Abstract:
:The vascular space occupancy (VASO) method was recently proposed as a functional MRI (fMRI) method that is capable of detecting activation-related changes in blood volume (CBV), without the need for a blood-pool contrast agent. In the present work we introduce a new whole-brain VASO technique that is based on a parallel-accelerated single-shot 3D GRASE (gradient and spin echo) readout. The GRASE VASO sequence employs a flow-compensated correction scheme for concomitant Maxwell gradients which is necessary to avoid smearing artifacts that may occur due to violation of the Carr-Purcell-Meiboom-Gill (CPMG) condition for off-resonance excitation. Experiments with 6 min of visual-motor stimulation were performed on eight subjects. At P < 0.01, average percent signal change and t-score for visual stimulation were -3.11% and -8.42, respectively; activation in left and right motor cortices and supplementary motor area was detected with -2.75% and -6.70, respectively. Sensitivity and signal changes are comparable to those of echo-planar imaging (EPI)-based single-slice VASO, as indicated by additional visual-task experiments (-3.39% and -6.93). The method makes it possible to perform whole-brain cognitive activation studies based on CBV contrast.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Poser BA,Norris DGdoi
10.1002/mrm.22000subject
Has Abstractpub_date
2009-07-01 00:00:00pages
255-62issue
1eissn
0740-3194issn
1522-2594journal_volume
62pub_type
杂志文章abstract:PURPOSE:Evaluate the usefulness of single-shot and of interleaved spatiotemporally encoded (SPEN) methods to perform diffusion tensor imaging (DTI) under various preclinical and clinical settings. METHODS:A formalism for analyzing SPEN DTI data is presented, tailored to account for the spatially dependent b-matrix wei...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26197
更新日期:2017-03-01 00:00:00
abstract:PURPOSE:Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS:Mapping a signa...
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abstract:PURPOSE:Multi-echo spin-echo (MSE) transverse relaxometry mapping using multi-component models is used to study disease activity in neuromuscular disease by assessing the T2 of the myocytic component (T2water ). Current extended phase graph algorithms are not optimized for fat fractions above 50% and the effects of ina...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.28290
更新日期:2020-11-01 00:00:00
abstract::Proton MR spectroscopy ((1)H-MRS) has been used for in vivo quantification of intracellular triglycerides within the sarcolemma. The purpose of this study was to assess whether breath-hold dual-echo in- and out-of-phase MRI at 3.0 T can quantify the fat content of the myocardium. Biases, including T(1), T*(2), and noi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22289
更新日期:2010-04-01 00:00:00
abstract::To investigate the dependency of T(1) relaxation on mechanical strain in articular cartilage, quantitative magnetic resonance T(1) imaging experiments were carried out on cartilage before/after the tissue was immersed in gadolinium contrast agent and when the tissue was being compressed (up to ∼ 48% strains). The spat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22933
更新日期:2011-06-01 00:00:00
abstract:PURPOSE:To improve ultrahigh field diffusion-weighted imaging (DWI) in the presence of inhomogeneous transmit B1 field by designing a novel semi-adiabatic single-refocused DWI technique. METHODS:A 180° slice-selective, adiabatic radiofrequency (RF) pulse of 4 ms duration was designed using the adiabatic Shinnar-Le Rou...
journal_title:Magnetic resonance in medicine
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abstract::Artery wall motion and strain play important roles in vascular remodeling and may be important in the pathogenesis of vascular disease. In vivo observations of circumferentially nonuniform wall motion in the human aorta suggest that nonuniform strain may contribute to the localization of vascular pathology. A velocity...
