Bayesian multipoint velocity encoding for concurrent flow and turbulence mapping.

abstract：PURPOSE:MR fingerprinting (MRF) is a technique for quantitative tissue mapping using pseudorandom measurements. To estimate tissue properties such as T1 , T2 , proton density, and B0 , the rapidly acquired data are compared against a large dictionary of Bloch simulations. This matching process can be a very computation...

journal_title：Magnetic resonance in medicine

authors： Cauley SF,Setsompop K,Ma D,Jiang Y,Ye H,Adalsteinsson E,Griswold MA,Wald LL

更新日期：2015-08-01 00:00:00

abstract：:Diffusion-weighted imaging suffers from motion artifacts and relatively low signal quality due to the long echo times required to permit the diffusion encoding. We investigated the inclusion of a noncylindrical fourth gradient coil, dedicated entirely to diffusion encoding, into the imaging system. Standard three-axis...

journal_title：Magnetic resonance in medicine

authors： Feldman RE,Scholl TJ,Alford JK,Handler WB,Harris CT,Chronik BA

更新日期：2011-12-01 00:00:00

abstract：:Focused ultrasound heating of ex vivo bovine kidney and liver was monitored using magnetic resonance imaging (MRI) to investigate the quantitative relationship between time-dependent temperature elevations and altered contrast in MR images due to thermal coagulation. Proton resonance frequency shift MR thermometry was...

journal_title：Magnetic resonance in medicine

authors： Graham SJ,Chen L,Leitch M,Peters RD,Bronskill MJ,Foster FS,Henkelman RM,Plewes DB

更新日期：1999-02-01 00:00:00

abstract：:The image intensity in magnetic resonance magnitude images in the presence of noise is shown to be governed by a Rician distribution. Low signal intensities (SNR < 2) are therefore biased due to the noise. It is shown how the underlying noise can be estimated from the images and a simple correction scheme is provided ...

journal_title：Magnetic resonance in medicine

authors： Gudbjartsson H,Patz S

更新日期：1995-12-01 00:00:00

abstract：PURPOSE:To characterize pseudo-continuous arterial spin labeling (pCASL) through simulations of spin inversion and to discuss suitable parameter settings for measuring cerebral perfusion. METHODS:Simulations of arterial spin inversion in pCASL were performed based on the Bloch equation. Both the labeling and the contr...

journal_title：Magnetic resonance in medicine

authors： Lorenz K,Mildner T,Schlumm T,Möller HE

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:Treatments using high-intensity focused ultrasound (HIFU) in the abdominal region remain challenging as a result of respiratory organ motion. A novel method is described here to achieve 3D motion-compensated ultrasound (US) MR-guided HIFU therapy using simultaneous ultrasound and MRI. METHODS:A truly hybrid US...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Manasseh G,Petrusca L,Scheffler K,Auboiroux V,Crowe LA,Hyacinthe JN,Natsuaki Y,Santini F,Becker CD,Terraz S,Bieri O,Salomir R

更新日期：2018-05-01 00:00:00

abstract：:Human cardiac 31P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31P metabolites...

journal_title：Magnetic resonance in medicine

authors： Meininger M,Landschütz W,Beer M,Seyfarth T,Horn M,Pabst T,Haase A,Hahn D,Neubauer S,von Kienlin M

更新日期：1999-04-01 00:00:00

abstract：:In echo-planar-based diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI), the evaluation of diffusion parameters such as apparent diffusion coefficients and anisotropy indices is affected by image distortions that arise from residual eddy currents produced by the diffusion-sensitizing gradients. Correc...

journal_title：Magnetic resonance in medicine

authors： Bodammer N,Kaufmann J,Kanowski M,Tempelmann C

更新日期：2004-01-01 00:00:00

abstract：:When deoxygenated, blood behaves as an effective susceptibility contrast agent. Changes in brain oxygenation can be monitored using gradient-echo echo-planar imaging. With this technique, difference images also demonstrate that blood oxygenation is increased during periods of recovery from respiratory challenge. ...

journal_title：Magnetic resonance in medicine

authors： Turner R,Le Bihan D,Moonen CT,Despres D,Frank J

更新日期：1991-11-01 00:00:00

abstract：:Motion-sensitive phase contrast magnetic resonance imaging and magnetic resonance elastography are applied for the measurement of volumetric strain and tissue compressibility in human brain. Volumetric strain calculated by the divergence operator using a biphasic effective-medium model is related to dilatation and com...

