Abstract:
:In this study, Blood Oxygenation Level Dependent (BOLD) contrast in the detection of human brain activation was compared between spin-echo and gradient-echo echo-planar sequences at 1.5 T. Time course series of spin-echo and gradient-echo images containing the primary motor cortex were collected during rest (no finger movement) and activation (finger movement). Each time course series was collected using a different TE. Resting and active state signal intensities at each TE were measured in identical regions in the motor cortex. From these data, resting and active state R2 (1/T2) and R2* (1/T2*) values were obtained. Across four subjects, brain activation produced an average R2 change of -0.16 +/- 0.02/s (+/- SE), and an average R2* change of -0.55 +/- 0.08/s. The average delta R2*/delta R2 ratio was 3.52 +/- 0.56. The average gradient-echo/spin-echo ratio of activation-induced signal changes at the TE for maximal BOLD contrast for each sequence (TE approximately T2* and T2) was calculated to be 1.87 +/- 0.40.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Bandettini PA,Wong EC,Jesmanowicz A,Hinks RS,Hyde JSdoi
10.1002/nbm.1940070104subject
Has Abstractpub_date
1994-03-01 00:00:00pages
12-20issue
1-2eissn
0952-3480issn
1099-1492journal_volume
7pub_type
杂志文章abstract::133Cs NMR is a valuable tool for non-invasively probing biological systems. As a congener of potassium, it accumulates in the intracellular space, primarily through the action of the Na+-K+ pump (ATPase). In addition, it is possible to resolve the MR signal of 133Cs in different tissue compartments on the basis of che...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
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journal_title:NMR in biomedicine
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journal_title:NMR in biomedicine
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journal_title:NMR in biomedicine
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abstract::In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by im...
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abstract::Cerebral edema is a major complication of acute liver failure but may also be seen in other forms of liver failure such as acute-on-chronic liver failure (ACLF) and chronic liver failure (CLF). ACLF develops in patients with previously well-compensated chronic liver disease following acute hepatitis A or E superimpose...
journal_title:NMR in biomedicine
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abstract::The processes of tumor invasion and metastasis have been well characterized at the molecular level, and numerous biomarkers of tumor aggressiveness have been discovered. Molecular imaging offers the opportunity to depict specific cell markers relevant to tumor aggressiveness. Here, we describe the role of MRI in ident...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
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更新日期:2011-07-01 00:00:00
abstract::Structural high-resolution imaging of the brainstem can be of high importance in clinical practice. However, ultra-high field magnetic resonance imaging (MRI) is still restricted in use due to limited availability. Therefore, quantitative MRI techniques (quantitative susceptibility mapping [QSM], relaxation measuremen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4118
更新日期:2019-09-01 00:00:00
abstract::T2 of NAA, creatine and choline-containing compounds were measured in posterior frontal white matter and occipital grey matter in 10 healthy human volunteers. Decay curves comprised signals from eight TE times ranging from 30 to 800 ms with TR 2000 ms acquired with a PRESS sequence on a 1.5 T clinical scanner. Simulat...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.916
更新日期:2005-02-01 00:00:00
abstract::High-energy phosphate metabolism, which allows the synthesis and regeneration of adenosine triphosphate (ATP), is a vital process for neuronal survival and activity. In particular, creatine kinase (CK) serves as an energy reservoir for the rapid buffering of ATP levels. Altered CK enzyme activity, reflecting compromis...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1636
更新日期:2011-08-01 00:00:00
abstract::Spontaneous fluctuations in the blood oxygenation level-dependent (BOLD) MRI signal during the resting state are increasingly being studied in healthy and diseased brain in humans and animal models. Yet, the relationship between functional brain status and the characteristics of spontaneous BOLD fluctuations remains p...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1556
更新日期:2011-01-01 00:00:00
abstract::In vivo 1H MRS is rapidly developing as a clinical tool for diagnosing and characterizing breast cancers. Many in vivo and in vitro experiments have demonstrated that alterations in concentrations of choline-containing metabolites are associated with malignant transformation. In recent years, considerable efforts have...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1217
更新日期:2009-01-01 00:00:00
abstract::The purpose of this study was to investigate the reliability of 3D isotropic MRI and quantitative multi-parametric MRI characterization on an orthotopic pancreatic head tumor model in rats. 3D isotropic T2 -weighted MRI was performed as a routine for tumor longitudinal follow-up and volume estimation. Common bile duct...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3676
更新日期:2017-02-01 00:00:00
abstract::The application of diffusion tensor imaging (DTI) to the evaluation of developing brain remains an area of active investigation. This review focuses on the changes in DTI parameters which accompany both brain maturation and injury. The two primary pieces of information available from DTI studies-water apparent diffusi...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.784
更新日期:2002-11-01 00:00:00
abstract::The presence of the e4 allele of the apolipoprotein E (APOE) gene is the best-known genetic risk factor for Alzheimer's disease. In this study, we investigated the link between functional and behavioural differences and regional brain volume and cortical thickness differences in those who carry the e4 allele (e4+) and...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3502
更新日期:2016-05-01 00:00:00
abstract::Understanding typical, healthy brain development provides a baseline from which to detect and characterize brain anomalies associated with various neurological or psychiatric disorders and diseases. Diffusion MRI is well suited to study white matter development, as it can virtually extract individual tracts and yield ...
