous multiple-slice B(0) field step technique (multiple-acquisition micro B(0) array (MAMBA)) has produced high scan time reduction factors (R < or = 8). In this study, two slices were acquired simultaneously in combination with ...

journal_title：Magnetic resonance in medicine

authors： Paley MN,Lee KJ,Wild JM,Fichele S,Whitby EH,Wilkinson ID,Van Beek EJ,Griffiths PD

更新日期：2003-06-01 00:00:00

abstract：:It is demonstrated that the stability of the Carr-Purcell-Meiboom-Gill (CPMG) sequence reflects the existence of a steady state solution to the Bloch equations in the absence of T2 and T1 decay. The steady state theory is then used to evaluate the performance of low flip angle RARE imaging sequences with both constant...

journal_title：Magnetic resonance in medicine

authors： Alsop DC

更新日期：1997-02-01 00:00:00

abstract：:Previous theoretical reports described the dependence of interpretation of the observed phase of the NMR signal on the time origin(s) of moment calculations and position's Taylor series expansion. This work provides experimental confirmation of predictions derived from that theory. For accelerative motion, experimenta...

journal_title：Magnetic resonance in medicine

authors： Duerk JL,Simonetti OP,Hurst GC,Finelli DA

更新日期：1994-07-01 00:00:00

abstract：:Regional values of fractional anisotropy (FA) and mean diffusivity (D(av)) of in vivo and excised rat spinal cords were measured using an iscosahedral encoding scheme that is based on 21 uniformly distributed and alternating gradient directions with an echo planar imaging (EPI) readout. Based on the water phantom stud...

journal_title：Magnetic resonance in medicine

authors： Madi S,Hasan KM,Narayana PA

更新日期：2005-01-01 00:00:00