journal_title：Magnetic resonance in medicine

authors： Hirsch S,Klatt D,Freimann F,Scheel M,Braun J,Sack I

更新日期：2013-09-01 00:00:00

abstract：:In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic 13C NMR techniques in the presence and absence of dichl...

journal_title：Magnetic resonance in medicine

authors： Rath DP,Zhu H,Tong X,Jiang Z,Hamlin RL,Robitaille PM

更新日期：1997-12-01 00:00:00

abstract：:Chemical exchange saturation transfer (CEST), arterial spin labeling (ASL), and magnetization transfer contrast (MTC) methods generate different contrasts for MRI. However, they share many similarities in terms of pulse sequences and mechanistic principles. They all use RF pulse preparation schemes to label the longit...

journal_title：Magnetic resonance in medicine

authors： Knutsson L,Xu J,Ahlgren A,van Zijl PCM

更新日期：2018-10-01 00:00:00

abstract：:Algorithms to reliably detect motion in navigator echoes are crucial to many MRI motion suppression techniques. The accuracy of these algorithms is affected by noise and deformation of navigator echo profile caused by physiologic motion. This study compared the performance of algorithms based on correlation and least ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Grimm RC,Felmlee JP,Riederer SJ,Ehman RL

更新日期：1996-07-01 00:00:00

abstract：PURPOSE:To test the efficacy of 7T MRS for in vivo detection of 2-hydroxyglutarate (2HG) in brain tumors. METHODS:The subecho times of point-resolved spectroscopy (PRESS) were optimized at 7T with density-matrix simulations and phantom validation to improve the 2HG signal selectivity with respect to the neighboring re...

journal_title：Magnetic resonance in medicine

authors： Ganji SK,An Z,Tiwari V,McNeil S,Pinho MC,Pan E,Mickey BE,Maher EA,Choi C

更新日期：2017-03-01 00:00:00

abstract：PURPOSE:To obtain multicontrast images including fat-suppressed contrast image, a novel multicontrast imaging method using an SSFP sequence with alternating RF flip angles is proposed. METHODS:The proposed method uses the balanced SSFP sequence with 2 flip angles. In general, the conventional balanced SSFP sequence ha...

journal_title：Magnetic resonance in medicine

authors： Kim J,Seo H,So S,Park H

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. METHODS:The difference in ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Zhang Y,Zhao X,Wu B,Gao JH

更新日期：2017-11-01 00:00:00

abstract：:Fitting a model to an experimental spectrum is a difficult nonlinear estimation problem. The solution presented here is to start an iterative search procedure sufficiently close to the optimal model parameter set. This is achieved by providing tissue-dependent a priori peak information and by a novel correlation metho...

journal_title：Magnetic resonance in medicine

authors： Burger C,McKinnon G,Buchli R,Boesiger P

更新日期：1991-10-01 00:00:00

abstract：:The cytosol of intact human red blood cells was loaded with 28.1 +/- 3.4 mM of dysprosium DTPA-BMA using a hypoosmotic technique. When loaded cells were diluted with saline and control cells to give an average dysprosium concentration of 3.3 +/- 0.5 mM, the transverse relaxation rate constants R(*)(2) and R(2) increas...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Tao JZ,Kennan RP,Gore JC

更新日期：2001-05-01 00:00:00

abstract：:Problems with in vivo proton spectroscopy include strong water and lipid signals, and the very complicated structures of the spectra. Multiple-quantum experiments can be designed to overcome these difficulties. Using a volume selective refocusing technique, one can demonstrate how multiple-quantum experiments can be p...

journal_title：Magnetic resonance in medicine

authors： McKinnon GC,Bosiger P

更新日期：1988-03-01 00:00:00

abstract：:T(2) quantification may augment diagnostic T(2)-weighted imaging; to improve cancer detection via auto-segmentation of multi-parametric acquisitions and to potentiate longitudinal studies of prostate cancer. However, robust quantitative techniques are not generally accessible or refined for clinical translation. This ...