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更新日期:2004-08-01 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
pub_type: 杂志文章,评审
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更新日期:2021-01-01 00:00:00
abstract::A radiofrequency (RF) time-domain electron paramagnetic resonance (EPR) instrument operating at 300, 600, and 750 MHz was used to image tumor hypoxia with high spatial and temporal resolution. A high-speed signal-averaging Peripheral Component Interconnect (PCI) board with flexibility in the input signal level and the...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.21194
更新日期:2007-04-01 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
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doi:10.1002/mrm.25596
更新日期:2016-03-01 00:00:00
abstract:PURPOSE:Dynamic glucose-enhanced (DGE)-MRI based on chemical exchange-sensitive MRI, that is, glucoCEST and gluco-chemical exchange-sensitive spin-lock (glucoCESL), is intrinsically prone to motion-induced artifacts because the final DGE contrast relies on the difference of images, which were acquired with a time gap o...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28112
更新日期:2020-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22849
更新日期:2011-09-01 00:00:00
abstract:PURPOSE:To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS:Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.25484
更新日期:2015-10-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910330417
更新日期:1995-04-01 00:00:00
abstract::Continuously moving table (CMT) MRI is a new method that is capable of generating 3D, seamless, large field-of-view (FOV) images by acquiring readouts along the patient superior-inferior axis as the subject is translated through the scanner. For applications that require artifact-free images, such as arterial-phase co...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20848
更新日期:2006-05-01 00:00:00
abstract::31P NMR of superfused resting cartilage demonstrated the presence of phosphocreatine in chondrocytes. Changes in pH and in the NTP level were followed during carbon source starvation. From 31P spectra of perchloric acid extracts, phosphoethanolamine, phosphocholine, and the corresponding glycerol diesters were identif...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910250215
更新日期:1992-06-01 00:00:00
abstract::To quantify metabolite and cation concentrations using NMR spectroscopy, the volumes of intracellular and extracellular spaces must be known. We describe a simple 31P NMR spectroscopic method that employs dimethyl methylphosphonate (DMMP) as a marker of total water space and phenylphosphonate (PPA) as a marker of extr...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320206
更新日期:1994-08-01 00:00:00
abstract:PURPOSE:To develop a rapid and motion-robust technique for volumetric MRI, which is based on cross-sectional real-time MRI acquisitions with automatic advancement of the slice position. METHODS:Real-time MRI with a frame-by-frame moving cross-section is performed with use of highly undersampled radial gradient-echo se...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28029
更新日期:2020-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.27971
更新日期:2020-03-01 00:00:00
abstract::One-dimensional spectroscopic imaging of (13)C-4-glutamate turnover is performed in the human brain with a 6 cc nominal voxel resolution at 4T. Data were acquired with an indirect detection approach using a short spin echo single quantum (1)H-(13)C heteronuclear editing method and a 7 cm surface coil with quadrature (...
journal_title:Magnetic resonance in medicine
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doi:10.1002/1522-2594(200011)44:5<673::aid-mrm3>3.0.co
更新日期:2000-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1910060315
更新日期:1988-03-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23191
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:In conventional three-dimensional magnetic resonance elastography, motion encoding gradients (MEGs) synchronized to a mechanical excitation are applied separately in each direction to encode tissue displacement generated by the corresponding waves. This requires long acquisition times that introduce errors due ...
journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.25280
更新日期:2015-04-01 00:00:00
abstract::Quantitative cerebral tissue volumes may be useful for an objective assessment of pathological changes in brain. Accurate determination of tissue volumes is complicated, however, by the partial volume averaging (PVA) effect. We have, therefore, developed a new pulse sequence that minimizes the PVA through the use of i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910390614
更新日期:1998-06-01 00:00:00
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doi:10.1002/mrm.1084
更新日期:2001-04-01 00:00:00
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doi:10.1002/mrm.24774
更新日期:2014-03-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.24737
更新日期:2014-03-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.24137
更新日期:2012-03-01 00:00:00
abstract::Conventional approaches for MR elastography (MRE) using surface drivers have difficulty achieving sufficient shear wave propagation in the prostate gland due to attenuation. In this study we evaluate the feasibility of generating shear wave propagation in the prostate gland using a transurethral device. A novel transu...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22038
更新日期:2009-09-01 00:00:00
abstract::We constructed a device to compress small samples of articular cartilage while the samples were imaged in a 1.5 T imager. With the use of a piezoelectric piston, the device compressed 1-cm-diameter cylindrical samples of articular cartilage (200 microm) at a rate of 2 Hz. Simultaneously, we imaged the samples with a d...
journal_title:Magnetic resonance in medicine
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更新日期:2005-05-01 00:00:00