journal_title:NMR in biomedicine
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doi:10.1002/nbm.3778
更新日期:2019-04-01 00:00:00
abstract::The measurement of pulmonary perfusion (blood delivered to the capillary bed within a voxel) using arterial spin labeling (ASL) magnetic resonance imaging is often complicated by signal artifacts from conduit vessels that carry blood destined for voxels at a distant location in the lung. One approach to dealing with c...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3358
更新日期:2015-09-01 00:00:00
abstract::Early imaging or blood biomarkers of tumor response is needed to customize anti-tumor therapy on an individual basis. This study evaluates the sensitivity and relevance of five potential MRI biomarkers. Sixty nude rats were implanted with human glioma cells (U-87 MG) and randomized into three groups: one group receive...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1611
更新日期:2011-06-01 00:00:00
abstract::The ability to assess the perfusion territories of major cerebral arteries can be a valuable asset to the diagnosis of a number of cerebrovascular diseases. Recently, several arterial spin labeling (ASL) techniques have been proposed for determining the cerebral perfusion territories of individual arteries by three di...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1177
更新日期:2007-11-01 00:00:00
abstract::This introductory article addresses approaches currently in use to process in vivo spectra. First, a brief overview is given of the information content represented by the parameters of MR signals. Subsequently, common steps in the processing of MR spectra such as pre-processing, normalisation and quantification and th...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.707
更新日期:2001-06-01 00:00:00
abstract::A current limitation of MR spectroscopic imaging of multiple skeletal muscles is prolonged scan duration. A significant reduction in the total scan duration using the echo-planar correlated spectroscopic imaging (EP-COSI) sequence was accomplished using two bipolar readout trains with different phase-encoded echoes fo...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3171
更新日期:2014-10-01 00:00:00
abstract::Mice are used in many studies to determine the role of genetic and molecular factors in mammalian development and human congenital diseases. MRI has emerged as a major method for analyzing mutant and transgenic phenotypes in developing mice, at both embryonic and neonatal stages. Progress in this area is reviewed, wit...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1146
更新日期:2007-05-01 00:00:00
abstract::Under normal conditions, the heart mainly relies on fatty acid oxidation to meet its energy needs. Changes in myocardial fuel preference are noted in the diseased and failing heart. The magnetic resonance signal enhancement provided by spin hyperpolarization allows the metabolism of substrates labeled with carbon-13 t...
journal_title:NMR in biomedicine
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doi:10.1002/nbm.4243
更新日期:2020-03-01 00:00:00
abstract::By combining intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) we introduce a new diffusion model called intravoxel oriented flow (IVOF) that accounts for anisotropy of diffusion and the flow-related signal. An IVOF model using a simplified apparent flow fraction tensor (IVOFf ) is applied to diff...
journal_title:NMR in biomedicine
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doi:10.1002/nbm.3584
更新日期:2016-10-01 00:00:00
abstract::A noise figure and noise parameter measurement system was developed that consists of a combination spectrum and network analyzer, preamplifier, programmable power supply, noise source, tuning board, and desktop computer. The system uses the Y-factor method for noise figure calculation and allows calibrations to correc...
journal_title:NMR in biomedicine
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更新日期:2014-08-01 00:00:00