journal_title：Magnetic resonance in medicine

authors： Foltz WD,Chopra S,Chung P,Bayley A,Catton C,Jaffray D,Wright GA,Haider MA,Ménard C

更新日期：2010-10-01 00:00:00

abstract：PURPOSE:Define criteria for selection of optimal flip angle sets for T1 estimation and evaluate effects on T1 mapping. THEORY AND METHODS:Flip angle sets for spoiled gradient echo-based T1 mapping were selected by minimizing T1 estimate variance weighted by the joint density of M0 and T1 in an initial acquisition. The...

journal_title：Magnetic resonance in medicine

authors： Lewis CM,Hurley SA,Meyerand ME,Koay CG

更新日期：2016-09-01 00:00:00

abstract：:High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered...

journal_title：Magnetic resonance in medicine

authors： Herlihy AH,Oatridge A,Curati WL,Puri BK,Bydder GM,Hajnal JV

更新日期：2001-08-01 00:00:00

abstract：PURPOSE:A target-pattern-driven (TD) trajectory design is introduced in combination with parallel transmit (pTX) radiofrequency (RF) pulses to provide localized suppression of unwanted signals. The design incorporates target-pattern and B1+ information to adjust denser sampling and coverage in k-space regions where the...

journal_title：Magnetic resonance in medicine

authors： Schneider R,Haueisen J,Pfeuffer J

更新日期：2014-10-01 00:00:00

abstract：PURPOSE:To investigate Shift Undersampling improves Parametric mapping Efficiency and Resolution (SUPER), a novel blockwise curve-fitting method for accelerating parametric mapping with very fast reconstruction. METHODS:SUPER uses interleaved k-space undersampling, which enables a blockwise decomposition of the otherw...

journal_title：Magnetic resonance in medicine

authors： Hu C,Peters DC

更新日期：2019-06-01 00:00:00

abstract：:Measuring T(2) at 7.0 T is not trivial due to RF inhomogeneity effects, however, gradient echo sampling of a spin echo is insensitive to RF pulse errors, does not suffer from significant distortions, and allows T'(2) and T(2) to be estimated simultaneously. Gradient echo sampling of a spin echo results are relatively ...

journal_title：Magnetic resonance in medicine

authors： Cox EF,Gowland PA

更新日期：2010-11-01 00:00:00

abstract：PURPOSE:To develop a method to use information from multiple MRI contrasts to produce a composite angiogram with reduced sequence-specific artifacts and improved vessel depiction. METHODS:Bayesian posterior vessel probability was determined as a function of black blood (BB), contrast enhanced angiography (CE-MRA), and...

journal_title：Magnetic resonance in medicine

authors： Kim D,Edjlali M,Turski P,Johnson KM

更新日期：2020-03-01 00:00:00

abstract：PURPOSE:To test the hypothesis that a noninvasive dynamic contrast enhanced MRI (DCE-MRI) derived interstitial volume fraction (ve ) and/or distribution volume (VD ) were correlated with tumor cellularity in cerebral tumor. METHODS:T1 -weighted DCE-MRI studies were performed in 18 athymic rats implanted with U251 xeno...

journal_title：Magnetic resonance in medicine

authors： Aryal MP,Nagaraja TN,Keenan KA,Bagher-Ebadian H,Panda S,Brown SL,Cabral G,Fenstermacher JD,Ewing JR

更新日期：2014-06-01 00:00:00

abstract：PURPOSE:To examine the detection sensitivity for the rapidly exchanging hydroxyl protons of D-glucose using the recently developed on-resonance variable delay multi-pulse (onVDMP) chemical exchange saturation transfer (CEST) technique. METHODS:The onVDMP method was applied for the detection of water signal changes upo...

journal_title：Magnetic resonance in medicine

authors： Xu X,Xu J,Chan KWY,Liu J,Liu H,Li Y,Chen L,Liu G,van Zijl PCM

更新日期：2019-01-01 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：:Partially parallel imaging strategies such as SMASH, SENSE, and PILS rely on the sensitivity distribution of phased array RF coils to reduce MRI imaging time. Using an N-element phased array, these techniques allow maximum accelerations, L, such that L < or = N, with acceleration defined as the factor by which scan ti...

journal_title：Magnetic resonance in medicine

authors： Bankson JA,Wright SM

更新日期：2002-04-01 00:00:00